Archaeological excavations at Troy, Mycenae, Pylos, and many other sites have brought to light re... more Archaeological excavations at Troy, Mycenae, Pylos, and many other sites have brought to light remains of the Mycenean period (13th to 11th c. BC) described by Homer in the Iliad and the Odyssey, but Homeric Ithaca and the nearby islands in the Ionian Sea remain an open question for more than 200 years. Analysis of Homeric verses has led to several scenarios for Ithaca (identified with modern Ithaki, Cephalonia, Leucas islands), and to nearly 10 scenarios for Asteris, the only well-described Homeric islet near Ithaca. Most of the scenarios for Asteris are not consistent with Odyssey which is supposed to offer accurate nautical information, while some authors suggest that this islet was modified, or even lost under the water during an earthquake. This article searches for Asteris independently from Ithaca, following a new methodology: Geological information, satellite imagery, aerial photos, modern maps, sailing data and field evidence are used to investigate (i) whether proposed scenarios for Asteris are consistent with its Homeric description, even after a geomorphological change; and (ii) whether any other islet in the Ionian Sea can justify the name Asteris, literary “star island”. It was found that Formicula, an ignored islet with a lighthouse can be regarded as a promising candidate for Homeric Asteris: Formicula is made of evaporite conglomerates and hence differs from all other limestone islets in the Ionian Sea, has all the characteristics of the Homeric islet: is located in the middle of the sea, has anchoring sites on two sides and a unique star-type pattern, the potential for an ambush site and also of a by-pass route; hence it can be regarded as a promising candidate for Homeric Asteris. This new finding may represent a benchmark for the search of the Homeric Ithaca.
The crest settlements of embankment dams with a central clay core are usually described as an exp... more The crest settlements of embankment dams with a central clay core are usually described as an exponential function of time. They play a major role in the safety and operational capacity of the dam, especially when taking into account that extreme crest settlements that have been observed for some of these dams have resulted in a significant reduction of the storage capacity of the reservoir and maintenance works at large scales and cost (e.g. Ataturk dam, Turkey). We studied the crest settlements of > 40 embankment dams, 10-41 years old, located at different parts of the world. Our analysis shows that the safety threshold for the crest settlements should not be a constant but increase with the age of the dam and that most of suggested thresholds in the literature are too conservative. A safety threshold of 1% (crest settlement to dam height ratio) appears to be realistic for the whole operational life of the dam. The Kremasta dam, whose age and size places it to a most critical s...
The 20 July 2017 Kos-Bodrum <em>M<sub>w</sub></em> 6.6 normal fault earth... more The 20 July 2017 Kos-Bodrum <em>M<sub>w</sub></em> 6.6 normal fault earthquake (AFAD, 2017) at the NW edge of the Quaternary Gökova Bay graben, was a destructive earthquake associated with a small tsunami (Yalciner et al., 2017). In addition, it is the first normal faulting earthquake in the Aegean covered by a dense array of continuous GPS stations which permit a detailed finite fault modeling (FFM). The preliminary seismological evidence (epicenters, hypocenters of the main shock and of the main aftershocks, and focal mechanism of the main shock) deriving from various agencies, data and techniques, indicate a shallow, nearly E-W striking normal faulting, but its details, including its dip (northerly or southerly) are not resolved. On the basis of independent analysis of seismological and geodetic data we obtained Finite Fault Models (FFM), which are very similar and hence describe the "true" fault.
We used a robotic total station (RTS), or robotic theodolite, or Total Positioning System (TPS) w... more We used a robotic total station (RTS), or robotic theodolite, or Total Positioning System (TPS) with a frequency of 2Hz to measure the instantaneous deflections at the top of one of the three 30m-high historical brick chimneys in the Gazi area (historical center of Athens) because of wind excitation. Measurements were made on reflectors already established on the top and the middle of these chimneys in the framework of a project to monitor their subsidence and tilting during the excavation of a line of the Athens Metro. Geodetic measurements were made under favorable meteorological conditions during four intervals, half to one hour long, during which the wind force 56 in the Beaufort scale velocity was fluctuating from a nearly stable direction, as indicated by recordings of a nearby meteorological station. The output of this study is that during this rather common wind event deflections of the top of the chimney along and across the direction of the wind were above the noise level ...
