CARTA GEOLOGICA D’ITALIA

APAT Agenzia per la protezione dell’ambiente e per i servizi tecnici DIPARTIMENTO DIFESA DEL SUOLO S e r v i z i o G e o l o g i c o d’I t a l i a Organo Cartografico dello Stato (legge n°68 del 2.2.1960) MEMORIE DESCRITTIVE DELLA CARTA GEOLOGICA D’ITALIA VOLUME LXXIV INTENSITY SCALE ESI 2007 La Scala di Intensità ESI 2007 Authors A.M. MICHETTI, E. ESPOSITO, L. GUERRIERI, S. PORFIDO, L. SERVA, R. TATEVOSSIAN, E. VITTORI, F. AUDEMARD, T. AZUMA, J. CLAGUE, V. COMERCI, A. GÜRPINAR, J. MCCALPIN, B. MOHAMMADIOUN, N.A. MÖRNER, Y. OTA, E. ROGHOZIN Editors GUERRIERI L., VITTORI E. SYTEMCART - 2007 Direttore responsabile: Leonello SERVA REDAZIONE a cura del Servizio Cartografico, coordinamento base dati e tavoli europei Dirigente: Norman ACCARDI Capo Settore: Domenico TACCHIA Coordinamento Editoriale, allestimento digitale dei testi: Maria Luisa VATOVEC SYSTEMCART - 2007 Preface The idea of an Intensity scale based on coseismic environmental effects started to ripe early in the '80s following the macroseismic surveys of strong earthquakes, in particular, for Italy, those occurred in 1976 (Friuli) and 1980 (Irpinia-Basilicata). In fact, during such surveys, it was often observed that intensity could not be reliably evaluated only based on damage to artefacts. This was specially true for sparsely populated areas and for the highest degrees, because it was extremely difficult to estimate damage above degree X. Environmental effects, although sometimes widespread, were generally overlooked even if some of them do not suffer of such limitations. Among them was particularly impressive the observation of jumping stones, which sometimes were found higher than their original position, clear evidence of peak acceleration exceeding gravity. It must be underlined that the compilers of the earlier macroseismic scales already at the end of XIX century judged useful to define the intensity degree based on effects not only on man and man-made structures, but also on the environment. The intensity scale ESI 2007 (Environmental Seismic Intensity scale) results from a reviewing process of previous versions lasted for eight years and carried out also under the patronage of INQUA (International Union for Quaternary Research). To this revision have participated many qualified geologists, seismologists and engineers from many countries, under the coordination of the Italian Geological Survey of the Italian Environmental Agency. The ESI scale does not substitute the traditional ones, but integrates them, allowing to define the earthquake intensity on the basis of the whole set of coseismic effects. It can be applied not only to future earthquakes, but also to reassess historical events. Therefore, I believe that, if properly applied, the ESI scale will provide valuable information in many areas for a better assessment of seismic hazard. Prefazione L’idea di una scala di intensità basata sugli effetti cosismici sull’ambiente è iniziata a maturare a partire dagli anni '80 a seguito dei rilievi macrosismici di forti terremoti, in particolare per l’Italia quelli del 1976 (Friuli) e 1980 (IrpiniaBasilicata). Infatti, nel corso di tali rilievi si osservava spesso che l’intensità non poteva essere stimata in maniera affidabile sulla base dei soli danni sul costruito. Ciò valeva in particolare per le aree scarsamente abitate e per i terremoti più forti, in quanto risultava estremamente complesso stimare il danneggiamento sopra il decimo grado. Gli effetti ambientali, pur talora numerosi e diffusi su tutto il territorio venivano invece trascurati sebbene alcuni di loro non soffrissero di simili limitazioni (tra essi, l’effetto che più mi colpiva erano le impronte sul terreno di sassi che si ritrovavano nelle immediate vicinanze, anche a monte, indicazione sicura di picchi di accelerazione superiori a quello di gravità). Va detto che gli Autori delle prime scale macrosismiche già alla fine del XIX secolo avevano ritenuto utile definire il grado d’intensità sulla base degli effetti non solo sull’uomo e sulle strutture antropiche, ma anche sull’ambiente naturale. La scala di intensità ESI 2007 (Environmental Seismic Intensity scale) è il risultato di un processo di revisione delle precedenti versioni durato otto anni e realizzato anche nell’ambito delle attività dell’INQUA (International Union for Quaternary Research). A tale revisione hanno collaborato numerosi e qualificatissimi geologi, sismologi e ingegneri provenienti da varie parti del mondo coordinate dal Servizio Geologico d’Italia dell’APAT. La scala ESI 2007 non si sostituisce a quelle tradizionali ma le integra, consentendo di definire l'intensità sismica sulla base di tutti gli effetti a disposizione. Essa è potenzialmente utilizzabile non solo per terremoti futuri ma anche per la revisione di terremoti storici. Pertanto, sono convinto che, se adottata correttamente, la scala ESI 2007 potrà fornire in molte aree utili indicazioni anche per la rivalutazione della pericolosità sismica. Il Direttore del Servizio Geologico d’Italia / Dipartimento Difesa del Suolo Dr. Leonello SERVA Environmental Seismic Intensity scale - ESI 2007 La scala di Intensità Sismica basata sugli effetti ambientali - ESI 2007 MICHETTI A.M. (1), ESPOSITO E. (2), GUERRIERI L. (3), PORFIDO S. (2), SERVA L. (3), TATEVOSSIAN R. (4), VITTORI E. (3), AUDEMARD F. (5), AZUMA T. (6), CLAGUE J. (7), COMERCI V. (3), GÜRPINAR A. (8), MC CALPIN J. (9), MOHAMMADIOUN B. (10), MÖRNER N.A. (11), OTA Y. (12), ROGHOZIN E. (4) ABSTRACT - The Environmental Seismic Intensity scale (ESI 2007) is a new earthquake intensity scale only based on the effects triggered by the earthquake in the natural environment. The coseismic effects considered more diagnostic for intensity evaluation are surface faulting and tectonic uplift/subsidence (primary effects), landslides, ground cracks, liquefactions, displaced boulders, tsunami and hydrological anomalies (secondary effects). The ESI 2007 scale follows the same basic structure as any other XII degree scale, such as the MCS, MM, MSK and EMS scales. This type of intensity scale was proposed to the scientific community since the beginning of '90s. The idea was definitely accepted in 1999, when a first version of the scale was developed by a Working Group of geologists, seismologists and engineers sponsored by the International Union for Quaternary Research (INQUA). In the following years, this version has been revised and updated. The ESI 2007 scale is the result of the revision of previous versions after its application to a large number of earthquakes worldwide. In the frame of INQUA SubCommission on Paleoseismicity, this activity was conducted by academic and research institutes coordinated by the Geological Survey of Italy - APAT (for further details, s e e h t t p : / / w w w. a p a t . g o v. i t / s i t e / e n GB/Projects/INQUA_Scale/default.html). For intensity levels lower than IX, the main goal of this new scale is to bring the environmental effects in line with the damage indicators. In this range, the ESI 2007 scale should be used along with the other scales. In the range between X and XII, the distribution and size of environmental effects, specially primary tectonic features, becomes the most diagnostic tool to assess the intensity level. Documentary report and/or field observations on fault rupture length and surface displacement should be consistently implemented in the macroseismic study of past and future earthquakes. Therefore, the use of the ESI 2007 alone is recommen- ded only when effects on humans and on manmade structures i) are absent, or too scarce (i.e. in sparsely populated or desert areas), and ii) saturate (i.e., for intensity X to XII) loosing their diagnostic value. After its official approval at the 17th INQUA Congress, the use of the ESI 2007 scale will be proposed to national institutions (geological surveys, academic and research institutes, departments for civil protection, environmental agencies, etc.), dealing in the field of earthquake intensity and seismic hazard. RIASSUNTO - L’Environmental Seismic Intensity scale (ESI 2007) è una nuova scala di intensità dei terremoti basata esclusivamente sugli effetti ambientali. Tra questi, quelli considerati diagnostici per la valutazione dell’intensità sono la fagliazione superficiale e i sollevamenti/abbassamenti tettonici (effetti primari), i fenomeni franosi, le fratture, le liquefazioni, gli tsunami, le variazione idrologiche (effetti secondari). La scala ESI 2007 è strutturata come le altre scale a XII gradi, quali le scale MCS, MM, MSK ed EMS. Già dagli anni '90 questo tipo di scala di intensità veniva proposta all’interno della comunità scientifica per essere successivamente accolta e sviluppata in ambito internazionale, sotto l’egida dell’INQUA (International Union for Quaternary Research), da un Gruppo di Lavoro costituito da geologi, sismologi e ingegneri. Nel 1999 ne veniva redatta una prima versione, più volte aggiornata negli anni successivi. La versione ESI 2007 è il risultato della revisione delle precedenti sulla scorta delle informazioni ottenute attraverso l’applicazione della scala a un gran numero di terremoti in tutto il mondo. Tale attività è stata condotta, nell’ambito dell’INQUA SubCommission on Paleoseismicity, da Università e Istituti di ricerca a livello internazionale coordinati dal Dipartimento Difesa del Suolo - Servizio Geologico d’Italia dell’APAT (per maggiori dettagli (1) Università dell’Insubria, Como, Italy. (2) Istituto per l’Ambiente Marino Costiero, CNR, Napoli, Italy. (3) Geological Survey of Italy, APAT, Roma, Italy. (4) Russian Academy of Sciences, Moscow, Russia. (5) FUNVISIS, Caracas, Venezuela. (6) National Institute of Advanced Industrial Science and Technology, Tokyo, Japan. (7) Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia, Canada. (8) IAEA, Vienna, Austria. (9) GEO-HAZ Consulting, Crestone, Colorado, USA. (10) Robinswood Consultant, Saint Martin de Nigelles, France. (11) Institute for Paleogeodynamics & Paleogeophysics, Stockolm , Sweden. (12) Emeritous of Yokohama National University, Japan. 8 MICHETTI A.M. ET ALII h t t p : / / w w w. a p a t . g o v. i t / s i t e / e n GB/Projects/INQUA_Scale/default.html). Per livelli di intensità inferiori a IX, lo scopo principale di questa nuova scala è quello di considerare gli effetti ambientali alla stessa stregua degli indicatori di danneggiamento. In questo intervallo di intensità, la scala ESI 2007 deve essere utilizzata insieme alle altre scale d'intensità. Tra il X e il XII grado, la distribuzione e le dimensioni degli effetti tettonici primari costituiscono l’indicatore maggiormente diagnostica per la valutazione dell’intensità. Le descrizioni delle caratteristiche della fagliazione superficiale (lunghezza della rottura; massima dislocazione verticale) dovrebbe essere riportata in maniera consistente negli studi macrosismici dei terremoti passati e futuri. L’utilizzo della scala ESI 2007 come unico e indipendente strumento di valutazione deve essere utilizzata solamente quando gli effetti sull’uomo e sulle strutture antropiche i) sono assenti o troppo scarsi (es. aree deserte o scarsamente abitate) oppure ii) arrivano a saturazione (per intensità comprese tra X e XII). Al fine di promuoverne un utilizzo più condiviso e ampio possibile, la scala ESI 2007, che verrà ufficializzata durante il 17th INQUA Congress, sarà proposta alle istituzioni (servizi geologici nazionali, istituti di ricerca in campo sismologico, dipartimenti di protezione civile, agenzie ambientali) che nei vari Paesi si occupano della valutazione dell’intensità dei terremoti e della pericolosità sismica. 1. - INTRODUCTION In 1999, during the 15th INQUA (International Union for Quaternary Research) Congress in Durban, the Subcommission on Paleoseismicity promoted the compilation of a new scale of macroseismic intensity based only on environmental effects. A Working Group including geologists, seismologists and engineers compiled a first version of the scale, that was presented at the 16th INQUA Congress in Reno (July 23 - 30, 2003), and updated one year later at the 32nd International Geological Congress in Florence (MICHETTI et alii, 2004). To this end, the INQUA TERPRO (Commission on Terrestrial Processes) approved a specific project (INQUA Scale Project, 2004 - 2007) with the aim of A) testing the scale for a trial period of 4 years, coincident with the intercongress cycle, B) reviewing the first version through its application to case studies worldwide(1) , and C) submitting the revised version so as to be ratified during the 17th INQUA Congress in Cairns (July 28 - August 3, 2007). The 2004 version of this scale was provisionally named INQUA EEE scale, where EEE stands for Earthquake Environmental Effects. This document describes the revised version of the scale, which is formally named Environmental Seismic Intensity scale - ESI 2007. The IES 2007 scale is composed by: a) Definition of intensity degrees on the basis of Earthquake Environmental Effects, i.e. the scale itself, which follows the same basic structure of the widely used twelve degrees macroseismic scales (see MICHETTI et alii, 2004); b) Guidelines, which aim at better clarifying i) the background of the scale and the scientific concepts that support the introduction of such a new macroseismic scale; ii) the procedure to use the scale alone or integrated with damage-based, traditional scales; iii) how the scale is organized; iv) the descriptions of diagnostic features required for intensity assessment, and the meaning of idioms, colors, and fonts. A gallery of photographs kindly provided by numerous scientists involved in the INQUA Scale Project are reported in Appendix I. The ESI 2007 Form (Appendix II) is an helpful tool for data collection of Earthquake Environmental Effects. The Plate I (Appendix III) reports the definition of intensity degrees in a synoptic table, classified by the category of Earthquake Environmental Effect. Both these latter documents have been designed for the application of the ESI 2007 scale during field surveys immediately after the seismic event. (1) The application of the INQUA scale to case studies was conducted within the INQUA Scale Project Working Group by the Authors and by the following scientists: · R. AMIT - Geological Survey of Israel. · G. BESANA - Nagoya University, Furo-cho Chikusa-ku, Nagoya, Aichi, Japan. · K. CHUNGA - Università dell’Insubria, Como, Italy. · A. FOKAEFS - Institute of Geodynamics, National Observatory of Athens, Greece. · L.E. FRANCO - INGEOMINAS, Bogotà, Colombia. · C.P. LALINDE PULIDO - Universidad EAFIT, Departamiento de Ciencias de la Tierra, Medellin, Colombia. · E. KHAGAN - Geological Survey of Israel. · N. LIN YUNONG - National Taiwan University, Taiwan. · S. MARCO - Department of Geophysics and Planetary Sciences, Tel Aviv, Israel. · A. NELSON - US Geological Survey, Denver, USA. · I. PAPANIKOLAU - University College London, Department of Earth Sciences, BHRC, London, UK. · G. PAPATHANASSIOU - Aristotle University of Thessaloniki, Greece. · S. PAVLIDES - Aristotle University of Thessaloniki, Greece. · K. REICHERTER - Aachen University, Germany. · A. SALAMON - Geological Survey of Israel. · C. SPERNANZONI - University of Roma Tre, Italy. · P.G. SILVA - Departamento de Geología, Universidad de Salamanca Sapin. · J. ZAMUDIO - Istituto Geofisico del Perù, Lima. Definition of intensity degrees Definizione dei gradi di intensità From I to III: There are no environmental effects that can be used as diagnostic. IV - LARGELY OBSERVED - First unequivocal effects in the environment Primary effects are absent. Secondary effects: a) Rare small variations of the water level in wells and/or of the flow-rate of springs are locally recorded, as well as extremely rare small variations of chemical-physical properties of water and turbidity in springs and wells, especially within large karstic spring systems, which appear to be most prone to this phenomenon. b) In closed basins (lakes, even seas) seiches with height not exceeding a few centimeters may develop, commonly observed only by tidal gauges, exceptionally even by naked eye, typically in the far field of strong earthquakes. Anomalous waves are perceived by all people on small boats, few people on larger boats, most people on the coast. Water in swimming pools swings and may sometimes overflows. c) Hair-thin cracks (millimeter-wide) might be occasionally seen where lithology (e.g., loose alluvial deposits, saturated soils) and/or morphology (slopes or ridge crests) are most prone to this phenomenon. d)Exceptionally, rocks may fall and small landslide may be (re)activated, along slopes where the equilibrium is already near the limit state, e.g. steep slopes and cuts, with loose and generally saturated soil. e) Tree limbs shake feebly. V - STRONG - Marginal effects in the environment Primary effects are absent. Secondary effects: a) Rare variations of the water level in wells and/or of the flow-rate of springs are locally recorded, as well as small variations of chemical-physical properties of water and turbidity in lakes, springs and wells. b) In closed basins (lakes, even seas) seiches with height of decimeters may develop, sometimes noted also by naked eye, typically in the far field of strong earthquakes. Anomalous waves up to several tens of cm high are perceived by all people on boats and on the coast. Water in swimming pools overflows. c) Thin cracks (millimeter-wide and several cms up to one meter long) are locally seen where lithology (e.g., loose alluvial deposits, saturated soils) and/or morphology (slopes or ridge crests) are most prone to this phenomenon. d) Rare small rockfalls, rotational landslides and slump earth flows may take place, along often but not necessarily steep slopes where equilibrium is near the limit state, mainly loose deposits and saturated soil. Underwater landslides may be triggered, which can induce small anomalous waves in coastal areas of sea and lakes. e) Tree limbs and bushes shake slightly, very rare cases of fallen dead limbs and ripe fruit. f) Extremely rare cases are reported of liquefaction (sand boil), small in size and in areas most prone to this phenomenon (highly susceptible, recent, alluvial and coastal deposits, near-surface water table). 