This study presents a new method to analyse the properties of the sea-level signal recorded by co... more This study presents a new method to analyse the properties of the sea-level signal recorded by coastal tide gauges in the long wave range that is in a window between wind/storm waves and tides and is typical of several phenomena like local seiches, coastal shelf resonances and tsunamis. The method consists of computing four specific functions based on the time gradient (slope) of the recorded sea level oscillations, namely the instantaneous slope (IS) as well as three more functions based on IS, namely the reconstructed sea level (RSL), the background slope (BS) and the control function (CF). These functions are examined through a traditional spectral fast Fourier transform (FFT) analysis and also through a statistical analysis, showing that they can be characterised by probability distribution functions PDFs such as the…
Submarine Mass Movements and Their Consequences, 2007
... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Theg... more ... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Thegeometry of the body has been conceived starting from the description by ... De Martini PM, Pantosti D., Palyvos N., Lemeille F., McNeill L., Collier R., 2004, Slip rates of the Aigion ...
TEDA is a real-time algorithm for the detection of potentially dangerous long period waves like t... more TEDA is a real-time algorithm for the detection of potentially dangerous long period waves like tsunamis (Bressan and Tinti, 2011) and it is formed by two simultaneous algorithms built to work at a station level, i.e. on sea level data from a single station: the tsunami detection is designed to identify impulsive long period waves as tsunamis and it triggers a detection when the detided sea level slope exceeds a dynamic threshold that varies according with the previous background sea level slope, while the secure detection triggers an alert when a filtered sea-level signal passes an amplitude threshold. To make TEDA operational in a tide gauge station, both the thresholds of the detection conditions and the temporal parameters in the definitions of TEDA functions should be carefully determined to improve the algorithm efficiency, especially for coastal tide gauge stations that are usually characterized by a local background spectrum and a site dependent tsunami response. This is acc...
<p>The low lying and sandy coastal areas of the Emilia-Roma... more <p>The low lying and sandy coastal areas of the Emilia-Romagna region are heavily threatened by sea storms, often leading to flooding and coastal erosion events with severe impacts on citizens’ quality of life, damages to the cultural heritage and effects on economic activities (e.g. aquaculture, fisheries, tourism, beach facilities). Climate change projections reinforce the need of strategies and tools to prevent damages and promptly react to extreme events. In this context and in the framework of non-structural mitigation measures, the Hydro-Meteo-Climate Service of Arpae Emilia-Romagna (Arpae-SIMC) developed and operationally manages a Coastal Early Warning System (EWS) for the Emilia-Romagna Region (Northeast Italy).</p><p>The EWS was developed during the EU Project FP7-MICORE and it is a state-of-the-art coastal forecasting system that follows a chain of operational numerical models: the meteorological model COSMO, the wave model SWAN-MEDITARE, the ocean model AdriaROMS, and the morphodynamic model XBeach. The latter is currently implemented on a series of cross-shore beach profiles covering eight locations distributed along the Emilia-Romagna shore. Deterministic daily forecasts (72-hours) are generated and Storm Impact Indicators (SIIs) used to assess sea-storm induced coastal risk along the region’s littoral (geo.regione.emilia-romagna.it/schede/ews). </p><p>It is widely known that among the limitations of deterministic approaches, the lack of uncertainty estimation is often problematic as decision-makers might be misled if the only forecast available underestimates (or overestimates) incoming conditions. Hence, following the success of probabilistic forecasting in meteorological applications, storm surge EWSs following ensemble frameworks have been recently developed, allowing for more information available to sustain the decision-making process. Towards the new paradigm change, one of the foreseen outputs of the European Interreg Italy-Croatia CBC Programme project Strategic development of flood management (STREAM) involves the development of a “probabilistic EWS for coastal risk implemented and tested on at least one location along the Emilia-Romagna Coast”. </p><p>The initial implementation of the (semi-)probabilistic framework benefits from the EU ADRION