A cluster of earthquakes (6<Ms <7) characterized by strike slip faulting have occurred alon... more A cluster of earthquakes (6<Ms <7) characterized by strike slip faulting have occurred along the NW edge of the Aegean Arc in the Ionian Sea, the most seismically active region in Greece, in the last 30 years. The most recent earthquake was the 2015 (Mw 6.5) Leucas (Lefkada) earthquake. The modelling of these earthquakes, some of which are double events (2003 Leucas; 2014 Cephalonia) is a challenge for two main reasons. First, the geography of the area limits the distribution of the available seismological and GNSS stations and the correlations of INSAR data. Second, the structural pattern of the area indicates distributed thrusting but recent earthquakes are confined to the west margin of the Aegean Arc, usually assigned to the Cephalonia Transform Fault (CTF), and are dominated by strike slip faulting.
The epicentral area of the 2017, Mw 6.5 destructive Kos-Bodrum normal faulting earthquake, associ... more The epicentral area of the 2017, Mw 6.5 destructive Kos-Bodrum normal faulting earthquake, associated with a small tsunami in a touristic region, is located within the active Gokova graben and represents a case of a previously unrecognized, shallow normal fault without clear geomorphological signature. Analysis of teleseismic body-waveform data and geodetic data, both in the near- and far- field, indicate a well-constrained 25km long and 10km deep south-dipping normal fault which produced small uplift in the Bodrum peninsula. Modeled fault marks the NW edge of the actively extending part of the Gokova graben and was associated with two clusters of aftershocks, while only its eastern part correlates with known active faults. The 2017 earthquake seems to reflect an immature normal fault between Kos Island and the Anatolia mainland, and expansion of the Gokova graben, perhaps through echelon fractures, as is observed in seismic profiles farther east. Activation of normal faults with mo...
Various geophysical problems are described by redundant systems of highly non-linear systems of e... more Various geophysical problems are described by redundant systems of highly non-linear systems of equations with ≥3 unknown variables. Such systems are not possible to be solved with formal algebraic techniques, and are usually solved using sampling methods (mostly Monte Carlo-based), gradual optimization of certain of the unknown variables, a priori fixing of the values of some variables or in the vicinity of approximate solutions. In many cases, especially in the modeling of activated faults or of magma sources from surface displacements, such methods lead to sub-optimal solutions (trapped in local extrema, high uncertainties (trade-off) between certain variables, etc.) and highly influence the understanding/ modeling of certain complex geophysical processes.
Ground settlement above urban tunnels is a threat for nearby buildings, because it may lead to th... more Ground settlement above urban tunnels is a threat for nearby buildings, because it may lead to their differential settlement, tilting, and damage, depending on their structural characteristics, on ground conditions, and on the excavation procedure. Still, for few cases only details on ground settlement are known. In this article we analyze ground subsidence data during the excavation of Lines 2 and 3 of the Athens Metro. Based on this evidence, and in comparison with previous studies, we show that observations of elevation changes and of tilting of buildings may underestimate the amount of ground loss; this is because part of the ground deformation may be compensated by the stiffness of buildings or accommodated by internal deformation of sizeable buildings hosting measuring benchmarks. This effect can be described as static soil–structure interaction (sSSI), in analogy to the dynamic SSI produced during earthquakes. sSSI can produce bias in monitoring data above an advancing tunnel...
SUMMARY Exhaustive searches in regular grids is a traditional and effective method for inversion,... more SUMMARY Exhaustive searches in regular grids is a traditional and effective method for inversion, i.e. numerical solution of systems of non-linear equations which cannot be solved using formal algebraic techniques. However, this technique is effective for very few (3-4) variables and is slow. Recently, the first limitation was to a major degree overpassed with the new TOPological INVersion (TOPINV) algorithm which was used for inversion of systems with up to 18, or even more unknown variables. The novelty of this algorithm is that it is not based on the principle of the mean minimum misfit (cost function) between observations and model predictions, used by most inversion techniques. The new algorithm investigates for each grid-point whether misfits of each observation are within specified uncertainty intervals, and stores clusters of “successful” grid-points in matrix form. These clusters (ensembles, sets) of grid-points are tested whether they satisfy certain criteria and are then ...