10 MICHETTI A.M. ET ALII VI - SLIGHTLY DAMAGING - Modest effects in the environment Primary effects are absent. Secondary effects: a) Significant variations of the water level in wells and/or of the flow-rate of springs are locally recorded, as well as small variations of chemical-physical properties of water and turbidity in lakes, springs and wells. b) Anomalous waves up to many tens of cm high flood very limited areas nearshore. Water in swimming pools and small ponds and basins overflows. c) Occasionally, millimeter-centimeter wide and up to several meters long fractures are observed in loose alluvial deposits and/or saturated soils; along steep slopes or riverbanks they can be 1-2 cm wide. A few minor cracks develop in paved (either asphalt or stone) roads. d) Rockfalls and landslides with volume reaching ca. 103 m3 can take place, especially where equilibrium is near the limit state, e.g. steep slopes and cuts, with loose saturated soil, or highly weathered / fractured rocks. Underwater landslides can be triggered, occasionally provoking small anomalous waves in coastal areas of sea and lakes, commonly seen by intrumental records. e) Trees and bushes shake moderately to strongly; a very few tree tops and unstable-dead limbs may break and fall, also depending on species, fruit load and state of health. f) Rare cases are reported of liquefaction (sand boil), small in size and in areas most prone to this phenomenon (highly susceptible, recent, alluvial and coastal deposits, near surface water table). VII - DAMAGING - Appreciable effects in the environment Primary effects: observed very rarely, and almost exclusively in volcanic areas. Limited surface fault ruptures, tens to hundreds of meters long and with centimetric offset, may occur, essentially associated to very shallow earthquakes. Secondary effects: The total affected area is in the order of 10 km2. a) Significant temporary variations of the water level in wells and/or of the flow-rate of springs are locally recorded. Seldom, small springs may temporarily run dry or appear. Weak variations of chemical-physical properties of water and turbidity in lakes, springs and wells are locally observed. b) Anomalous waves even higher than a meter may flood limited nearshore areas and damage or wash away objects of variable size. Water overflows from small basins and watercourses. c) Fractures up to 5-10 cm wide and up to hundred metres long are observed, commonly in loose alluvial deposits and/or saturated soils; rarely, in dry sand, sand-clay, and clay soil fractures are also seen, up to 1 cm wide. Centimeter-wide cracks are common in paved (asphalt or stone) roads. d) Scattered landslides occur in prone areas, where equilibrium is unstable (steep slopes of loose / saturated soils), while modest rock falls are common on steep gorges, cliffs). Their size is sometimes significant (103 - 105 m3); in dry sand, sand-clay, and clay soil, the volumes are usually up to 100 m3. Ruptures, slides and falls may affect riverbanks and artificial embankments and excavations (e.g., road cuts, quarries) in loose sediment or weathered / fractured rock. Significant underwater landslides can be triggered, provoking anomalous waves in coastal areas of sea and lakes, directly felt by people on boats and ports. e) Trees and bushes shake vigorously; especially in densely forested areas, many limbs and tops break and fall. f) Rare cases are reported of liquefaction, with sand boils up to 50 cm in diameter, in areas most prone to this phenomenon (highly susceptible, recent, alluvial and coastal deposits, near surface water table). VIII - HEAVILY DAMAGING - Extensive effects in the environment Primary effects: observed rarely. Ground ruptures (surface faulting) may develop, up to several hundred meters long, with offsets not exceeding a few cm, particularly for very shallow focus earthquakes such as those common in volcanic areas. Tectonic subsidence or uplift of the ground surface with maximum values on the order of a few centimeters may occur. INTENSITY SCALE ESI 2007 11 Secondary effects: The total affected area is in the order of 100 km2. a) Springs may change, generally temporarily, their flow-rate and/or elevation of outcrop. Some small springs may even run dry. Variations in water level are observed in wells. Weak variations of chemical-physical properties of water, most commonly temperature, may be observed in springs and/or wells. Water turbidity may appear in closed basins, rivers, wells and springs. Gas emissions, often sulphureous, are locally observed. b) Anomalous waves up to 1-2 meters high flood nearshore areas and may damage or wash away objects of variable size. Erosion and dumping of waste is observed along the beaches, where some bushes and even small weak-rooted trees can be eradicated and drifted away. Water violently overflows from small basins and watercourses. c) Fractures up to 50 cm wide and up to hundreds metres long, are commonly observed in loose alluvial deposits and/or saturated soils; in rare cases fractures up to 1 cm can be observed in competent dry rocks. Decimetric cracks arecommon in paved (asphalt or stone) roads, as well as small pressure undulations. d) Small to moderate (103 - 105 m3) landslides are widespread in prone areas; rarely they can occur also on gentle slopes; where equilibrium is unstable (steep slopes of loose / saturated soils; rock falls on steep gorges, coastal cliffs) their size is sometimes large (105 - 106 m3). Landslides can occasionally dam narrow valleys causing temporary or even permanent lakes. Ruptures, slides and falls affect riverbanks and artificial embankments and excavations (e.g., road cuts, quarries) in loose sediment or weathered / fractured rock. Frequent is the occurrence of landslides under the sea level in coastal areas. e) Trees shake vigorously; branches may break and fall, trees may be uprooted , especially along steep slopes. f) Liquefaction may be frequent in the epicentral area, depending on local conditions; the most typicalò effects are: sand boils up to ca. 1 m in diameter; apparent water fountains in still waters; localised lateral spreading and settlements (subsidence up to ca. 30 cm), with fissuring parallel to waterfront areas (river banks, lakes, canals, seashores). g) In dry areas, dust clouds may rise from the ground in the epicentral area. h) Stones and even small boulders and tree trunks may be thrown in the air, leaving typical imprints in soft soil. IX - DESTRUCTIVE - Effects in the environment are a widespread source of considerable hazard and become important for intensity assessment Primary effects: observed commonly. Ground ruptures (surface faulting) develop, up to a few km long, with offsets generally in the order of several cm. Tectonic subsidence or uplift of the ground surface with maximum values in the order of a few decimeters may occur. Secondary effects: The total affected area is in the order of 1000 km2. a) Springs can change, generally temporarily, their flow-rate and/or location to a considerable extent. Some modest springs may even run dry. Temporary variations of water level are commonly observed in wells. Variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Water turbidity is common in closed basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. b) Meters high waves develop in still and running waters. In flood plains water streams may even change their course, also because of land subsidence. Small basins may appear or be emptied. Depending on shape of sea bottom and coastline, dangerous tsunamis may reach the shores with runups of up to several meters flooding wide areas. Widespread erosion and dumping of waste is observed along the beaches, where bushes and trees can be eradicated and drifted away. c) Fractures up to 100 cm wide and up to hundreds metres long are commonly observed in loose alluvial deposits and/or saturated soils; in competent rocks they can reach up to 10 cm. Significant cracks are common in paved (asphalt or stone) roads, as well as small pressure undulations. d) Landsliding is widespread in prone areas, also on gentle slopes; where equilibrium is unstable (steep slopes of loose / saturated soils; rock falls on steep gorges, coastal cliffs) their size is frequently large (105 m3), sometimes very large (106 m3). Landslides can dam narrow valleys causing temporary or even permanent lakes. Riverbanks, artificial embankments and excavations (e.g., road cuts, quarries) frequently collapse. Frequent are large landslides under the sea level. e) Trees shake vigorously; branches and thin tree trunks frequently break and fall. Some trees might be uprooted and fall, especially along steep slopes. f) Liquefaction and water upsurge are frequent; the most typical effects are: sand boils up to 3 m in diameter; apparent water fountains in still waters; frequent lateral spreading and settlements (subsidence of more than ca. 30 cm), with fissuring parallel to waterfront areas (river banks, lakes, canals, seashores). 12 MICHETTI A.M. ET ALII g) In dry areas, dust clouds may rise from the ground. h) Small boulders and tree trunks may be thrown in the air and move away from their site for meters, also depending on slope angle and roundness, leaving typical imprints in soft soil. X - VERY DESTRUCTIVE - Effects on the environment become a leading source of hazard and are critical for intensity assessment Primary effects become leading. Surface faulting can extend for few tens of km, with offsets from tens of cm up to a few meters. Gravity grabens and elongated depressions develop; for very shallow focus earthquakes in volcanic areas rupture lengths might be much lower. Tectonic subsidence or uplift of the ground surface with maximum values in the order of few meters may occur. Secondary effects. The total affected area is in the order of 5,000 km2. a) Many springs significantly change their flow-rate and/or elevation of outcrop. Some springs may run temporarily or even permanently dry. Temporary variations of water level are commonly observed in wells. Even strong variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Often water becomes very muddy in even large basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. b) Meters high waves develop in even big lakes and rivers, which overflow from their beds. In flood plains rivers may change their course, temporary or even permanently, also because of widespread land subsidence. Basins may appear or be emptied. Depending on shape of sea bottom and coastline, tsunamis may reach the shores with runups exceeding 5 m flooding flat areas for thousands of meters inland. Small boulders can be dragged for many meters. Widespread deep erosion is observed along the shores, with noteworthy changes of the coastline profile. Trees nearshore are eradicated and drifted away. c) Open ground cracks up to more than 1 m wide and up to hundred metres long are frequent, mainly in loose alluvial deposits and/or saturated soils; in competent rocks opening reaches several decimeters. Wide cracks develop in paved (asphalt or stone) roads, as well as pressure undulations. d) Large landslides and rock-falls (> 105 - 106 m3) are frequent, practically regardless of equilibrium state of slopes, causing temporary or permanent barrier lakes. River banks, artificial embankments, and sides of excavations typically collapse. Levees and earth dams may also incur serious damage. Frequent are large landslides under the sea level in coastal areas. e) Trees shake vigorously; many branches and tree trunks break and fall. Some trees might be uprooted and fall. f) Liquefaction, with water upsurge and soil compaction, may change the aspect of wide zones; sand volcanoes even more than 6 m in diameter; vertical subsidence even > 1m; large and long fissures due to lateral spreading are common. g) In dry areas, dust clouds commonly rise from the ground. h) Boulders (diameter in excess of 2-3 meters) can be thrown in the air and move away from their site for hundreds of meters down even gentle slopes, leaving typical imprints in soil. XI - DEVASTATING - Effects on the environment become decisive for intensity assessment, due to saturation of structural damage Primary effects are dominant Surface faulting extends from several tens of km up to more than one hundred km, accompanied by slips reaching several meters. Gravity graben, elongated depressions and pressure ridges develop. Drainage lines can be seriously offset. Tectonic subsidence or uplift of the ground surface with maximum values in the order of numerous meters may occur. Secondary effects. The total affected area is in the order of 10,000 km2. a) Many springs significantly change their flow-rate and/or elevation of outcrop. Many springs may run temporarily or even permanently dry. Temporary or permanent variations of water level are generally observed in wells. Even strong variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Often water becomes very muddy in even large basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. b) Large waves develop in big lakes and rivers, which overflow from their beds. In flood plains rivers can change their cour- INTENSITY SCALE ESI 2007 13 se, temporary or even permanently, also because of widespread land subsidence and landsliding. Basins may appear or be emptied. Depending on shape of sea bottom and coastline, tsunamis may reach the shores with runups reaching 15 meters and more devastating flat areas for kilometers inland. Even meter-sized boulders can be dragged for long distances. Widespread deep erosion is observed along the shores, with noteworthy changes of the coastal morphology. Trees