I-STORMS (Integrated Sea Storm Management Strategies) project outcomes, in which wave and sea level multi-model ensembles were developed for the Adriatic Sea giving origin to the Transnational Multi-Model Ensemble (TMES). The TMES was made available as one of the six Integrated Web System (IWS) components, combining five wave and six sea level forecasting systems as means to provide 48-hour forecasts in terms of sea level and wave characteristics (Hs, Tm and Dm). Ensemble mean and standard deviation (SD) are calculated based on different forecasting systems’ results. In the initial approach, four TMES combinations have been tested as XBeach forcing: the TMES mean; the mean minus one SD; the mean plus one SD; the mean plus two SDs. Two months were analyzed together with the already implemented deterministic system for two profiles along the region’s coast.</p><p>The methodology followed for the test period will be shown as well as the results. Furthermore, the methodology under development will be also shown as means to enhance the discussion involving storm surge ensemble applications.</p>
Coastal boulders transported inland by marine hazards, such as tsunamis and storms, are commonly ... more Coastal boulders transported inland by marine hazards, such as tsunamis and storms, are commonly found worldwide. Studies on the transport process of coastal boulders contribute to the understanding of a wide range of phenomena such as high-energy flow events, fluid-structure interaction, and coastal sediments. Consequently, it is crucial to understand how boulders move, but even more important to determine the instability condition for boulder transport. The hydrodynamic formulas including drag and lift coefficients are widely used to predict the incipient motion of boulders while few studies are conducted to evaluate the capability of these formulas. Recently, a series of laboratory experiments carried out at the Hydraulic Engineering Laboratory (Italian acronym LIDR) of the University of Bologna, Italy, revealed that boulders can start moving when the flow height and flow velocity are lower than the theoretical threshold computed by hydraulic formulas. In this paper, we use a num...
At the Hydro-meteo-climate service of the Regional environmental agency of Emilia-Romagna, Italy ... more At the Hydro-meteo-climate service of the Regional environmental agency of Emilia-Romagna, Italy (Arpae-SIMC), the oceanographic numerical model AdriaROMS is used in the operational forecasting suite to compute sea level, temperature, salinity and 3-D current fields of the Adriatic Sea (northern Mediterranean Sea). In order to evaluate the performance of the sea-level forecast and to study different configurations of the ROMS model, two marine storms occurred on the Emilia Romagna coast during the winter 2015–2016 are investigated. <br><br> The main focus of this study is to analyse the sensitivity of the model to the horizontal resolution and to the meteorological forcing. To this end, the model is run with two different configurations and with two horizontal grids at 1 and 2 km resolution. To study the influence of the meteorological forcing, the two storms have been reproduced by running ROMS in ensemble mode, forced by the 16-members of the meteorological ensem...
... Preliminary studies for the ... see Bernard et al., 2006; Developing tsunami-resilient commun... more ... Preliminary studies for the ... see Bernard et al., 2006; Developing tsunami-resilient communities: the National Tsunami Hazard Mitigation Program 2005 ... GITEWS, German-Indonesian TsunamiEarly Warning System, uses an automatic tsunami de-tection algorithm installed in tide ...
http://meetingorganizer.copernicus.org/EGU2009/EGU2009-4376-5.pdf One of the important tasks for ... more http://meetingorganizer.copernicus.org/EGU2009/EGU2009-4376-5.pdf One of the important tasks for the implementation of a tsunami warning system in the Mediterranean Sea is to develop a real-time detection algorithm. Unlike the Mediterranean Sea situation, tsunamis happen quite often in the Pacific Ocean and they have been historically recorded with a proper sampling rate. A large database of tsunami records is therefore available for the Pacific. The Tsunami Research Team of the University of Bologna is developing a real-time detection algorithm on synthetic records. Thanks to the collaboration with NCTR of PMEL/NOAA (NOAA Center for Tsunami Research of Pacific and Marine Environmental Laboratory/National Oceanic and Atmospheric Administration), it has been possible to test this algorithm on specific events recorded by Adak Island tide-gage, in Alaska, and by DART buoys, located offshore Alaska. This work has been undertaken in the framework of the Italian national project DPC-INGV ...
... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Theg... more ... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Thegeometry of the body has been conceived starting from the description by ... De Martini PM, Pantosti D., Palyvos N., Lemeille F., McNeill L., Collier R., 2004, Slip rates of the Aigion ...
This study presents a new method to analyse the properties of the sea-level signal recorded by co... more This study presents a new method to analyse the properties of the sea-level signal recorded by coastal tide gauges in the long wave range that is in a window between wind/storm waves and tides and is typical of several phenomena like local seiches, coastal shelf resonances and tsunamis. The method consists of computing four specific functions based on the time gradient (slope) of the recorded sea level oscillations, namely the instantaneous slope (IS) as well as three more functions based on IS, namely the reconstructed sea level (RSL), the background slope (BS) and the control function (CF). These functions are examined through a traditional spectral fast Fourier transform (FFT) analysis and also through a statistical analysis, showing that they can be characterised by probability distribution functions PDFs such as the…
Submarine Mass Movements and Their Consequences, 2007
... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Theg... more ... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Thegeometry of the body has been conceived starting from the description by ... De Martini PM, Pantosti D., Palyvos N., Lemeille F., McNeill L., Collier R., 2004, Slip rates of the Aigion ...
TEDA is a real-time algorithm for the detection of potentially dangerous long period waves like t... more TEDA is a real-time algorithm for the detection of potentially dangerous long period waves like tsunamis (Bressan and Tinti, 2011) and it is formed by two simultaneous algorithms built to work at a station level, i.e. on sea level data from a single station: the tsunami detection is designed to identify impulsive long period waves as tsunamis and it triggers a detection when the detided sea level slope exceeds a dynamic threshold that varies according with the previous background sea level slope, while the secure detection triggers an alert when a filtered sea-level signal passes an amplitude threshold. To make TEDA operational in a tide gauge station, both the thresholds of the detection conditions and the temporal parameters in the definitions of TEDA functions should be carefully determined to improve the algorithm efficiency, especially for coastal tide gauge stations that are usually characterized by a local background spectrum and a site dependent tsunami response. This is acc...
&amp;amp;amp;lt;p&amp;amp;amp;gt;The low lying and sandy coastal areas of the Emilia-Roma... more &amp;amp;amp;lt;p&amp;amp;amp;gt;The low lying and sandy coastal areas of the Emilia-Romagna region are heavily threatened by sea storms, often leading to flooding and coastal erosion events with severe impacts on citizens&amp;amp;amp;amp;#8217; quality of life, damages to the cultural heritage and effects on economic activities (e.g. aquaculture, fisheries, tourism, beach facilities). Climate change projections reinforce the need of strategies and tools to prevent damages and promptly react to extreme events. In this context and in the framework of non-structural mitigation measures, the Hydro-Meteo-Climate Service of Arpae Emilia-Romagna (Arpae-SIMC) developed and operationally manages a Coastal Early Warning System (EWS) for the Emilia-Romagna Region (Northeast Italy).&amp;amp;amp;lt;/p&amp;amp;amp;gt;&amp;amp;amp;lt;p&amp;amp;amp;gt;The EWS was developed during the EU Project FP7-MICORE and it is a state-of-the-art coastal forecasting system that follows a chain of operational numerical models: the meteorological model COSMO, the wave model SWAN-MEDITARE, the ocean model AdriaROMS, and the morphodynamic model XBeach. The latter is currently implemented on a series of cross-shore beach profiles covering eight locations distributed along the Emilia-Romagna shore. Deterministic daily forecasts (72-hours) are generated and Storm Impact Indicators (SIIs) used to assess sea-storm induced coastal risk along the region&amp;amp;amp;amp;#8217;s littoral (geo.regione.emilia-romagna.it/schede/ews).