Bulletin of the Geological Society of Greece, 2017
The tunnel of Eupalinos at Samos (Greece) is certainly one of the most admirable works in antiqui... more The tunnel of Eupalinos at Samos (Greece) is certainly one of the most admirable works in antiquity, but several questions concerning its plan, and especially the selection of its path, leading to an ‘S’ type curve, a longer tunnel and a longer aqueduct remain without an answer. In this paper we try to provide an answer to the question ‘why Eypalinos selected the specific path for the aqueduct?’ on the basis of geotechnical and geodetic evidence. Two basic criteria should have been satisfied for the tunnel planning: first, that it had to be excavated through rocks with mechanical properties suitable for a safe underground excavation, and second, that the portals should have been in areas permitting accurate geodetic orientation and guidance of the excavation. The overall selection of the tunnel path indicates that Eupalinos had an excellent understanding of the theory of errors and an ability for geological and geotechnical evaluation of the mechanical characteristics of the ground,...
Bulletin of the Geological Society of Greece, 2017
A strong earthquake (Mw 6.9) on 24 May 2014 ruptured the North Aegean Trough (NAT) in Greece, wes... more A strong earthquake (Mw 6.9) on 24 May 2014 ruptured the North Aegean Trough (NAT) in Greece, west of the North Anatolian Fault Zone (NAFZ). In order to provide unbiased constrains of the rupture process and fault geometry of the earthquake, seismological and geodetic data were analyzed independently. First, based on teleseismic long-period P- and SH- waveforms a point-source solution yielded dominantly right-lateral strike-slip faulting mechanism. Furthermore, finite fault inversion of broad-band data revealed the slip history of the earthquake. Second, GPS slip vectors derived from 11 permanent GPS stations uniformly distributed around the meizoseismal area of the earthquake indicated significant horizontal coseismic slip. Inversion of GPS-derived displacements on the basis of Okada model and using the new TOPological INVersion (TOPINV) algorithm permitted to model a vertical strike slip fault, consistent with that derived from seismological data. Obtained results are consistent w...
Abstract A submerged 2300 years-old mole or breakwater with a sigmoidal shape has been identified... more Abstract A submerged 2300 years-old mole or breakwater with a sigmoidal shape has been identified at the Palairos harbor (Akarnania, SW Greece mainland). Different possible scenarios could be proposed to explain this enigmatic shape for an ancient breakwater, such as selective erosion of the original structure, construction above existing shoals or reefs, gravity sliding and post-construction offset due to strike-slip faulting, but all these scenarios seem rather weak. Inspired by a large scale lateral offset of a retaining wall of a quay at the Barcelona harbor due to static liquefaction, by evidence of strike-slip earthquakes and of liquefaction potential in the study area, as well as by recent evidence for long-duration steady, nearly uni-directional dynamic displacements in the near-field of strike-slip faults, we propose an alternative scenario for this mole. An earthquake associated with strike-slip faulting and high acceleration produced liquefaction of the mole foundations and long duration, nearly unidirectional tectonic slip, while the later part of the steady slip produced additional secondary (surficial) slip on liquefied layers.
The plain of Thessaloniki is an important area from a historical standpoint. Numerous reigns and ... more The plain of Thessaloniki is an important area from a historical standpoint. Numerous reigns and empires have occupied the area, leaving behind numerous archaeological remains. The literature and historical evidences show that the city of Pella was located near the sea ...