nearshore are eradicated and drifted away. c) Open ground cracks up to several meters wide are very frequent, mainly in loose alluvial deposits and/or saturated soils. In competent rocks they can reach 1 m. Very wide cracks develop in paved (asphalt or stone) roads, as well as large pressure undulations. d) Large landslides and rock-falls (> 105 - 106 m3) are frequent, practically regardless of equilibrium state of slopes, causing many temporary or permanent barrier lakes. River banks, artificial embankments, and sides of excavations typically collapse. Levees and earth dams incur serious damage. Significant landslides can occur even at 200 - 300 km distance from the epicenter. Frequent are large landslides under the sea level in coastal areas. e) Trees shake vigorously; many branches and tree trunks break and fall. Many trees are uprooted and fall. f) Liquefaction changes the aspect of extensive zones of lowland, determining vertical subsidence possibly exceeding several meters; numerous large sand volcanoes, and severe lateral spreading can be observed. g) In dry areas dust clouds arise from the ground. h) Big boulders (diameter of several meters) can be thrown in the air and move away from their site for long distances down even gentle slopes., leaving typical imprints in soil. XII - COMPLETELY DEVASTATING - Effects in the environment are the only tool for intensity assessment Primary effects are dominant. Surface faulting is at least few hundreds of km long, accompanied by offsets reaching several tens of meters. Gravity graben, elongated depressions and pressure ridges develop. Drainage lines can be seriously offset. Landscape and geomorphological changes induced by primary effects can attain extraordinary extent and size (typical examples are the uplift or subsidence of coastlines by several meters, appearance or disappearance from sight of significant landscape elements, rivers changing course, origination of waterfalls, formation or disappearance of lakes). Secondary effects. The total affected area is in the order of 50,000 km2 and more. a) Many springs significantly change their flow-rate and/or elevation of outcrop. Temporary or permanent variations of water level are generally observed in wells. Many springs and wells may run temporarily or even permanently dry. Strong variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Water becomes very muddy in even large basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. b) Giant waves develop in lakes and rivers, which overflow from their beds. In flood plains rivers change their course and even their flow direction, temporary or even permanently, also because of widespread land subsidence and landsliding. Large basins may appear or be emptied. Depending on shape of sea bottom and coastline, tsunamis may reach the shores with runups of several tens of meters devastating flat areas for many kilometers inland. Big boulders can be dragged for long distances. Widespread deep erosion is observed along the shores, with outstanding changes of the coastal morphology. Many trees are eradicated and drifted away. All boats are tore from their moorings and swept away or carried onshore even for long distances. All people outdoor are swept away. c) Ground open cracks are very frequent, up to one meter or more wide in the bedrock, up to more than 10 m wide in loose alluvial deposits and/or saturated soils. These may extend up to several kilometers. d) Large landslides and rock-falls (> 105 - 106 m3) are frequent, practically regardless to equilibriumstate of the slopes, causing many temporary or permanent barrier lakes. River banks, artificial embankments, and sides of excavations typically collapse. Levees and earth dams incur serious damage. Significant landslides can occur at more than 200 - 300 km distance from the epicenter. Frequent are very large landslides under the sea level in coastal areas. e) Trees shake vigorously; many branches and tree trunks break and fall. Many trees are uprooted and fall. f) Liquefaction occurs over large areas and changes the morphology of extensive flat zones, determining vertical subsidence exceeding several meters, widespread large sand volcanoes, and extensive severe lateral spreading can be observed. g) In dry areas dust clouds arise from the ground. h) Also very big boulders can be thrown in the air and move for long distances even down very gentle slopes, leaving typical imprints in soil. Guidelines Linee Guida 1. - BACKGROUND 1.1. - RATIONALE The twelve degrees macroseismic intensity scales, developed since the beginning of XX century, were based on evaluation of the effects on a) humans, b) manmade structures and c) natural environment (fig. 1). When the first models of macroseismic scales appeared, the Authors intuitively followed the inspired idea of including different types of effects, or effects on different kinds of “receivers”. Without giving a formal definition of this successful methodological approach, DE ROSSI, MERCALLI, CANCANI, OMORI, SIEBERG and their colleagues incorporated in the macroseismic scales effects on humans, on buildings and on natu- effects on humans effects on manmade structures Intensity (I) effects on natural environment Fig. 1 - According to the original definition of intensity in the twelve degrees scales, i.e., the Mercalli-Cancani-Sieberg Scale (MCS), the Modified Mercalli scale (MM-31 and MM-56) and the MedvedevSponheuer-Karnik scale (MSK-64), the assessment of intensity degrees has to be based on humans, manmade structures and natural environment. - Secondo la defnizione originale di intensità nelle scale a dodici gradi, quali la scala Mercalli-Cancani-Sieberg (MCS), la scala Mercalli Modificata (MM-31 e MM - 56) e la scala Medvedev-Sponheuer-Karnik (MSK 64), la valutazione del grado di intensità deve essere basata sugli effetti sull’uomo, sulle strutture antropiche e sull’ambiente naturale. re. In this way, the effects produced by earthquakes at the surface have notably come under close scrutiny, recognizing the fact that they actually result from the cumulated effects of the source (vibrations generated during slip, finite deformations), of the propagation of seismic waves, and, lastly, of local site effects. Later it became clear that by doing this they were able to take into account the whole frequency range of interest, including its static component. Therefore, according to this original and valuable approach, Intensity can be defined as a classification of effects, which allows measuring the earthquake severity in the whole range of frequencies including static deformations and vibrational effects. However, in the early versions of the twelve degrees scales (cf. DAVISON, 1921), the effects of the earthquakes on the natural environment were scarcely documented. Their presence in the scale was mostly due to the many references to ground cracks, landslides, and landscape modifications, contained in the historical sources. Later, in the second half of the XX century, these effects have been increasingly disregarded in the literature and in the practice of macroseismic investigation, probably due to their inner complexity and variability requiring specific skills and knowledge, while increasing attention has been paid to the apparently easier to analyze effects on humans and manmade structures (e.g., ESPINOSA et alii, 1976a; 1976b; GRUNTHAL, 1998). In fact, recent studies (DENGLER & MCPHERSON, 1993; SERVA, 1994, DOWRICK, 1996; ESPOSITO et alii, 1997; HANCOX et alii, 2002; MICHETTI et alii, 2004; and references therein) have offered new substantial evidence that coseismic environmental effects provide precious information on the ear- 16 MICHETTI A.M. ET ALII thquake size and its intensity field, complementing, de facto, the traditional damage-based macroseismic scales. As a matter of fact, with the outstanding growth of Paleoseismology as a new independent discipline, nowadays the effects on the environment can be described and quantified with a remarkable detail compared with that available at the time of the earlier scales. Therefore, today the definition of the intensity degrees can effectively take advantage of the diagnostic characteristics of the effects on natural environment. This is the goal of the ESI 2007 scale. Its use, alone or integrated with the other traditional scales (see chapter 2), affords a better picture of the earthquake scenario, because only environmental effects allow suitable comparison of the earthquake intensity both: · in time: effects on the natural environment are comparable for a time-window (recent, historic and palaeo seismic events) much larger than the period of instrumental record (last century), and · in different geographic areas: environmental effects do not depend on peculiar socio-economic conditions or different building practices. 1.2. - PRIMARY AND SECONDARY EFFECTS Earthquake Environmental Effects (EEEs) are any phenomena generated in the natural environment by a seismic event. They can be categorized in two main types: · primary effects, the surface expression of the seismogenic tectonic source (including surface faulting, surface uplift and subsidence), typically observed for crustal earthquakes over a certain threshold value of magnitude. Being directly linked to the size, hence the energy of the earthquake, these effects in principle do not suffer saturation, i.e., they saturate only for intensity XII, this being an obvious inherent limit of all macroseismic scales. · secondary effects: phenomena generally induced by the ground shaking. Their occurrence is commonly observed in a specific range of intensities. For each type of secondary effect, the ESI 2007 scale describes their characteristics and size as a diagnostic feature in a range of intensity degrees. Hence, in some cases it is only possible to establish a minimum intensity value. Conversely, the total area of distribution of secondary effects does not saturate and therefore it can be used as an independent tool for the assessment of the epicentral intensity Ι0 (par. 3.2). 1.3. - THRESHOLD FOR SURFACE FAULTING IN VOLCANIC AREAS The focal depth and the stress environment of an earthquake obviously influence the occurrence and the size of the observed effects. Two crustal earthquakes with the same energy but very different focal depths and stress environment can produce a very different field of environmental effects and therefore largely different local intensity values. This is particularly important in volcanic areas, where tectonic earthquakes with low magnitude and very shallow focus (in the order of 1-4 km) can generate primary effects (e.g., AZZARO, 1999). To take this into account, the threshold for surface faulting in volcanic areas has been set at intensity VII, whereas for typical earthquakes (focal depth 5-15 km) primary effects start from intensity VIII. 2. - HOW TO USE THE ESI 2007 SCALE When suitable EEEs are documented, the ESI 2007 scale allows independent estimates of epicentral and local intensity. Through a straightforward procedure (fig. 2) these values can be used for intensity assessment alone or together with damage-based traditional scales to produce a “hybrid” intensity field. The use of the ESI 2007 scale as an independent tool is recommended when (case A in fig. 2) only environmental effects are diagnostic because effects on humans and on manmade structures are absent, or too scarce (i.e. in sparsely populated or desert areas), or suffer saturation (i.e., for intensity X to XII). As shown by the processing of many earthquakes worldwide, typically the ESI 2007 used alone can define the intensity degree with an acceptable level of accuracy starting from intensity VII, when environmental effects usually become diagnostic. This accuracy improves in the higher degrees of the scale, in particular in the range of occurrence of primary effects, typically starting from intensity VIII, and with growing resolution for intensity IX, X, XI and XII. Obviously, when environmental effects are not available, intensity has to be assessed by damagebased traditional scales (case B). If effects are available either on manmade structures and natural environments (case C), allowing to estimate two independent intensities, in general the intensity has to coincide with the highest value between these two estimates. Of course, expert judgment is an essential component in the process of comparing intensitiy asses- 17 INTENSITY SCALE ESI 2007 sed using different categories of “receivers”. This procedure allows generating a “hybrid field” of local intensities, i.e., derived from the integration of ESI 2007 and other intensity scales. This is deemed to be the best intensity scenario because 1) it takes into account all the effects triggered by the earthquake, 2) it is in agreement with the original definition of intensity, and 3) it allows the comparison of earthquakes in time and in space over the largest chronological and geographic window. the epicenter. Several techniques can be applied to assess I0; for instance, POSTPISCHL (1985) define I0 as “the value of the closed isoseismal line having the highest degree and including at least 3 different data points”. Surface faulting parameters and total area of distribution of secondary effects (landslides and/or liquefactions) are two independent tools to assess I0 on the basis of environmental effects, starting from the intensity VII. SURFACE FAULTING PARAMETERS: The ranges reported in Table 1 are based on the analysis of surface faulting parameters and intensity data available for more than 400 shallow crustal earthquakes worldwide (SURFIN, SURFace faulting and INtensity database; INQUA scale Project, 2007). The use of this simple table for I0 assessment requires particular attention when the amount of surface faulting is close to the boundaries between two intensity degrees. In this case it is recommended to choose the intensity value better consistent with the characteristics and distribution of secondary effects. 2.1. - PROCEDURE TO USE THE ESI 2007 SCALE AS A SELF INSTRUMENT FOR INTENSITY ASSESSMENT Evidently the ESI 2007 scale is a tool to assess both epicentral and local intensities. 2.1.1. - Epicentral intensity (Ι0) Epicentral intensity (I0) is defined as the intensity of shaking at epicenter, i.e. what intensity we would get, if there were a locality that matches DATA COLLECTION HISTORICAL EARTHQUAKES INTENSITY ASSESSMENT A NATURAL ENVIRONMENT Revision of effects from historical documents IESI B RECENT EARTHQUAKES Revision of effects from macroseismic and geological surveys AVAILABLE EFFECTS ON C FUTURE EARTHQUAKES Ad hoc macroseismic and geological field surveys HUMANS + MANMADE STRUCTURES AN D NATURAL ENVIRONMENT HUMANS + MANMADE STRUCTURES IMCS IMM IMSK IEMS IJMA IESI IMCS IMM IMSK IEMS IJMA MAXIMUM VALUE = INTENSITY Fig. 2 - Logical scheme for the use of ESI 2007 scale alone or together with damage-based traditional scales. We show only the most commonly used scales, however, any scale can be integrated with the ESI 2007 scale following the same methodological steps. - Schema logico per l'utilizzo della scala ESI 2007 da sola o insieme con le scale tradizionali basate sui danni. Qui sono considerate solo le scale maggiormente usate, tuttavia qualsiasi scala può integrarsi con la scala ESI 2007 seguendo un approccio metodologico analogo. 18 MICHETTI A.M. ET ALII TOTAL AREA OF SECONDARY EFFECTS: Starting from intensity VII, the ESI 2007 scale considers the total area of secondary effects as diagnostic element for I0 assessment. Even in this case, for each intensity degree table 1 only lists the order of magnitude of the total area, and the chosen value of I0 has to be consistent with primary effects. The definition of total area should not include the isolated effects occasionally located in the far field. In fact, the occurrence of these effects is most likely due to peculiar site conditions. Evidently, only a sound professional judgment can establish which effects should be included/excluded in the definition of total area. TAB. 1 - Ranges of surface faulting parameters (primary effects) and typical extents of total area (secondary effects) for each intensity degree. - Valori di riferimento per ciascun grado di intensità relativo ai parametri di fagliazione superficiale (effetti primari) e all’area totale degli effetti secondari. I0 Intensity IV V VI VII VIII IX X XI XII PRIMARY EFFECTS SURFACE RUPTURE LENGTH SECONDARY EFFECTS MAX SURFACE DISPLACEMENT / DEFORMATION TOTAL AREA (*) Centimetric 10 km2 100 km2 5 - 40 cm 40 - 300 cm 300 –700 cm > 700 cm 1000 km2 5000 km2 10000 km2 > 50000 km2 (*) Several hundreds meters 1- 10 km 10 - 60 km 60 – 150 km > 150 km (*) Limited surface fault ruptures, tens to hundreds meters long with centimetric offset may occur essentially associated to very shallow earthquakes in volcanic areas. 2.1.2 . - Local intensity (IL) The local intensity is essentially assessed through the description of secondary effects. However, even the local expression of primary effects, in terms of maximum displacement of a fault segment, may contribute to its evaluation. The evaluation of local intensity can be done in two different ways: LOCALITY - SITE: this approach is recommended when the descriptions of environmental effects are not homogeneously surveyed over the territory, which is common for historical earthquakes. The main advantage of this procedure is that it allows the comparison with local intensities deriving from traditional macroseismic scales. According to this approach, a Site can be defined as any place where a single environmental effect has occurred. The description of one effect has to be done at this level. One Locality may include several sites and presents a level of generalization, to which intensity can be assigned. It can refer to any place, either inhabited or natural. It has to be small enough to keep separated areas with significantly different site intensities, but large enough to include several sites and consequently to be representative for intensity assessment. Therefore, the locality has to be defined by expert judgment. REGULAR GRID: in case a systematic field survey of the affected area provides a homogeneous distribution of environmental effects, which is still uncommon for modern earthquakes but highly advisable for future earthquakes, it is recommended to divide the territory into a regular grid with a cell size that depends on the scale of the field survey. It should be possible to assign a local intensity to each cell. The resulting distribution of local intensities allows to define the map of isoseismals. However, with this approach the comparison and integration with “standard” macroseismic intensity values may become quite difficult. 2.2. - CORRELATION BETWEEN ESI 2007 AND TRADITIONAL MACROSEISMIC SCALES In principle, the correlations of intensity scales, degree by degree, should be never allowed because each scale classifies the effects in a different way. Hence, for the comparison of two earthquakes it should be advisable to use the same intensity scale, even if it is necessary to reclassify all the effects. For instance, in the MSK64 scale the concepts of “typical” damage and building types are used. As a result this is a scale of constant intervals. The MCS and Modified Mercalli scales, based on maximum effects, are scales of order. As a consequence intensity VIII is much easier to get in original Mercalli than applying MSK64. Indeed, the “classic” twelve degrees scales, though they included environmental effects, were not able to differentiate intensities above IX, because (a) they did not make difference between primary and secondary effects, (b) they did not use quantitative approach for the effects on nature. Therefore, it is expected that when we deal with the strongest earthquakes the application of the ESI 2007 scale will yield an intensity value that is different, and more physically meaningful, from that obtained with the others scales. That is exactly the reason why it is necessary to develop this new intensity scale. INTENSITY SCALE ESI 2007 As a matter of fact, in the practice of macroseismic investigation, very often one is obliged to compare earthquakes intensities classified with different scales. This has promoted the use of conversion tables, such as those proposed by KRINITZSKY & CHANG (1978), REITER (1990), and PANZA (2004). On the other hand, the application of such kind of tables has often caused the introduction of additional uncertainties, such as the use of half-degrees or fractional degrees. In order to avoid these inconveniences, the correlation among the most important intensity scales has to be simply based on one-to-one relationships. As discussed in MICHETTI et alii, (2004), due to the level of uncertainty inherent in the structure itself of the macroseismic scales, and in case a conversion between scales is a step that cannot be absolutely avoided, the best we can do is to consider all the twelve degrees scales as equivalent. This includes also the Chinese macroseismic intensity scale, which has been originally designed to be consistent with the MM scale (e.g., XIE, 1957; WANG, 2004). Nevertheless, the correlation with the 7-degrees JMA intensity scale (KRINTIZSKY & CHANG, 1977; REITER, 1990; HANCOX et alii, 2002), and with other scales not based on twelve degrees, inevitably requires grouping of some intensity degrees. 19 3.1. - MAIN GROUPS OF INTENSITY DEGREES The ESI 2007 scale starts where environmental effects become regularly observed in favorable conditions, i.e. at intensity IV. The scale is linear and works well up to XII degree. In the first version of the scale, intensity I, II and III were also defined using environmental effects (MICHETTI et alii, 2004). It is important to remark that several effects on nature, especially concerning water bodies and hydrogeological phenomena (MONTGOMERY & MANGA, 2003 and references therein), but also instrumentally-detected primary tectonic deformations (permanent fault offset measured at the INFN Gran Sasso, Italy, strainmeter; cf., AMORUSO & CRESCENTINI, 1999), have been observed for very low intensity. Perhaps future investigation will allow a new revision of the scale in order to include environmental effects suitable for intensity assessment in the range from I to III. However, after 4 years of application at a global scale through the INQUA scale project, it was clear that with the knowledge available today, effects on natural environment in this range are not diagnostic. Therefore, comparing the ESI 2007 with the other 12 degrees scales, we can identify three main subset: I) From I to III: There are no environmental effects that can be used as diagnostic. 3. - STRUCTURE OF THE SCALE The ESI 2007 scale has been developed to be consistent with the Modified Mercalli macroseismic scale (MM-31, WOOD & NEUMANN, 1931; MM-56, RICHTER, 1958) and the MSK-64 ( Medvedev-Sponheuer-Karnik scale), since these are the most applied worldwide and includes many explicit references to environmental effects. More in general, the new scale was carefully designed in order to keep the internal consistency of the original twelve degrees scale, as discussed in depth by MICHETTI et alii, (2004). A great deal of work in seismic hazard assessment is accomplished in the world, and intensity is a basic parameter in this. Any “new word” in this research field must not result in dramatic changes. The members of the WG are aware that, by definition, the twelve-degree macroseismic scales are based essentially on effects on humans in the range of intensity II to V, on damage in the range of intensity VI to IX, and on natural environment in the range of intensity X to XII. The ESI 2007 scale is therefore really useful only for the assessment of the highest intensities. But, as mentioned above, to avoid any confusion, the classical numbering is kept. II) From IV to IX: Environmental effects are easily observable starting from intensity IV, and often permanent and diagnostic especially starting from intensity VII. However, they are necessarily less suitable for intensity assessment than effects on humans and manmade structures. Their use is therefore recommended especially in sparsely populated areas; III) From X to XII: Effects on humans and manmade structures saturate, while environmental effects become dominant; in fact, several types of environmental effects do not suffer saturation in this range. Thus, environmental effects are the most effective tool to evaluate the intensity. 3.2. - TITLE AND DESCRIPTION The title reflects the corresponding force of the earthquake and the role of environmental effects. In the description, the characteristics and size of primary effects associated to each degree are reported firstly. Then, secondary effects are described i) in terms of total area of distribution for the assessment of epicentral Intensity (star- 20 MICHETTI A.M. ET ALII ting from intensity VII); ii) grouped in several categories (see previous chapter and tab. 2), ordered by the initial degree of occurrence. Text in Italic has been used to highlight descriptions regarded as diagnostic by itself for a given degree. 3.3. - DESCRIPTION OF EARTHQUAKE ENVIRONMENTAL EFFECTS It is possible to collect the characteristics of earthquake environmental effects in two different ways: - the ESI 2007 Form, designed to be used during the emergency phase after an earthquake (Appendix II); - the EEE Database, designed to be used for the revision of historical reports and for final archiving. Both these documents can be downloaded from h t t p : / / w w w. a p a t . g o v. i t / s i t e / e n GB/Projects/INQUA_Scale/Documents/ The structure of the ESI 2007 Form and EEE Database is similar. Thus, it is possible to migrate from the former to the latter without difficulties. 3.3.1. - Primary effects The size of primary effects is typically expressed in terms of two parameters: i) Total Surface Rupture Length (SRL) and ii) Maximum Displacement (MD). Their occurrence is commonly associated to a minimum intensity value (VIII), except in case of very shallow earthquakes in volcanic areas. Amount of tectonic surface deformation (uplift, subsidence) is also taken into account. 3.3.2. - Secondary effects Secondary effects can be classified into eight main categories (tab. 2). While some descriptions are considered diagnostic (in Italic), others are susceptible to be changed after the implementation of the database which correlates characteristic features of secondary effects and intensity degrees. Nevertheless, in order to provide a reasonable value for the total area of secondary effects, it is recommended to describe and map the whole distribution of secondary effects, including those not yet incorporated in the description of intensity degrees (e.g., karst collapses). A - Hydrological anomalies Hydrological anomalies show up from intensity III and saturate (i.e. their size does not increase) at intensity X. They can be divided in two groups: · Surface water effects: 1) Overflow; 2) Discharge variation; 3) Turbidity of rivers; · Ground water effects: 1) Drying up of springs; 2) Appearance of springs; 3) Temperature changes; 4) Anomaly in chemical component; 5) Turbidity of springs. Further useful information might be: the amount and rates of variation in temperature and discharge, the presence of anomalous chemical element, the duration of the anomaly, and the time delay. B - Anomalous waves/tsunamis In this category are included: seiches in closed basins, outpouring of water from pools and basins, and tsunami waves. In the case of tsunamis, more than the size of the tsunami wave itself, the effects on the shores (especially runup, beach erosion, change of coastal morphology), without TAB. 2 - Diagnostic range of intensity degrees for each class of environmental effects. - Intervallo di gradi di intensità diagnostico per ciascuna classe di effetti ambientali. Environmental effects SURFACE FAULTING AND DEFORMATION Diagnostic range of intensity degrees VIII (*) XII A HYDROLOGICAL ANOMALIES IV X B ANOMALOUS WAVES/TSUNAMIS IV XII C GROUND CRACKS IV X D SLOPE MOVEMENTS IV X E TREE SHAKING IV XI F LIQUEFACTIONS V X G DUST CLOUDS VIII VIII H JUMPING STONES IX XII (*) For intensity degree VII, limited surface fault ruptures, tens to hundreds meters long with centimetric offset may occur essentially associated to very shallow earthquakes in volcanic areas. INTENSITY SCALE ESI 2007 neglecting those on humans and manmade structures, are taken as diagnostic of the suffered intensity. Effects may already occur at intensity IV, but are more diagnostic from IX to XII. The definition of intensity degrees has taken advantage from the tsunami intensity scale proposed by PAPADOPOULOS & IMAMURA (2001), and from many descriptions of the aforementioned effects worldwide (e.g., LANDER et alii, 2003). C - Ground cracks Ground cracks show up from intensity IV and saturate (i.e. their size does not increase) at intensity X. Diagnostic parameters are lithology, strike and dip, maximum width, and area density. D - Slope movements Slope movements, including under water landslides, have been grouped in: 1) Rock fall; 2) Debris fall; 3) Toppling; 4) Rock slide; 5) Debris slide; 6) Avalanche; 7) Mudslide; 8) Debris flow; 9) Earth flow; 10) Mud flow; 11) Slow slide; 12) Slow earth flow; 13) Slow mud flow; 14) Lateral spread; 15) Sackung; 16) Complex (two or more concurrent types). They show up at intensity IV and saturate (i.e. their size does not increase) at intensity X. The total volume is diagnostic for intensity assessment. It can be roughly estimated on the basis of the landslide area when the depth of sliding mass can be reasonably estimated. The uncertainties introduced with this procedure do not appear to significantly influence the intensity evaluation. Further information: maximum dimension of blocks, area density, amount of slip, humidity and time delay. E - Trees’ shaking Trees’ shaking is reported from a minimum intensity IV. It is important to record the occurrence of broken branches and the morphologic characteristics of the area (flat, slope). The definition of intensity degrees basically follows these provided by DENGLER & MCPHERSON (1993). F - Liquefactions Liquefactions occur from intensity V. The diagnostic features for liquefactions are the diameter of sand volcanoes and the lithology. Saturation (i.e. their size does not increase) occur at intensity X. Other useful characteristics are shape, the time delay, the depth of water table and the occurrence of water and sand ejection. 