Understanding the length and subdivisions of ancient length units is necessary for Archaeology, A... more Understanding the length and subdivisions of ancient length units is necessary for Archaeology, Architecture, and engineering, among other fields. These metrological units derive from anthropocentric concepts (fathom, cubit, foot, finger, etc.) and hence their metrological characteristics are variable and unknown for various ancient civilizations. The Roman length units are well determined, but the ancient Greek units are not. A rule sculpted in a metrological relief recently permitted the recognition of the Doric foot as having a length of 327 mm, but the broader use and divisions of this length unit remain unknown. In this article we present evidence of use of the Doric foot from the modeling of an ancient, atypical small theatre of the 4th-3rd century B.C., at Makyneia, on the western Greece mainland. It was found that this structure was designed using the Doric foot and its division in 24 (or even 12) digits. This result from a small provincial town indicates that the Doric foot was in broad use in architectural and engineering works of the ancient Greek World, and this result may be used to solve various problems of that era.
An intermediate depth earthquake sequence with an unusually strong aftershock hit Crete in 1810 a... more An intermediate depth earthquake sequence with an unusually strong aftershock hit Crete in 1810 and was felt in a very broad area. This seismic sequence was believed to have caused a death toll of about 2000-3000 and destroyed a major part of houses in the wider Heraklion area. In this article we present an unpublished note for this earthquake sequence from the memoirs of Frangiskos Limbritis, military and political personality in Crete, and analyze certain other notes from Crete and conclude that the death toll in Heraklion which was mainly affected was of the order of 300 and that structural damage was smaller than what believed in the past and was mostly rapidly repaired, especially in the meizoseismal area which roughly covers the present-day Heraklion prefecture (max intensities VIII-IX).
Archaeological excavations at Troy, Mycenae, Pylos, and many other sites have brought to light re... more Archaeological excavations at Troy, Mycenae, Pylos, and many other sites have brought to light remains of the Mycenean period (13th to 11th c. BC) described by Homer in the Iliad and the Odyssey, but Homeric Ithaca and the nearby islands in the Ionian Sea remain an open question for more than 200 years. Analysis of Homeric verses has led to several scenarios for Ithaca (identified with modern Ithaki, Cephalonia, Leucas islands), and to nearly 10 scenarios for Asteris, the only well-described Homeric islet near Ithaca. Most of the scenarios for Asteris are not consistent with Odyssey which is supposed to offer accurate nautical information, while some authors suggest that this islet was modified, or even lost under the water during an earthquake. This article searches for Asteris independently from Ithaca, following a new methodology: Geological information, satellite imagery, aerial photos, modern maps, sailing data and field evidence are used to investigate (i) whether proposed scenarios for Asteris are consistent with its Homeric description, even after a geomorphological change; and (ii) whether any other islet in the Ionian Sea can justify the name Asteris, literary “star island”. It was found that Formicula, an ignored islet with a lighthouse can be regarded as a promising candidate for Homeric Asteris: Formicula is made of evaporite conglomerates and hence differs from all other limestone islets in the Ionian Sea, has all the characteristics of the Homeric islet: is located in the middle of the sea, has anchoring sites on two sides and a unique star-type pattern, the potential for an ambush site and also of a by-pass route; hence it can be regarded as a promising candidate for Homeric Asteris. This new finding may represent a benchmark for the search of the Homeric Ithaca.
The crest settlements of embankment dams with a central clay core are usually described as an exp... more The crest settlements of embankment dams with a central clay core are usually described as an exponential function of time. They play a major role in the safety and operational capacity of the dam, especially when taking into account that extreme crest settlements that have been observed for some of these dams have resulted in a significant reduction of the storage capacity of the reservoir and maintenance works at large scales and cost (e.g. Ataturk dam, Turkey). We studied the crest settlements of > 40 embankment dams, 10-41 years old, located at different parts of the world. Our analysis shows that the safety threshold for the crest settlements should not be a constant but increase with the age of the dam and that most of suggested thresholds in the literature are too conservative. A safety threshold of 1% (crest settlement to dam height ratio) appears to be realistic for the whole operational life of the dam. The Kremasta dam, whose age and size places it to a most critical s...