21 G - Dust clouds Dust clouds are reported since intensity VIII, typically in dry areas. H - Jumping stones Jumping stones have been reported from minimum intensity IX. The size of stones and their imprint in soft soil are considered as diagnostic parameters for intensity evaluation. REFERENCES AMORUSO A. & CRESCENTINI L. (1999) - Coseismic and aseismic strain offsets recorded by the Gran Sasso Strainmeter. Phys.Chem. Earth (A), 24, 2, 101-104. AZZARO R. (1999) - Earthquake surface faulting at Mount Etna Volcano (Sicily) and implications for active tectonics. Journal of Geodynamics, 28 (2-3), 193 - 213. DAVISON, C. (1921). On scales of seismic intensity and on the construction of isoseismal lines. Bull. Seis. Soc.Am., 11, 95-129. DENGLER L. & MCPHERSON R. (1993) - The 17 August 1991 Honeydaw earthquake north coast California: a case for revising the Modified Mercalli Scale in sparsely populated areas. Bull. Seis. Soc. Am. 83, 4, 1081-1094. DOWRICK D. J. (1996) - The Modified Mercalli earthquake intensity scale- Revisions arising from recent studies of New Zealand earthquakes. Bull. Of new Zeal. Nat. Soc. For earthquake Engineering, 29, 2, 92-106. ESPINOSA, A. F., R. HUSID, S. T. ALGERMISSEN, & J. DE LAS CASAS (1976a) - TheLima earthquake of October 3, 1974, intensity distribution. Bulletin of the Seismological Society of America, 67, 1429-1440. ESPINOSA, A. F., R. HUSID, & A. QUESADA (1976b) -Intensity distribution and source parameters from field observations of the February 4, 1976, Guatemalan earthquake. In: “The Guatemalan Earthquake of February 4, 1976, a Preliminary Report”, A. F. ESPINOSA, Eds., U.S. Geological Survey Professional Paper 1002, 52-66 . ESPOSITO E., PORFIDO S., MASTROLORENZO G., NIKONOV A.A. & SERVA L., (1997) - Brief rewiew and preliminary proposal for the use of ground effects in the macroseismic intensity assesment. Proc. 30th International Geological Congress, Beijing, China, vol 5. Contemporary lithospheric motion seismic geology, the Netherlands, VSP ed., ISBN: 906764-269-X, 233-243. GRUNTHAL G. (1998) - European Macroseismic Scale 1998 (EMS-98). European Seismological Commission, Subcommission on Engineering Seismology, Working Group Macroseismic Scales. Conseil de l’Europe, Cahiers du Centre Européen de Géodynamique et de Séismologie, 15, Luxembourg, 99 pp. HANCOX G.T., PERRIN N.D. & DELLOW G.D. (2002) -Recent studies of historical earthquake-induced landsliding, ground damage, and MM intensity in New Zealand. Bulletin of the New Zealand Society for Earthquake Engineering, 35 (2), 59-95, ISSN 1174-9857. INQUA Scale Project (2007) - Available online at http: //www.apat.gov.it/site/en-GB/Projects/INQUA_Scale KRINITZSKY, E.L. & CHANG, F.K. (1988) - Intensity-related earthquake ground motions. Bulletin of the Association of Engineering Geologists, 25, 425-435. LANDER J.F., WHITESIDE L.S. & LOCKRIDGE P.A. (2003) Two Decades of Global Tsunamis 1982-2002. The International Journal of The Tsunami Society (21) 1, 22 MICHETTI A.M. ET ALII NOAA - NGDC, Boulder, Colorado USA, 73 pp. MICHETTI A.M., ESPOSITO E., GÜRPINAR J., MOHAMMADIOUN B., MOHAMMADIOUN A., PORFIDO S., ROGOZHIN E., SERVA L., TATEVOSSIAN R., VITTORI E., AUDEMARD F., COMERCI V., MARCO S., MCCALPIN J. & MÖRNER N.A. (2004) - The INQUA Scale. An innovative approach for asses sing earthquake intensities based on seismically-induced ground effects- in natural environment. Special paper APAT, Mem. Descr. Carta geol. d’Italia, 68. (E. VITTORI & V. COMERCI Eds.), 115 pp. MONTGOMERY D.R. & MANGA M. (2003) - Streamflow and Water Well Responses to Earthquakes. Science, 300, 27 June 2003, 2047-2049. PANZA G.F. (2004) - Correlation among intensity scales. Downloadable from http://www.apat.gov.it/ site/enGB/Projects/INQUA_Scale/Documents/, 15 p., Trieste. PAPADOPOULOS, G.A. & F. IMAMURA (2001) - Proposal for a new tsunami intensity scale. Proc. Internat. Tsunami Conference, Seattle , 7 - 9 August 2001, 569 - 577. POSTPISCHL D. (1985) - Catalogo dei terremoti italiani dall’anno 1000 al 1980. CNR-PFG 114, 2B: 238 pp. REITER L. (1990) - Earthquake Hazard Analysis. Issues and insights. Columbia University Press, New York, 254 pp. RICHTER C.F. (1958) - Elementary Seismology. W.H. FREEMAN & CO, San Francisco, 768 p. SERVA L. (1994) - Ground effects in intensity scales. Terra Nova 6, 414-416. WANG J. (2004) - Historical earthquake investigation and research in China. Annals of Geophysics, 47 (2/3), 831-838. XIE Y. (1957) - A new scale of seismic intensity adapted to the conditions in Chinese territories. Acta Geophysica Sinica, 6-1, 35-47, (in Chinese). V. COMERCI Eds.), 115 pp., Roma. MICHETTI A.M., LIVIO F., CHINGA K. ESPOSITO E., FANETTI D., GAMBILLARA R., MARTIN S., PASQUARÈ F., PORFIDO S., SILEO G. & VITTORI E. (2005) - Ground effects of the Ml 5.2, November 24, 2004, Salò earthquake, Northern Italy, and the seismic hazard of the western Southern Alps. Rend. Soc. Geol. It., 1 (2005), Nuova Serie, 134-135, 2 ff. PAPATHANASSIOU G., VALKANIOTIS S. & PAVLIDES S. (2007) - Applying the INQUA Scale to the Sofaeds 1954, Central Greece, earthquake. PORFIDO S., ESPOSITO E., VITTORI E., TRANFAGLIA G., GUERRIERI L. & PECE R. (2007) - Seismically induced ground effects of the 1805, 1930 and 1980 earthquakes in the Southern Apennines (Italy). Boll.Soc.Geol.It. (Ital .J. Geosci.), 126, No. 2, Roma. SALAMON A. (2005) - Seismically induced ground effects of the February 11, 2004, Ml=5.2 northeastern Dead Sea earthquake. Geological Survey of Israel, Report 30/04. SERVA L., ESPOSITO E., GUERRIERI L., PORFIDO S., VITTORI E. & COMERCI V. (in press) - Environmental Effects from some historical earthquakes in Southern Apennines (Italy) and macroseismic intensity asseessment. Contribution to INQUA EEE scale project. Quaternary International (2007), doi:10.1016/j.quaint.2007.03.015. SILVA P.G. (2006) - La Escala de Intensidad Macrosísmica de INQUA (EEE Intensity Scale): Efectos Geológicos y Geomorfológicos de los terremotos. Journal of Quaternary and Geomorphology: Cuaternario y Geomorfología, 20 (1.2). TATEVOSSIAN R.E. (in press) - The Verny, 1887, earthquake in central Asia: Application of the INQUA scale based on coseismic environmental effects. Quaternary International (2007), accepted manuscript. PUBLICATIONS WITHIN THE INQUA SCALE PROJECT In the frame of the “INQUA Scale Project” activities, numerous papers, reports and abstracts have been published. In this section is reported a preliminary list. ABSTRACTS PAPERS AND REPORTS (PUBLISHED OR IN PRESS). FOKAEFS A. & PAPADOPOULOS G. (in press) - Testing the new INQUA intensity scale in Greek earthquakes. Quaternary International (2007), doi: 10.1016/j.quaint.2007.02.019. GUERRIERI L., TATEVOSSIAN R., VITTORI E., COMERCI V., ESPOSITO E., MICHETTI A.M., PORFIDO S. & SERVA L. (2007) - Earthquake environmental effects (EEE) and intensity assessment: the INQUA scale project. Boll. Soc. Geol. It. (Ital. J. Geosci.), 126, No. 2, Roma. GUERRIERI L., VITTORI E., ESPOSITO E., PORFIDO S., TATEVOSSIAN R. & SERVA L. (2006) - The INQUA intensity scale. Brochure APAT, 4 pp., Roma. LALINDE C. P. & SANCHEZ J.A. (2007) - Earthquake and environmental effects in Colombia in the last 35 years. INQUA Scale Project. Bulletin of the Seismological Society of America, 97, (2), pp. 646-654. MICHETTI A.M., AUDEMARD F.A.M. & MARCO S. (2005) - Future trends in paleoseismology: Integrated study of the seismic landscape as a vital tool in seismic hazard analyses. Tectonophysics 408 (2005) 3 -21. MICHETTI A. M., ESPOSITO E., GÜRPINAR A., MOHAMMADIOUN J., MOHAMMADIOUN B., PORFIDO S., ROGOZHIN E., SERVA L., TATEVOSSIAN R., VITTORI E., AUDEMARD F., COMERCI V., MARCO S., MCCALPIN J. & MÖRNER N.A. (2004) - The INQUA Scale. An innovative approach for assessing earthquake intensities based on seismicallyinduced ground effects in natural environment. Special paper APAT, Mem. Descr. Carta Geol. d’Italia , 67. (E. VITTORI & 32nd International Geological Congress - Florence, Italy, 20-28 August 2004. MOHAMMADIOUN B. - Interpretation of paleoseismic data using an innovative macroseismicity scale. SERVA L., ESPOSITO E., GURPINAR A., MARCO S., MC CALPIN J., MICHETTI A.M., MOHAMMADIOUN B., PORFIDO S., TATEVOSSIAN R. & VITTORI E. - The INQUA Scale: an innovative approach for assessing earthquake base ond seismicallyinduced ground effects in natural environments. International Symposium on Active Faulting - Hokudan, Japan, 17-22 January 2005 ESPOSITO E., PORFIDO S., LIVIO F., MARTIN S., MICHETTI A. M., CHUNGA K., FANETTI D., GAMBILLARA, R., SILEO G. & VITTORI E. - Ground effects of the Ml 5.2, November 24, 2004, Salò earthquake, Northern Italy: a case study for the use of the INQUA scale. GUERRIERI L., COMERCI V. & VITTORI E. - An earthquakes database linking epicentral Intensity and surface faulting parameters. KINUGASA Y. - The INQUA Seismic Intensity Scale, its importance and problems. MICHETTI, A.M. - Paleoseismology, seismic hazard, and the INQUA Scale Project. PORFIDO S. & ESPOSITO E. - The INQUA Scale Project: Analysis and distribution of ground effects by type for Italian earthquakes. VITTORI E., GUERRIERI L. & COMERCI V. - Intensity - fault parameter relationships: implications for seismic hazard assessment. “Dark Nature - Rapid natural Change and Human Responses”, Como, Italy, 3-7 September, 2005 CHUNGA K., LEÓN C., QUIÑÓNEZ M., STALÍN BENÍTEZ & MONTENEGRO G. - Seismic Hazard Assessment for Guayaquil City (Ecuador): Insights from Quaternary Geological Data. INTENSITY SCALE ESI 2007 CHUNGA K., ZAMUDIO Y., MARÍN G., EGRED J., QUIÑÓNEZ M. & ITURRALDE D. - The 12 Dic, 1953, Earthquake, Ms 7.3, Ecuador-Peru border region: A Case Study for Applying the New INQUA Intensity Scale. ESPOSITO E., PORFIDO S, GUERRIERI L, VITTORI E. & PENNETTA M. - INQUA intensity Scale Evaluation for the 1980 Southern Italy “Historical” Earthquake. FOKAEFS A., G.A. PAPADOPOULOS & PAVLIDES S. - Testing the New INQUA Intensity Scale in Greek Earthquakes. GUERRIERI L., TATEVOSSIAN R., VITTORI E., COMERCI V., ESPOSITO E., MICHETTI A.M., PORFIDO S. & SERVA L. The Database of Coseismic Environmental Effects as a Tool for Earthquake Intensity Assessment within the INQUA EEE Scale Project. KAGAN E.J. , AGNON A., BAR-MATTHEWS M. & AVNER AYALON - Damaged Cave Deposits Record 200, 000 Years of Paleoseismicity: Dead Sea Transform Region. PAPATHANASSIOU G. & PAVLIDES S. - Using the INQUA Scale for the Assessment of Intensity: Case Study of 14/08/2003 Lefkada Earthquake, Greece. TATEVOSSIAN R. - Study of the Verny, 1887, Earthquake in Central Asia: Using Environmental Effects to Scale the Intensity ZAMUDIO DIAZ Y., MARIN RUIZ G. & VILCAPOMA LAZARO L. - Applying the INQUA Scale to Some Historical and Recent Peruvian Earthquakes. EGU General Assembly 2006, Vienna, Austria, 06 April 2006, Session “3000 years of earthquake ground effects reports in Europe: geological analysis of active faults and benefits for hazard assessment” AZUMA, T.& OTA, Y. - Comparison between seismic ground effects and instrumental seismic intensity- an example from a study on the 2004 Chuetsu earthquake in Central Japan. GIARDINA, F.,CARCANO C., LIVIO F.. MICHETTI, A.M., MUELLER, K., ROGLEDI S., SERVA L., SILEO G. & VITTORI E. - Active compressional tectonics and Quaternary capable faults in the Western Southern Alps. GUERRIERI L., ESPOSITO E., PORFIDO S. & VITTORI E. - The application of INQUA Scale to the 1805 Molise earthquake. MICHETTI A.M. - The INQUA Scale Project The INQUA Scale Project: linking pre-historical and historical records of earthquake ground effects. REICHERTER K.R., SILVA P.G., GOY J.L., SCHLEGEL U., SCHÖNEICH S. & ZAZO C. - Active faults and paleostress history of the Gibraltar Arc area (southern Spain) - first results. PAPANIKOLAOU I.D., PAPANIKOLAOU D.I., LEKKAS E.L. - Epicentral-near field and far field effects from recent earthquakes in Greece. Implications for the recently introduced INQUA Scale. SILVA BARROSO P.G., REICHERTER K., BARDAJÍ T., LARIO J., PELTZER M., GRÜTZNER C., BECKER-HEIDMANN P., GOY J.L., ZAZO C. & BORJA F. - The Baelo Claudia earthquake problem, Southern Spain. SILVA P., G.REICHERTER K.R., BARDAJÍ T., LARIO J., PELTZER M., GRÜTZNER CH., BECKER-HEIDMANN P., GOY J.L., ZAZO C.& BORJA F. - Surface and subsurface paleoseismic record of the Baelo Claudia area (Gibraltar Arc area, southern 23 Spain) - first results. ICTP IAEA Workshop on the Conduct of Seismic Hazard Analyses for Critical Facilities Trieste, Italy, 15-19 May 2006. ABDEL AZIZ M. - INQUA intensity assessment for the 1995 Aqaba earthquake. AMIT R. - The use of paleoseismic data and ground effects (INQUA Scale) of strong earthquakes for seismic hazard evaluations of the Dead Sea Rift. KINUGASA Y. - Use of geological data for seismic hazard assessment and siting of the nuclear facilities in Japan. LALINDE PULIDO C. - Active tectonics and earthquake ground effects in Colombia, with examples of applications of the INQUA Scale. MC CALPIN J. - Paleoseismology and Maximum Magnitude estimates in extensional terranes. MICHETTI A.M. - Introduction of the INQUA Intensity Scale. MOHAMMADIOUN B. - The INQUA Scale Project: A better link to dynamic source parameters and maximum magnitude determination. MUELLER K. - Assessing Mmax on Active Thrust Faults in New Madrid (USA) and the Northern Po Basin (Italy). NELSON A. - Earthquakes accompanied by tsunamis: their paleoseismic records and application to the INQUA intensity scale. OTA Y., AZUMA T. & LIN N. - Paleoseismological study and seismic hazards resulting from major recent active faulting in Japan and Taiwan, and examples of INQUA scale intensity maps. PAPATHANASIOU G. - Applications of the INQUA Scale in Greece. PORFIDO S., ESPOSITO E., GUERRIERI L.& VITTORI E. Application of the INQUA Scale to Italian earthquakes. REICHERTER K. - Paleoseismology and the study of earthquake ground effects in the Mediterranean Region. SERVA L. - The concept of the Intensity parameter in the Intensity scales. SILVA P.G. - Fault activity and earthquake ground effects in Spain: applications of the INQUA Scale in the Iberian Peninsula. TATEVOSSIAN R. - Geological effects in the macroseismic intensity assessment, and the application of the INQUA Scale in former USSR. VITTORI E. - Relationships among surface rupture parameters and intensity. OTHER CONFERENCES ASHOORI S., GHADYANI A., MEMARIAN H. & ZARÈ M. Estimation of the Earthquake Intensities in Iran based on ground effects (application of INQUA scale); two cases studies. LALINDE C.P., ESTRADA R. B.E. & FARBIARZ J. F. Preliminary application of the INQUA scale to the recent Colombian earthquakes. X° Congreso Colombiano de Geologia, Bogotà, April 2005. PAPATHANASSIOU G. & PAVLIDES S. - Lefkada. 14th MAEGS, Turin, September 2005. VITTORI E. - The INQUA EEE scale. WS Regional Cooperation on natural hazards: tools for risk management, Yerevan, Armenia, October 26-28, 2005. APPENDIX I Ear thquak e En vir onmental Ef f ects Photo g aller y PRIMARY EFFECTS January 3, 1911, Chon Kemin, Kirgyzstan earthquake (Ms=8.2). A fault slip of more than ten meters was produced by one single seismic event. In such a case, a paleoseismological trench needs to be very deep to recognize past events (centre of photo, man for scale). - Un rigetto di oltre 10 metri venne generato da un singolo evento sismico. In questi casi servono trincee paleosismiche molto estese per ricostruire gli eventi precedenti (per confronto, si osservi l’uomo al centro della foto). Photo: E. Vittori December 4, 1957, Mogod, Gobi-Altay earthquake (Mw=8.1). Bogd Toromhon coseismic fault rupture: 6 m of left lateral and 5 m (cfr. Shmulik Marco + Kelvin Berryman + Thomas Rockwell) of vertical slip. - Fagliazione superficiale cosismica a Bogd Toromhon: lo spostamento cosismico è stato pari a circa 6 metri di movimento laterale sinistro, e a circa 5 m (cfr. Shmulik Marco + Kelvin Berryman + Thomas Rockwell) di dislocazione verticale. Photo: R. Amit March 27, 1964 Alaska earthquake (Mw=9.2). Hanning Bay fault scarp on Montague Island. Vertical displacement in the foreground, in rock, is about 3.6 m. The maximum measured displacement of 4.2 m is at the beach ridge near the trees in the background. - Scarpata di faglia di Hanning Bay, Montague Island. In primo piano, la dislocazione verticale è pari a 3,6 m. La massima dislocazione, pari a 4,2 m, è stata misurata vicino agli alberi sullo sfondo. Source: U.S. Geological Survey Photographic Library (http://libraryphoto.cr.usgs.gov) . Published on U.S. Geological Survey Professional paper 541. 28 MICHETTI A.M. ET ALII December 7, 1988 Spitak, Armenia earthquake (Ms 6.9). Coseismic surface rupture produced by one single event. Here the rupture cuts across the ground without clear morphological evidence of past tectonic activity. - Rottura cosismica superficiale prodotta da un singolo terremoto. La rottura cosismica ha tagliato la superficie topografica in un punto in cui non si hanno evidenze morfologiche di attività tettonica precedente. Photo: E. Vittori December 7, 1988 earthquake, Spitak, Armenia, Ms=6.9. Evidence of coseismic surface faulting: local displacements are more than one meter. - Fagliazione superficiale cosismica: qui l’entità della dislocazione cosismica è superiore al metro. Source: CISTERNAS et alii, (1989). The Spitak (Armenia) earthquake of 7 December 1988: field observation, seismology and tectonics. Nature, 339, N 6227, p.675-679. September 27, 2003 Altai, Russia earthquake (Ms=7.4) Coseismic surface ruptures: local offsets of topographic surface are in the order of a few meters. - Rotture superficiali cosismiche: localmente le dislocazioni della superficie topografica sono dell’ordine di pochi metri. Photo: A. Ovsyuchenko 29 INTENSITY SCALE ESI 2007 October 28, 1983, Borah Peak, Nevada, USA, earthquake (Ms = 7.3) The height of fault scarp is locally in the order of one meter. A clear gentler sloping scarp indicates the penultimate event. - L’altezza della scarpata di faglia è pari a circa un metro. Un tratto della scarpata meno pendente indica il penultimo evento. Photo: E. Vittori December 16, 1954 Dixie Valley, Nevada, USA, earthquake (M = 7.2) Trace of the fault escarpment associated to this event. The mountain front is the result of repeated earthquakes like the 1954 event over a geological time interval. - Traccia della scarpata di faglia associata a questo evento. Il fronte montuoso è il risultato di ripetuti terremoti simili a quello del 1954 in un intervallo di tempo geologico. Photo: E. Vittori October 02, 1915 Pleasant Valley, Nevada, USA, earthquake (M = 7.8). Trace of the coseismic fault scarp and associated Mt. Tobin mountain front. - Traccia della scarpata di faglia e del fronte montuoso (Monte Tobin) ad essa associato. Photo: B. Slemmons 30 MICHETTI A.M. ET ALII January 17 1995, Kobe, Japan, earthquake (M=6.9). Hokudan, Awaji island: the surface rupture of the Nojima fault preserved inside a museum built on purpose. - Hokudan, isola di Awaji: la rottura superficiale della faglia di Nojima conservata all’interno di un museo appositamente costruito. Photo: L. Guerrieri January 13, 1915, Fucino, Central Italy, earthquake (M = 7.0). San Veneziano, Eastern border of the Fucino basin: Eye-witnesses have testified to Serva L. that coseismic displacement along the fault was about 80-90 cm. - San Veneziano, margine orientale del bacino del Fucino. Testimoni oculari hanno dichiarato a Serva L. che il rigetto cosismico lunga la faglia è stato pari ad 80-90 cm. Source: SERVA L., BLUMETTI A.M. & MICHETTI A.M. (1988) - Gli effetti sul terreno del terremoto del Fucino (13 gennaio 1915); tentativo di interpretazione dell’evoluzione tettonica recente di alcune strutture. Mem. Soc. Geol. It., 35, 893-907. INTENSITY SCALE ESI 2007 31 October 23, 2004, Chuetsu, Japan, earthquake (Mw=6.6). A trench exposure across the Obirou thrust fault which caused the earthquake. The scarp is the cumulative effect of several earthquakes. The last event produced offsets of only a few cm. - La parete di una trincea attraverso il thrust di Obirou che ha generato il terremoto. La scarpata è l’effetto cumulato di diversi terremoti. L’ultimo evento ha prodotto rigetti dell’ordine di pochi cm. Photo: T. Azuma 1811-1812 New Madrid (USA) earthquakes (Mw between 7.2 and 8.3). Reelfoot Lake, Tennessee, USA. This lake was formed by coseismic uplift triggered by a blind thrust that caused the inundation of the forested area in foreground. - Questo lago si è formato per il sollevamento cosismico innescato dalla riattivazione di un sovrascorrimento cieco che ha provocato l’inondazione dell’area forestata in primo piano. Photo: courtesy J. & D. Richardson Photography (http://www.jdrichardson.com/) SECONDARY EFFECTS February 5, 1783 Calabria earthquake (Mm=7.1). A seismically-induced landslide dammed the S. Cristina narrow valley and formed a temporary lake. - Una frana sismoindotta sbarrò la stretta valle di S. Cristina e formò un lago temporaneo. Source: Sarconi (1784) - Istoria de' fenomeni del Tremoto avvenuto nelle Calabrie e nel Valdemone nell’anno 1783. Reale Accademia delle Scienze, e delle Belle Lettere di Napoli. Naples. October 23, 2004 Chuetsu, Japan, earthquake (Mw=6.6). Seismically induced landslide in the hills of Yamakoshi. - Una frana sismoindotta sulle colline di Yamakoshi. Photo: T. Azuma 34 MICHETTI A.M. ET ALII January 25, 1999, Armenia, Colombia earthquake (M = 6.1). Seismically induced landslide at Cristales, Cajamarca. - Una frana sismoindotta a Cristales, Cajamarca. Photo: A.N. Gomez November 23, 1980 Irpinia-Basilicata, Italy earthquake (Ms = 6.9). S. Giorgio La Molara: coseismic reactivation of a landslide. - S. Giorgio La Molara: riattivazione cosismica di una frana. Source: Ufficio Tecnico Comune San Giorgio La Molara August 6, 2002 Bullas, Spain earthquake (VI MSK; 5.0 mb) A massive block of 25 m3 located 4 km from the epicentre rolled for several hundreds of meters. Another block of 15 m3 fell down in the same zone. Blocks were overturned during a second earthquake (VI MSK; 4.8 Mw), 2005 La Paca earthquake. - Un blocco di 25 m3 a circa 4 km dall’epicentro è rotolato per centinaia di metri. Un altro blocco di 15 m3 è caduto nella stessa zona. I blocchi sono stati rimobilizzati durante il terremoto del 2005 a La Paca (VI MSK; 4.8 Mw). Source: Murphy Corella, P. (2005) Field Report for the January 29th 2005 earthquakes in Lorca, Spain. http://www.proteccioncivilandalucia.org/Documentos/SismoLorca.htm INTENSITY SCALE ESI 2007 35 November 24, 2004, Salò, Italy earthquake (Ml=5.2). At Clibbio, along the Chiese River, large rockfalls with dolostone boulders up to ca. 75 m3 detached from the mountain slope of Mt. Acuto; two houses were hit by the boulders. - A Clibbio, lungo il fiume Chiese, imponenti frane di crollo con blocchi di dolomia di dimensioni anche fino a 75 m3 si sono staccati dal versante montuoso di Monte Acuto. Due case furono colpite dai blocchi. Photo: S. Porfido April 12, 1998 Bovec, Slovenia earthquake (Md = 5.6) - Two rock falls reactivated along the Mt. Cucla mountain slope. - Due frane di crollo si sono riattivate lungo il versante montuoso di Monte Cucla. Photo: P. Di Manna, E. Vittori 36 MICHETTI A.M. ET ALII July 12, 2004, Kobarid, Slovenia earthquake (Md = 5.1). Two small landslides along the Kobarid - Bovec road. - Due piccole frane lungo la strada Kobarid - Bovec. Photo: P. Di Manna, E. Vittori September 06, 2002, Palermo, Italy earthquake (ML=5.6). Cerda: trace of the main scarp of a ca. 500 m x 1500 m landslide. An ESI scale value of VII degree might be attributed based on such a landslide. However, the nearby village of Cerda and the country houses around the slide did suffer a MCS intensity V. No other similar or even smaller slides were observed in the area. This is a case where a specific analysis is required to verify if the isolated, though large, landslide, better portraits the local intensity or it should be disregarded. - Cerda: un tratto della corona di una frana di dimensioni pari a circa 500 m x 1500 m. Si potrebbe attribuire a questo effetto un grado di intensità ESI pari a VII. Tuttavia, al vicino paese di Cerda e alle case adiacenti alla frana è stata attribuita un intensità MCS pari a V. Non sono stati osservati altri movimenti di versante nell’area. Questo è un caso in cui è necessaria un analisi specifica con l’obiettivo di verificare se un fenomeno franoso isolato, anche se molto esteso, sia rappresentativo dell’intensità locale o se invece debba essere ignorato. Photo: E. Vittori INTENSITY SCALE ESI 2007 37 March 27, 1964 Alaska earthquake (Mw = 9.2). Collapse pits at Kasilof formed after eruptions of ground water and sand. The pit in the foreground is about one meter in diameter. - Kasilof, cavità di collasso formate dalle eruzioni di acqua sotterranea e sabbia. La cavità in primo piano ha un diametro di circa un metro. Photo by H.L. Foster, 1964. U.S. Geological Survey Professional paper 543-F. May 27, 1995 Neftegorsk earthquake (Ms=7.4). A ground collapse occurred after the earthquake. - Un collasso occorso a seguito del terremoto. Source: IVASHCHENKO et alii, (1995). Neftegorskoye zemletryaseniye 27(28) maya 1995 g. na Sakhaline. (The Neftegorsk 27(28) May, 1995, earthquake in Sakhalin - in Russian). // In: Federal’naya sistema seismologicheskikh nablyudeniy i prognoza zemletryaseniy. Neftegorskoye zemletryaseniye 27 (28).05.1995. Moskva, 48-67. March 3, 1872 Owens Valley, California, USA earthquake (Ms=7.6). Owens Lake: aligned mud volcanos in the playa of the lake, dried in 1925. - Owens Lake: vulcanelli di fango allineati sul fondo del lago, prosciugato nel 1925. Photo: E. Vittori 38 MICHETTI A.M. ET ALII November 22, 1995 Nuweiba, Sinai, earthquake, (MW=7.2). Gulf of Elat - Aqaba: an about one meter large sand blow with coarse sand on its surface, suggesting that coarser material was likely ejected during a late liquefaction phase. - Golfo di Elat - Aqaba: un vulcanello di sabbia di circa un metro con sabbia grossolana in superficie. Il materiale grossolano dovrebbe essere fuoriuscito in una fase tardiva del fenomeno di liquefazione. Source: The November 22, 1995 Nuweiba earthquake, Gulf of Elat - Aqaba: post-seismic analysis of failure features and seismic hazard implications. Edited by Hillel Wust, Report GSI/3/97, Elat. October 23, 2004 Chuetsu, Japan, earthquake (Mw=6.6). Kawabukuro: a sand bowl a few meters wide. - Kawabukuro: un vulcanello di sabbia ampio diversi metri. Photo: T. Azuma August 14, 2003, Lefkada, Ionian Sea, Greece, earthquake (Mw=6.2). Ground crater in the sandy beach of Agios Nikitos. - Un cratere formatosi nella spiaggia sabbiosa di Agios Nikitos. Source: Earth Planets Space, 55, 713718, 2003 (G.A. PAPADOPOULOS, V. KARASTATHIS, A. GANAS, S. PAVLIDES, A. FOKAEFS & K. ORFANOGIANNAKI). 39 INTENSITY SCALE ESI 2007 November 24, 2004, Salò, Italy, earthquake (Ml=5.2) Salò: in the harbor evidence of liquefaction and localized (over an area of ca. 500 m2) lateral spreading was observed, with fissuring up to 30 cm wide parallel to the waterfront area. - Salò: nel porto sono state osservate evidenze di liquefazione ed espandimenti laterali localizzati in un area di circa 500 m2, con fessure ampie fino a 30 cm parallele al fronte del porto. Photo: E. Esposito October 18, 1992, Murindo, Colombia earthquake (Mw=7.1) Murindo River basin, Colombia: The vegetation cover was heavily damaged and trees collapsed even in flat areas. - Bacino del fiume Murindo, Colombia: La copertura vegetale venne profondamente devastata e alberi caddero anche in aree pianeggianti. Photo: E. Parra October 18, 1992, Murindo, Colombia earthquake (Mw=7.1) Damaquiel Island (50m x 150m) emerged in the Gulf of Uraba Colombia. - L’isola di Damaquiel (50 m x 150 m) emerse nel Golfo di Uraba, Colombia. Photo: E. Parra 40 MICHETTI A.M. ET ALII October 18, 1992, Murindo, Colombia earthquake (Mw=7.1) San Pedro de Uraba: the Cacahual mudvolcano erupted some minutes after the event emitting gas that burnt for days. - San Pedro de Uraba: il mud-volcano di Cacahual ha iniziato ad eruttare alcuni minuti dopo l’evento con emissioni gassose che alimentarono incendi per diversi giorni. Photo: E. Parra March 27, 1964, Alaska earthquake (Mw=9.2). Shoup Bay: a boulder estimated to weigh almost 800 kg was thrown 27 m above the shoreline. - Shoup Bay: un enorme blocco il cui peso è stato stimato pari a quasi 800 kg è stato scagliato fino a 27 metri sopra la linea di costa. Photo by G. Plafker, 1964. Figure 4, U.S. Geological Survey Professional paper 542-G. 41 INTENSITY SCALE ESI 2007 February 11, 2004, Northeastern Dead Sea earthquake (ML=5.2). Anomalous wave in the Dead Sea, half an hour after the event. - Un onda anomala nel Mar Morto, mezz’ora dopo l’evento. Source: SALAMON, A., 2005. Natural seismogenic effects of the February 11, 2004, ML=5.2, Dead Sea earthquake, Israel Journal of Earth Sciences, 54, 145-169). Photo taken by C. Barghoorn February 11, 2004, Dead Northeastern Sea earthquake (ML=5.2). Ponds along the Darga coast, probably formed by the run-up wave of a small tsunami. - Pozze d’acqua lungo la costa di Darga, formate probabilmente dall’onda di run-up di un piccolo tsunami. Source: SALAMON, A., 2005. Natural seismogenic effects of the February 11, 2004, ML=5.2, Dead Sea earthquake, Israel Journal of Earth Sciences, 54, 145169). Photo taken by G. Baer. APPENDIX II ESI 2007 F or m ESI 2007 Form This 2 pages - form has to be used for field surveys immediately after the earthquake and for the revision of environmental effects from historical sources. It is designed at the site level (one different form for each different site). Fields in Italic should be filled when required information is available. A complete Guide to Compilation is available at the end of this Form. Authors & Institution 1. ____________________________________________________________________________________________________ 2. ____________________________________________________________________________________________________ 3._____________________________________________________________________________________________________ 4._____________________________________________________________________________________________________ 5._____________________________________________________________________________________________________ Earthquake Earthquake Code __________________ Earthquake Region _____________________________________________ Year________ Month ______ Day_______ Greenwich Time______________Epicentral Intensity_______ Intensity type______ Magnitude_______________ Magnitude type________________ Focal Depth (km) _______ Depth accuracy_______ Latitude __________________ Longitude__________________________Earthquake References_________________________ Surface faulting (yes/not): _________________ Map of rupture zone (available /not available) _________________________ Maximum Displacement (cm) ______Total Rupture Length (km)______ Slip-sense ____________________________________ Surface faulting References_______________________________________________________________________________ Area of max secondary effects (kms) _________ Reference for secondary effects _______________________________________ ESI epicentral intensity assessment _______________ Locality Locality Code______________________ EEE-Survey Date ______________ Surveyors _______________________________ Locality ______________________ Town/District______________ Locality length (m) _________ Locality width (m) ________ Latitude _________________ Longitude ____________________ Altitude (m) __________ Location accuracy ______________ Distance from epicentre (km) _________ Local PGA (g) ______ Geomorphological setting_______________________________ Local Macroseismic Intensity _____________ Intensity type______ EEE site EEE Code__________________ EEE type____________________ Site length (m) _________ Site width (m) _____________ Site position _____________________Latitude __________ Longitude ___________ Altitude (m) ______ Loc. accuracy _____ Description ________________________________________________________________________________________ Notes on the site ____________________________________________________________________________________ Bedrock lithology_______________________________________ Soft sediment lithology __________________________ Strength_____________________________________________ Structure______________________________________ EEE Site References __________________________________________________________________________________ Effects on man-made structures Type of man-made structures _____________________________________________________________________________ Level of damage _________________________ Single/multiple _________________________________________________ Surface faulting Strike (°) ______ Dip (°) _____ Slip vector (°) ______ Type of movement__________________________________________ Vertical Offset (cm) ___________ Horizontal Offset (cm) ______ Displaced features _________________________________ Length of fault segment (km) ________ Scarp ________ Associated features:________________________________________ Hydrologic anomalies Surface water effects____________________________________ Ground water effects________________________________ Temperature Anomaly Chemical anomaly Temperature change (°C) ________ Discharge anomaly Discharge change (l/s)_________ Change chemical components________________ Gas emission Gas element _____________ Duration of anomaly (days) __________ Time delay (hrs) __________ Velocity_______________________________________ Anomalous waves/tsunami Max wave height (m) _________ Width (m) ___________ Length of affected coast (km) ________ Time delay (min) _________ Description____________________________________________________________________________________________ Ground cracks Origin________________________________ Strike (°) ______ Dip (°) _____ Shape___________________________ Max opening (cm) _______________ Areal density (Nr/m2) _________________ Length (m) ___________________________ Slope movements Type_________________________________ Max dimension of blocks (m3) __________Total volume (m3)________________ Linear density (Nr/m) ____________ Areal density (Nr/m2) ____________________ Humidity__________________________ Time delay (hrs) _____________________ Width (m) _____________________ Slip amount (m) __________________ Liquefactions Type____________________________________ Max diameter (m) _____________ Linear density (Nr/m) ________________ Areal densit y (Nr/m2) ________ Max lowering/uplift (m) _________ Shape _________________________________________ Humidity_________________________ Depth of water table (m) ___________ Water ejection Sand ejection Velocity ____________________________________ Time delay/advance (hrs) _____________________________________ Other effects Three shaking Dust clouds Jumping stones Other__________________________________ Description_____________________________________________________________________________________________ Sketch ESI local intensity assessment _______________ ESI 2007 Form - Guide to Compilation Authors & Institution: List of the authors of this form (Surname, First Name, Institution, Country). Earthquake Earthquake Code: it is the primary key (univocal) for the table “Earthquake” It is composed by 11 digits: o 2 digits for country code for Regional Working Group (i.e. GR for Greece) that can be different from the country of epicentre; o 8 digits for date (yyyymmdd); o 1 digit according to the type of shock (m = main shock; a = aftershock; f = foreshock). Earthquake Region: “epicentral area, country” or “name of the earthquake” (i.e. San Francisco, California, US); Year, Month & Day: the date of the event. Please specify if it original date or converted date. Greenwhich Time: when available, please specify. Epicentral Intensity & Intensity type: MCS= Mercalli, Cancani, Sieberg; MM = Modified Mercalli intensity; EMS98 = European Macroseismic Scale; MSK64 = Medvedev, Sponhauer, Karnik; JMA = Japanese Meterological Agency-Intensity Scale. If you do not know the intensity type, please select “Not identified”. Magnitude & Magnitude type: select from the menu (Ml / Mb / M / Ms / Md/ Mw / MbLg / Mm). Focal Depth & Depth accuracy: in km. Latitude, Longitude & datum: two numerical fields for the coordinates of the epicentre. Datum must be WGS84. Earthquake References: the Agency providing source parameters and/or a list of data source for the earthquake. Surface faulting: YES or NOT, according to the SF reference cited below. If there is no information about surface faulting, please select “Unknown”. Map of rupture zone: click the option if it is available. Max D & SRL: maximum displacement (in cm) and Surface Rupture Length (in km) of the rupture zone. Slip-sense: choose the option (normal/reverse/oblique/right-lateral/left-lateral). Surface faulting References: the data source for surface faulting parameters (published paper and/or a personal observation). Area of maximum secondary effects: the size (in km2) of the area where maximum secondary effects occurred. SecEff References: references for the definition of the area of maximum secondary effects. ESI epicentral intensity: epicentral intensity assessment based on EEE effects at the total affected area level. Locality Locality Code: it is the primary key (univocal) for the table “Locality”, composed by the first 8 digits of the locality name (truncated). Es: SANFRANC. EEE-Survey Date: when the EEE effects of this locality have been described. Surveyors: the list of surveyors. Length & Width: the size of locality in meters. Locality and Town/District: the name of the locality and the closest town/district. Latitude, Longitude, Altitude & Location accuracy: the coordinates and the elevation (m) of the centroid of locality area. Accuracy in km. Distance from epicentre: in km. Local PGA: peak ground acceleration data (in g), when available. Geomorphological setting: select a geomorphological environment from the list (Mountain slope /Mountain valley/Hillslope/Alluvial fan/Bajada/Delta/Alluvial plain/Alluvial terrace/Marsh/Sea-river cliff/River-lake bank/Sea-lake shore/Aridsemiarid flat/Desert). Local Macroseismic Intensity: local intensity values according to classical traditional scales (do not confuse with ESI intensity!!). EEE site EEE Code: it is the primary key (univocal) for the table “EEE Effects”, composed by 11 digits (8 digits of locality code + 1 + 2 digits for counter). Es: SANFRANC101. If another earthquake recorded in this database has hit the same locality you should insert 2 (instead of 1) between the 8 digits for locality code and the 2 digits for counter ). Es. SANFRANC201. Site position: describe the position of the site within the locality (50 digits). Length & Width: the size of site in meters. Latitude, Longitude, Altitude & Location accuracy: the coordinates and the elevation (m) of the EEE site. Accuracy in m. Description: a description of the effect as reported by the original observer (essential for historical earthquakes). In this field you should include description of the evolution in time of the effect. Notes: any additional information on the site. Bedrock lithology: select from the menu (Intrusive/Volcaniclava/Pyroclastic/Metamorphic/Shale/Sandstone/Conglomerate/Limestone/Salt). Soft sediment lithology: select from the menu (Soil/Clay/Silt/Sand/Gravel). Strength: select from the menu (hard/semi-coherent/soft). Structure: select from the menu (massive/stratified/densely cleaved). EEE Site References: cite the document supporting the EEE description. EEE type: select the dominant type of EEE effect in this site: Surface faulting - Slope movements - Ground cracks - Ground settlements - Hydrological anomaly – Tsunami - Not geological effects. Effects on man-made structures Type of man-made structure: select from the menu (Buildings/Bridge/Viaduct/Railway/Tunnel/Paved road/Unimproved road/Highway). Level of damage: select from the menu (partially damaged/collapsed). Single/Multiple: choose the option. Surface faulting Strike, Dip & Slip vector: in degrees. Slip sense: . it can be different from the general trend of movement. Select from the list (normal/reverse/oblique/strike-slip dextral/ strike-slip sinistral). Vertical Offset & Horizontal Offset: in cm. Displaced features: type the displaced features (i.e. alluvial fan deposits, limestone, erosional terrace, etc.); Length of fault segment: in km. Scarp: select single/multiple. Associated features: select from the menu (Gravity graben/Push-up/Pull-a-part/Mole track). Hydrologic anomalies Surface water effects: select from the menu (Surface waters effects/Overflow/Waves/Water fountain/Discharge variation/ Turbidity of river/Seiches/Temporary sea-level change/Temporary lake-level change). Ground water effects: select from the menu (Drying up of springs/Appearance of springs/Temperature/Chemical component/ Turbidity of springs). Temperature Anomaly &Temperature change: in case, click the option and estimate the change in °C. Discharge anomaly & Discharge change: in case, click the option and estimate the change in l/s Chemical anomaly & Change chemical components: in case, click the option and record the anomalous chemical component. Gas emission & Gas element: in case, click the option and record the anomalous gas element. Duration of anomaly: in days. Time delay: in hours. Velocity: select from the menu (Extremely slow/Very slow/Slow/Moderately rapid/Rapid). Anomalous waves / Tsunami Max wave height: in meters. Width: the width of inundated land from the coast to the inner land, in meters. Length of affected coast: in km. Time delay: in minutes. Ground cracks Origin: select from the menu (slide/ground settling/detachment/ground shaking). Strike & Dip: in degrees. Areal density: Nr/m2. Shape: select from the menu (straight/Sinuous/Curvilinear/Max opening). Max opening: in cm. Length: in meters. Slope movements Type: select from the menu (Rock fall/Debris fall/Toppling/Rock slide/Debris slide/Avalanche/Mudslide/Debris flow/ Earth flow/Mud flow/Slow slide/Slow earth flow/Slow mud flow/Lateral spread/Sackung). Max dimension of blocks: in cubic meters. Total volume: in cubic meters. Linear density & Areal density: in Nr/m and in Nr/m2. Humidity: select from the menu (very wet/moderately wet/dry). Time delay: in hours. Width: the width of the sliding material (along the slope) in m. Slip amount: approximately, the amount of slip in m. Liquefactions Type: select from the menu (Liquefaction/Compaction/Subsidence/Bulge/Sinkhole/Ground failure) Max diameter: in meters Linear density & Areal density: Nr/m and Nr/m2 Max lowering/uplift: in meters Shape: select from the menu (Round/Elliptical/Elongated/Squared positive cone / Squared negative cone) Humidity: select from the menu (Very wet/Moderately wet/Dry) Depth of water table: in meters. Water ejection & Sand ejection: in case, click the option Velocity: select from the menu (Extremely slow/Very slow/Slow/Moderately rapid/Rapid) Time delay/advance: in hours Other effects Select the type of effect Description: add detailed characteristics of the effect ESI local intensity assessment The final assessment of local intensity on the basis of the ESI 2007 Plate I - Synoptic Table of ESI 2007 Intensity Degrees - The accuracy of the assessment improves in the higher degrees of the scale, in particular in the range of occurrence of pri- - Quadro sinottico dei Gradi di Intensità della scala ESI 2007 - L’accuratezza della valutazione aumenta verso i gradi più alti della scala, in particolare nell’intervallo di occorrenza degli effetti primari che mary effects, typically starting from intensity VIII, and with growing resolution for intensity IX, X, XI and XII. Hence, in the yellow group of intensity degrees (VIII- tipicamente iniziano a manifestarsi dall’VIII grado con risoluzione crescente fino al XII grado. Pertanto, per i gradi di intensità in giallo (VIII-X) gli effetti sull’ambiente naturale sono una componente essenziaX) the effects on natural environment are an essential component of seismic intensity that cannot be disregarded. In the orange group of intensity degrees (XI-XII) they become le dell’intensità che non può essere ignorata. Per i gradi di intensità in arancio (XI e XII), essi sono lo strumento più affidabile per la valutazione dell'intensità. the most effective tool for intensity assessment. PRIMARY EFFECTS Surface faulting and deformations S E C O N D A R Y E F F E C TS Hydrological anomalies There are no environmental effects From I to III IV VI VII VIII Marginal effects in the environment SLIGHTLY DAMAGING Modest effects in the environment Jumping stones TOTAL AREA Exceptionally, rocks may fall and small landslide may be (re)activated, along slopes where the equilibrium is already near the limit state, e.g. steep slopes and cuts, with loose and generally saturated soil. Absent Rare variations of the water level in wells and/or of the flow-rate of springs are locally recorded, as well as small variations of chemical-physical properties of water and turbidity in lakes, springs and wells. In closed basins (lakes, even seas) seiches with height of decimeters may develop, sometimes noted also by naked eye, typically in the far field of strong earthquakes. Anomalous waves up to several tens of cm high are perceived by all people on boats and on the coast. Water in swimming pools overflows. Thin cracks (millimeter-wide and several cms up to one meter long) are locally seen where lithology (e.g., loose alluvial deposits, saturated soils) and/or morphology (slopes or ridge crests) are most prone to this phenomenon. Rare small rockfalls, rotational landslides and slump earth flows may take place, along often but not necessa- Tree limbs and bushes rily steep slopes where equilibrium is near the limit state, shake slightly, very rare mainly loose deposits and saturated soil. Underwater cases of fallen dead landslides may be triggered, which can induce small ano- limbs and ripe fruit. malous waves in coastal areas of sea and lakes. Absent Significant variations of the water level in wells and/or of the flow-rate of springs are Anomalous waves up to many tens of cm high flood locally recorded, as well as small variations of very limited areas nearshore. Water in swimming chemical-physical properties of water and pools and small ponds and basins overflows. turbidity in lakes, springs and wells. Occasionally, millimeter-centimeter wide and up to several meters long fractures are observed in loose alluvial deposits and/or saturated soils; along steep slopes or riverbanks they can be 1-2 cm wide. A few minor cracks develop in paved (either asphalt or stone) roads. Rockfalls and landslides with volume reaching ca. 103 m3 can take place, especially where equilibrium is near the limit state, e.g. steep slopes and cuts, with loose saturated soil, or highly weathered / fractured rocks. Underwater landslides can be triggered, occasionally provoking small anomalous waves in coastal areas of sea and lakes, commonly seen by intrumental records. Tree limbs shake feebly. Absent Absent Absent ------ Extremely rare cases are reported of liquefaction (sand boil), small in size and in areas most prone to this phenomenon (highly susceptible, recent, alluvial and coastal deposits, nearsurface water table). Absent Absent ------ Absent Absent ------ Absent Absent The total affected area is in the order of 10 km 2. In dry areas, dust clouds may rise from the ground in the epicentral area. Stone sand even small boulders and tree trunks may be thrown in the air, leaving typical imprints in soft soil. The total affected area is in the order of 100 km2. Trees and bushes shake moderately to strongly; a very few tree tops and unstable-dead limbs may break and fall, also depending on species, fruit load and state of health. Rare cases are reported of liquefaction (sand boil), small in size and in areas most prone to this phenomenon (highly susceptible, recent, alluvial and coastal deposits, near surface water table). Scattered landslides occur in prone areas, where equilibrium is unstable (steep slopes of loose / saturated soils), while modest rock falls are common on steep gorges, cliffs). Their size is sometimes significant (103 - Trees and bushes 105 m3); in dry sand, sand-clay, and clay soil, the volu- shake vigorously; mes are usually up to 100 m3. Ruptures, slides and falls especially in densely may affect riverbanks and artificial embankments and forested areas, many excavations (e.g., road cuts, quarries) in loose sediment limbs and tops or weathered / fractured rock. Significant underwater break and fall. landslides can be triggered, provoking anomalous waves in coastal areas of sea and lakes, directly felt by people on boats and ports. Rare cases are reported of liquefaction, with sand boils up to 50 cm in diameter, in areas most prone to this phenomenon (highly susceptible, recent, alluvial and coastal deposits, near surface water table). Fractures up to 5-10 cm wide and up to hundred metres long are Anomalous waves even higher than a meter may observed, commonly in loose alluflood limited nearshore areas and damage or wash vial deposits and/or saturated away objects of variable size. Water overflows from soils; rarely, in dry sand, sandclay, and clay soil