The 20 July 2017 Kos-Bodrum <em>M<sub>w</sub></em> 6.6 normal fault earth... more The 20 July 2017 Kos-Bodrum <em>M<sub>w</sub></em> 6.6 normal fault earthquake (AFAD, 2017) at the NW edge of the Quaternary Gökova Bay graben, was a destructive earthquake associated with a small tsunami (Yalciner et al., 2017). In addition, it is the first normal faulting earthquake in the Aegean covered by a dense array of continuous GPS stations which permit a detailed finite fault modeling (FFM). The preliminary seismological evidence (epicenters, hypocenters of the main shock and of the main aftershocks, and focal mechanism of the main shock) deriving from various agencies, data and techniques, indicate a shallow, nearly E-W striking normal faulting, but its details, including its dip (northerly or southerly) are not resolved. On the basis of independent analysis of seismological and geodetic data we obtained Finite Fault Models (FFM), which are very similar and hence describe the "true" fault.
We used a robotic total station (RTS), or robotic theodolite, or Total Positioning System (TPS) w... more We used a robotic total station (RTS), or robotic theodolite, or Total Positioning System (TPS) with a frequency of 2Hz to measure the instantaneous deflections at the top of one of the three 30m-high historical brick chimneys in the Gazi area (historical center of Athens) because of wind excitation. Measurements were made on reflectors already established on the top and the middle of these chimneys in the framework of a project to monitor their subsidence and tilting during the excavation of a line of the Athens Metro. Geodetic measurements were made under favorable meteorological conditions during four intervals, half to one hour long, during which the wind force 56 in the Beaufort scale velocity was fluctuating from a nearly stable direction, as indicated by recordings of a nearby meteorological station. The output of this study is that during this rather common wind event deflections of the top of the chimney along and across the direction of the wind were above the noise level ...
A cluster of earthquakes (6<Ms <7) characterized by strike slip faulting have occurred alon... more A cluster of earthquakes (6<Ms <7) characterized by strike slip faulting have occurred along the NW edge of the Aegean Arc in the Ionian Sea, the most seismically active region in Greece, in the last 30 years. The most recent earthquake was the 2015 (Mw 6.5) Leucas (Lefkada) earthquake. The modelling of these earthquakes, some of which are double events (2003 Leucas; 2014 Cephalonia) is a challenge for two main reasons. First, the geography of the area limits the distribution of the available seismological and GNSS stations and the correlations of INSAR data. Second, the structural pattern of the area indicates distributed thrusting but recent earthquakes are confined to the west margin of the Aegean Arc, usually assigned to the Cephalonia Transform Fault (CTF), and are dominated by strike slip faulting.
The epicentral area of the 2017, Mw 6.5 destructive Kos-Bodrum normal faulting earthquake, associ... more The epicentral area of the 2017, Mw 6.5 destructive Kos-Bodrum normal faulting earthquake, associated with a small tsunami in a touristic region, is located within the active Gokova graben and represents a case of a previously unrecognized, shallow normal fault without clear geomorphological signature. Analysis of teleseismic body-waveform data and geodetic data, both in the near- and far- field, indicate a well-constrained 25km long and 10km deep south-dipping normal fault which produced small uplift in the Bodrum peninsula. Modeled fault marks the NW edge of the actively extending part of the Gokova graben and was associated with two clusters of aftershocks, while only its eastern part correlates with known active faults. The 2017 earthquake seems to reflect an immature normal fault between Kos Island and the Anatolia mainland, and expansion of the Gokova graben, perhaps through echelon fractures, as is observed in seismic profiles farther east. Activation of normal faults with mo...
Various geophysical problems are described by redundant systems of highly non-linear systems of e... more Various geophysical problems are described by redundant systems of highly non-linear systems of equations with ≥3 unknown variables. Such systems are not possible to be solved with formal algebraic techniques, and are usually solved using sampling methods (mostly Monte Carlo-based), gradual optimization of certain of the unknown variables, a priori fixing of the values of some variables or in the vicinity of approximate solutions. In many cases, especially in the modeling of activated faults or of magma sources from surface displacements, such methods lead to sub-optimal solutions (trapped in local extrema, high uncertainties (trade-off) between certain variables, etc.) and highly influence the understanding/ modeling of certain complex geophysical processes.
Ground settlement above urban tunnels is a threat for nearby buildings, because it may lead to th... more Ground settlement above urban tunnels is a threat for nearby buildings, because it may lead to their differential settlement, tilting, and damage, depending on their structural characteristics, on ground conditions, and on the excavation procedure. Still, for few cases only details on ground settlement are known. In this article we analyze ground subsidence data during the excavation of Lines 2 and 3 of the Athens Metro. Based on this evidence, and in comparison with previous studies, we show that observations of elevation changes and of tilting of buildings may underestimate the amount of ground loss; this is because part of the ground deformation may be compensated by the stiffness of buildings or accommodated by internal deformation of sizeable buildings hosting measuring benchmarks. This effect can be described as static soil–structure interaction (sSSI), in analogy to the dynamic SSI produced during earthquakes. sSSI can produce bias in monitoring data above an advancing tunnel...
SUMMARY Exhaustive searches in regular grids is a traditional and effective method for inversion,... more SUMMARY Exhaustive searches in regular grids is a traditional and effective method for inversion, i.e. numerical solution of systems of non-linear equations which cannot be solved using formal algebraic techniques. However, this technique is effective for very few (3-4) variables and is slow. Recently, the first limitation was to a major degree overpassed with the new TOPological INVersion (TOPINV) algorithm which was used for inversion of systems with up to 18, or even more unknown variables. The novelty of this algorithm is that it is not based on the principle of the mean minimum misfit (cost function) between observations and model predictions, used by most inversion techniques. The new algorithm investigates for each grid-point whether misfits of each observation are within specified uncertainty intervals, and stores clusters of “successful” grid-points in matrix form. These clusters (ensembles, sets) of grid-points are tested whether they satisfy certain criteria and are then ...
Bulletin of the Geological Society of Greece, 2017
The tunnel of Eupalinos at Samos (Greece) is certainly one of the most admirable works in antiqui... more The tunnel of Eupalinos at Samos (Greece) is certainly one of the most admirable works in antiquity, but several questions concerning its plan, and especially the selection of its path, leading to an ‘S’ type curve, a longer tunnel and a longer aqueduct remain without an answer. In this paper we try to provide an answer to the question ‘why Eypalinos selected the specific path for the aqueduct?’ on the basis of geotechnical and geodetic evidence. Two basic criteria should have been satisfied for the tunnel planning: first, that it had to be excavated through rocks with mechanical properties suitable for a safe underground excavation, and second, that the portals should have been in areas permitting accurate geodetic orientation and guidance of the excavation. The overall selection of the tunnel path indicates that Eupalinos had an excellent understanding of the theory of errors and an ability for geological and geotechnical evaluation of the mechanical characteristics of the ground,...
Bulletin of the Geological Society of Greece, 2017
A strong earthquake (Mw 6.9) on 24 May 2014 ruptured the North Aegean Trough (NAT) in Greece, wes... more A strong earthquake (Mw 6.9) on 24 May 2014 ruptured the North Aegean Trough (NAT) in Greece, west of the North Anatolian Fault Zone (NAFZ). In order to provide unbiased constrains of the rupture process and fault geometry of the earthquake, seismological and geodetic data were analyzed independently. First, based on teleseismic long-period P- and SH- waveforms a point-source solution yielded dominantly right-lateral strike-slip faulting mechanism. Furthermore, finite fault inversion of broad-band data revealed the slip history of the earthquake. Second, GPS slip vectors derived from 11 permanent GPS stations uniformly distributed around the meizoseismal area of the earthquake indicated significant horizontal coseismic slip. Inversion of GPS-derived displacements on the basis of Okada model and using the new TOPological INVersion (TOPINV) algorithm permitted to model a vertical strike slip fault, consistent with that derived from seismological data. Obtained results are consistent w...