fractures are small basins and watercourses. also seen, up to 1 cm wide. Centimeter-wide cracks are common in paved (asphalt or stone) roads. Observed rarely. Ground ruptures (surface faulting) may develop, up to several hundred meters long, with offsets not exceeding a few cm, particularly for very shallow focus earthquakes such as those common in volcanic areas. Tectonic subsidence or uplift of the ground surface with maximum values on the order of a few centimeters may occur. Springs may change, generally temporarily, their flow-rate and/or elevation of outcrop. Some small springs may even run dry. Variations in water level are observed in wells. Weak variations of chemical-physical properties of water, most commonly temperature, may be observed in springs and/or wells. Water turbidity may appear in closed basins, rivers, wells and springs. Gas emissions, often sulphureous, are locally observed. Anomalous waves up to 1-2 meters high flood nearshore areas and may damage or wash away objects of variable size. Erosion and dumping of waste is observed along the beaches, where some bushes and even small weak-rooted trees can be eradicated and drifted away. Water violently overflows from small basins and watercourses. Fractures up to 50 cm wide and up to hundreds metres long, are commonly observed in loose alluvial deposits and/or saturated soils; in rare cases fractures up to 1 cm can be observed in competent dry rocks. Decimetric cracks are common in paved (asphalt or stone) roads, as well as small pressure undulations. Small to moderate (103 - 105 m3) landslides are widespread in prone areas; rarely they can occur also on gentle slopes; where equilibrium is unstable (steep slopes of loose / saturated soils; rock falls on steep gorges, coastal cliffs) Trees shake vigorously; their size is sometimes large (105 - 106 m3). Landslides branches may break can occasionally dam narrow valleys causing temporary and fall, trees may be or even permanent lakes. Ruptures, slides and falls affect uprooted, especially riverbanks and artificial embankments and excavations along steep slopes. (e.g., road cuts, quarries) in loose sediment or weathered / fractured rock. Frequent is the occurrence of landslides under the sea level in coastal areas. Liquefaction may be frequent in the epicentral area, depending on local conditions; the most typical effects are: sand boils up to ca. 1 m in diameter; apparent water fountains in still waters; localised lateral spreading and settlements (subsidence up to ca. 30 cm), with fissuring parallel to waterfront areas (river banks, lakes, canals, seashores). Observed commonly. Effects in the Ground ruptures (surface faulting) develop, up environment are a to a few km long, with offsets generally in the widspread source of order of several cm. Tectonic subsidence or uplift considerable hazard and of the ground surface with maximum values in become important for the order of a few decimeters may occur. Springs can change, generally temporarily, their flow-rate and/or location to a considerable extent. Some modest springs may even run dry. Temporary variations of water level are commonly observed in wells. Variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Water turbidity is common in closed basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. Meters high waves develop in still and running waters. In flood plains water streams may even change their course, also because of land subsidence. Small basins may appear or be emptied. Depending on shape of sea bottom and coastline, dangerous tsunamis may reach the shores with runups of up to several meters flooding wide areas. Widespread erosion and dumping of waste is observed along the beaches, where bushes and trees can be eradicated and drifted away. Fractures up to 100 cm wide and up to hundreds metres long are commonly observed in loose alluvial deposits and/or saturated soils; in competent rocks they can reach up to 10 cm. Significant cracks are common in paved (asphalt or stone) roads, as well as small pressure undulations. Landsliding is widespread in prone areas, also on gentle slopes; where equilibrium is unstable (steep slopes of loose / saturated soils; rock falls on steep gorges, coastal cliffs) their size is frequently large (105 m3), sometimes very large (106 m3). Landslides can dam narrow valleys causing temporary or even permanent lakes. Riverbanks, artificial embankments and excavations (e.g., road cuts, quarries) frequently collapse. Frequent are large landslides under the sea level in coastal areas. Liquefaction and water upsurge are frequent; sand boils up to 3 m in dia- In dry areas, meter; the most typical effects dust clouds are:apparent water fountains in still may waters; frequent lateral spreading and rise from settlements (subsidence of more than the ground. ca. 30 cm), with fissuring parallel to waterfront areas (river banks, lakes, canals, seashores). Many springs significantly change their flow-rate and/or elevation of outcrop. Some springs may run temporarily or even permanently dry. Temporary variations of water level are commonly observed in wells. Even strong variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Often water becomes very muddy in even large basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. Meters high waves develop in even big lakes and rivers, which overflow from their beds. In flood plains rivers may change their course, temporary or even permanently, also because of widespread land subsidence. Basins may appear or be emptied. Depending on shape of sea bottom and coastline, tsunamis may reach the shores with runups exceeding 5 m flooding flat areas for thousands of meters inland. Small boulders can be dragged for many meters. Widespread deep erosion is observed along the shores, with noteworthy changes of the coastline profile. Trees nearshore are eradicated and drifted away. Open ground cracks up to more than 1 m wide and up to hundred metres long are frequent, mainly in loose alluvial deposits and/or saturated soils; in competent rocks opening reaches several decimeters. Wide cracks develop in paved (asphalt or stone) roads, as well as pressure undulations. Large landslides and rock-falls (> 105 - 106 m3) are fre- Trees shake vigorously; quent, practically regardless of equilibrium state of the slo- many branches and tree pes, causing temporary or permanent barrier lakes. River trunks break and fall. banks, artificial embankments, and sides of excavations typi- Some trees might be cally collapse. Levees and earth dams may also incur serious damage. Frequent are large landslides under the sea level in uprooted and fall. coastal areas. Liquefaction, with water upsurge and soil compaction, may change the aspect of wide zones; sand volcanoes may even be more than 6 m in diameter; vertical subsidence even > 1m; large and long fissures due to lateral spreading are common. Boulders (diameter in excess of 2-3meters) In dry areas, can be thrown in the The total dust clouds air and move away affected area is in the from their site for commonly order of rise from the hundreds of meters ground. down even gentle slopes, 5,000 leaving typical km2. imprints in soil. Are dominant. Surface faulting extends from several tens of km up to more than one hundred km, accompanied by slips reaching several meters. Gravity graben, elongated depressions and pressure ridges develop. Drainage lines can be seriously offset. Tectonic subsidence or uplift of the ground surface with maximum values in the order of numerous meters may occur. Many springs significantly change their flow-rate and/or elevation of outcrop. Many springs may run temporarily or even permanently dry. Temporary or permanent variations of water level are generally observed in wells. Even strong variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Often water becomes very muddy in even large basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. Large waves develop in big lakes and rivers, which overflow from their beds. In flood plains rivers can change their course, temporary or even permanently, also because of widespread land subsidence and landsliding. Basins may appear or be emptied. Depending on shape of sea bottom and coastline, tsunamis may reach the shores with runups reaching 15 meters and more devastating flat areas for kilometers inland. Even meter-sized boulders can be dragged for long distances. Widespread deep erosion is observed along the shores, with noteworthy changes of the coastal morphology. Trees nearshore are eradicated and drifted away. along the shores, with noteworthy changes of the coastline profile. Trees nearshore are eradicated and drifted away. Open ground cracks up to several meters wide are very frequent, mainly in loose alluvial deposits and/or saturated soils. In competent rocks they can reach 1 m. Very wide cracks develop in paved (asphalt or stone) roads, as well as large pressure undulations. Large landslides and rock-falls (> 105 - 106 m3) are frequent, practically regardless of equilibrium state of slopes, causing many temporary or permanent Trees shake vigorously; barrier lakes. River banks, artificial embankments, many branches and tree and sides of excavations typically collapse. Levees trunks break and fall. Many trees are and earth dams incur serious damage. Significant landslides can occur even at 200 – 300 km distance uprooted and fall. from the epicenter. Frequent are large landslides under the sea level in coastal areas. Liquefaction changes the aspect of extensive zones of lowland, determining vertical subsidence possibly exceeding several meters; numerous large sand volcanoes, and severe lateral spreading can be observed. In dry areas dust clouds arise from the ground. Big boulders (diameter of several meters) can be thrown in the The total air and move away affected area from their site for is in the long distances down order of even gentle slopes, 10,000 leaving typical km2. imprints in soil. Are dominant. Surface faulting is at least few hundreds of km long, accompanied by offsets reaching several tens of meters. Gravity graben, elongated depressions and pressure ridges develop. Drainage lines can be seriously offset. Landscape and geomorphological changes induced by primary effects can attain extraordinary extent and size (typical examples are the uplift or subsidence of coastlines by several meters, appearance or disappearance from sight of significant landscape elements, rivers changing course, origination of waterfalls, formation or disappearance of lakes). Many springs significantly change their flowrate and/or elevation of outcrop. Temporary or permanent variations of water level are generally observed in wells. Many springs and wells may run temporarily or even permanently dry. Strong variations of chemical-physical properties of water, most commonly temperature, are observed in springs and/or wells. Water becomes very muddy in even large basins, rivers, wells and springs. Gas emissions, often sulphureous, are observed, and bushes and grass near emission zones may burn. Giant waves develop in lakes and rivers, which overflow from their beds. In flood plains rivers change their course and even their flow direction, temporary or even permanently, also because of widespread land subsidence and landsliding. Large basins may appear or be emptied. Depending on shape of sea bottom and coastline, tsunamis may reach the shores with runups of several tens of meters devastating flat areas for many kilometers inland. Big boulders can be dragged for long distances. Widespread deep erosion is observed along the shores, with outstanding changes of the coastal morphology. Many trees are eradicated and drifted away. All boats are tore from their moorings and swept away or carried onshore even for long distances. All people outdoor are swept away. Ground open cracks are very frequent, up to one meter or more wide in the bedrock, up to more than 10 m wide in loose alluvial deposits and/or saturated soils. These may extend up to several kilometers in length. Large landslides and rock-falls (> 1055 - 1066 m3) are frequent, practically regardless to equilibrium state of the slopes, causing many temporary or permanent barrier lakes. River banks, artificial embankments, and sides of excavations typically collapse. Levees and earth dams incur serious damage. Significant landslides can occur at more than 200 – 300 km distance from the epicenter. Frequent are very large landslides under the sea level in coastal areas. In dry areas dust clouds arise from the ground. Also very big boul- The total ders can be thrown in affected area the air and move for is in the long distances even order of down very gentle slo- 50,000 pes, leaving typical km 2 imprints in soil. and more Observed very rarely, and almost exclusively in volcanic areas. Limited surface DAMAGING fault ruptures, tens to hundreds of Appreciable effects in meters long and with centimetric offset, may occur, essentially associated to very the environment shallow earthquakes. HEAVILY DAMAGING Extensive effects in the environment Effects in the environment become a leading source of hazards and are critical for intensity assessment DEVASTATING Effects in the environment become decisive for intensity assessment, due to saturation of structural damage COMPLETELY DEVASTATING XII Dust clouds Significant temporary variations of the water level in wells and/or of the flow-rate of springs are locally recorded. Seldom, small springs may temporarily run dry or appear. Weak variations of chemical-physical properties of water and turbidity in lakes, springs and wells are locally observed. VERY DESTRUCTIVE XI Liquefactions that can be used as diagnostic Absent intensity assessment X Tree shaking Hair-thin cracks (millimeterwide) might be occasionally seen where lithology (e.g., loose alluvial deposits, saturated soils) and/or morphology (slopes or ridge crests) are most prone to this phenomenon. DESTRUCTIVE IX Slope movements In closed basins (lakes, even seas) seiches with height not exceeding a few centimeters may develop, commonly observed only by tidal gauges, exceptionally even by naked eye, typically in the far field of strong earthquakes. Anomalous waves are perceived by all people on small boats, few people on larger boats, most people on the coast. Water in swimming pools swings and may sometimes overflows. STRONG V Ground cracks Rare small variations of the water level in wells and/or of the flow-rate of springs are locally recorded, as well as extremely rare small variations of chemical-physical properties of water and turbidity in springs and wells, especially within large karstic spring systems, which appear to be most prone to this phenomenon. LARGELY OBSERVED First unequivocal effects in the environment Anomalous waves/tsunamis Effects in the environment are the only tool for intensity assessment Become leading. Surface faulting can extend for few tens of km, with offsets from tens of cm up to a few meters. Gravity grabens and elongated depressions develop; for very shallow focus earthquakes in volcanic areas rupture lengths might be much lower. Tectonic subsidence or uplift of the ground surface with maximum values in the order of few meters may occur. Trees shake vigorously; branches and thin tree trunks frequently break and fall. Some trees might be uprooted and fall, especially along steep slopes. Trees shake vigorously; many branches and tree trunks break and fall. Many trees are uprooted and fall. Liquefaction occurs over large areas and changes the morphology of extensive flat zones, determining vertical subsidence exceeding several meters, widespread large sand volcanoes, and extensive severe lateral spreading can be observed. Small boulders and tree trunks may be The total thrown in the air an- affected area d move away from is in the their site for meters, also depending on slope order of 1,000 angle and roundness, km 2. leaving typical imprints in soft soil.