Abstract A submerged 2300 years-old mole or breakwater with a sigmoidal shape has been identified... more Abstract A submerged 2300 years-old mole or breakwater with a sigmoidal shape has been identified at the Palairos harbor (Akarnania, SW Greece mainland). Different possible scenarios could be proposed to explain this enigmatic shape for an ancient breakwater, such as selective erosion of the original structure, construction above existing shoals or reefs, gravity sliding and post-construction offset due to strike-slip faulting, but all these scenarios seem rather weak. Inspired by a large scale lateral offset of a retaining wall of a quay at the Barcelona harbor due to static liquefaction, by evidence of strike-slip earthquakes and of liquefaction potential in the study area, as well as by recent evidence for long-duration steady, nearly uni-directional dynamic displacements in the near-field of strike-slip faults, we propose an alternative scenario for this mole. An earthquake associated with strike-slip faulting and high acceleration produced liquefaction of the mole foundations and long duration, nearly unidirectional tectonic slip, while the later part of the steady slip produced additional secondary (surficial) slip on liquefied layers.
The plain of Thessaloniki is an important area from a historical standpoint. Numerous reigns and ... more The plain of Thessaloniki is an important area from a historical standpoint. Numerous reigns and empires have occupied the area, leaving behind numerous archaeological remains. The literature and historical evidences show that the city of Pella was located near the sea ...
Understanding the length and subdivisions of ancient length units is necessary for Archaeology, A... more Understanding the length and subdivisions of ancient length units is necessary for Archaeology, Architecture, and engineering, among other fields. These metrological units derive from anthropocentric concepts (fathom, cubit, foot, finger, etc.) and hence their metrological characteristics are variable and unknown for various ancient civilizations. The Roman length units are well determined, but the ancient Greek units are not. A rule sculpted in a metrological relief recently permitted the recognition of the Doric foot as having a length of 327 mm, but the broader use and divisions of this length unit remain unknown. In this article we present evidence of use of the Doric foot from the modeling of an ancient, atypical small theatre of the 4th-3rd century B.C., at Makyneia, on the western Greece mainland. It was found that this structure was designed using the Doric foot and its division in 24 (or even 12) digits. This result from a small provincial town indicates that the Doric foot was in broad use in architectural and engineering works of the ancient Greek World, and this result may be used to solve various problems of that era.
An intermediate depth earthquake sequence with an unusually strong aftershock hit Crete in 1810 a... more An intermediate depth earthquake sequence with an unusually strong aftershock hit Crete in 1810 and was felt in a very broad area. This seismic sequence was believed to have caused a death toll of about 2000-3000 and destroyed a major part of houses in the wider Heraklion area. In this article we present an unpublished note for this earthquake sequence from the memoirs of Frangiskos Limbritis, military and political personality in Crete, and analyze certain other notes from Crete and conclude that the death toll in Heraklion which was mainly affected was of the order of 300 and that structural damage was smaller than what believed in the past and was mostly rapidly repaired, especially in the meizoseismal area which roughly covers the present-day Heraklion prefecture (max intensities VIII-IX).
Geomorphological, petrological, marine, archeological and radiometric case studies of coseismic u... more Geomorphological, petrological, marine, archeological and radiometric case studies of coseismic uplifts or subsidences from Crete and other eastern Mediterranean areas are discussed.
Two sies have been studied: at Mavra Litharia, the uppermost Holocene marine limit is +9.3 m (740... more Two sies have been studied: at Mavra Litharia, the uppermost Holocene marine limit is +9.3 m (7400 yr BP) and uplift rate was betwee 2.9 and 3.5 mm/yr; at Platanos, where the marine limit is above +12.5 m, boring shells at +11.5 m were dated 4800 BP and uplift rate is >2.1-2.7 mm/yr.
In Corfu, two uplifts of 0.8 m occurred, one of them around 790-400 BC. In northern Levkas submer... more In Corfu, two uplifts of 0.8 m occurred, one of them around 790-400 BC. In northern Levkas submergence >=2.5 m occurred since 2400 yr ago and a spasmodic subsidence 500-700 AD. In Cephalonia two seisms occurred around 500-700 AD and in 1953. In soth Zante a 1m coseismic uplift occurred at 200-500 AD.
At least three raised shorelines have been identified at +0.6 , +1.1 and +2.3 m. They are ascribe... more At least three raised shorelines have been identified at +0.6 , +1.1 and +2.3 m. They are ascribed to hintherto unnoticed earthquakes, which occurred approximately 500, 3600-3900 and possibly 1500 years ago.
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Papers by Stathis Stiros