&amp;amp;amp;amp;#160;&amp;amp;amp;lt;/p&amp;amp;amp;gt;&amp;amp;amp;lt;p&amp;amp;amp;gt;It is widely known that among the limitations of deterministic approaches, the lack of uncertainty estimation is often problematic as decision-makers might be misled if the only forecast available underestimates (or overestimates) incoming conditions. Hence, following the success of probabilistic forecasting in meteorological applications, storm surge EWSs following ensemble frameworks have been recently developed, allowing for more information available to sustain the decision-making process. Towards the new paradigm change, one of the foreseen outputs of the European Interreg Italy-Croatia CBC Programme project Strategic development of flood management (STREAM) involves the development of a &amp;amp;amp;amp;#8220;probabilistic EWS for coastal risk implemented and tested on at least one location along the Emilia-Romagna Coast&amp;amp;amp;amp;#8221;.&amp;amp;amp;amp;#160;&amp;amp;amp;lt;/p&amp;amp;amp;gt;&amp;amp;amp;lt;p&amp;amp;amp;gt;The initial implementation of the (semi-)probabilistic framework benefits from the EU ADRION I-STORMS (Integrated Sea Storm Management Strategies) project outcomes, in which wave and sea level multi-model ensembles were developed for the Adriatic Sea giving origin to the Transnational Multi-Model Ensemble (TMES). The TMES was made available as one of the six Integrated Web System (IWS) components, combining five wave and six sea level forecasting systems as means to provide 48-hour forecasts in terms of sea level and wave characteristics (Hs, Tm and Dm). Ensemble mean and standard deviation (SD) are calculated based on different forecasting systems&amp;amp;amp;amp;#8217; results. In the initial approach, four TMES combinations have been tested as XBeach forcing: the TMES mean; the mean minus one SD; the mean plus one SD; the mean plus two SDs. Two months were analyzed together with the already implemented deterministic system for two profiles along the region&amp;amp;amp;amp;#8217;s coast.&amp;amp;amp;lt;/p&amp;amp;amp;gt;&amp;amp;amp;lt;p&amp;amp;amp;gt;The methodology followed for the test period will be shown as well as the results. Furthermore, the methodology under development will be also shown as means to enhance the discussion involving storm surge ensemble applications.&amp;amp;amp;lt;/p&amp;amp;amp;gt;
Coastal boulders transported inland by marine hazards, such as tsunamis and storms, are commonly ... more Coastal boulders transported inland by marine hazards, such as tsunamis and storms, are commonly found worldwide. Studies on the transport process of coastal boulders contribute to the understanding of a wide range of phenomena such as high-energy flow events, fluid-structure interaction, and coastal sediments. Consequently, it is crucial to understand how boulders move, but even more important to determine the instability condition for boulder transport. The hydrodynamic formulas including drag and lift coefficients are widely used to predict the incipient motion of boulders while few studies are conducted to evaluate the capability of these formulas. Recently, a series of laboratory experiments carried out at the Hydraulic Engineering Laboratory (Italian acronym LIDR) of the University of Bologna, Italy, revealed that boulders can start moving when the flow height and flow velocity are lower than the theoretical threshold computed by hydraulic formulas. In this paper, we use a num...
At the Hydro-meteo-climate service of the Regional environmental agency of Emilia-Romagna, Italy ... more At the Hydro-meteo-climate service of the Regional environmental agency of Emilia-Romagna, Italy (Arpae-SIMC), the oceanographic numerical model AdriaROMS is used in the operational forecasting suite to compute sea level, temperature, salinity and 3-D current fields of the Adriatic Sea (northern Mediterranean Sea). In order to evaluate the performance of the sea-level forecast and to study different configurations of the ROMS model, two marine storms occurred on the Emilia Romagna coast during the winter 2015–2016 are investigated. <br><br> The main focus of this study is to analyse the sensitivity of the model to the horizontal resolution and to the meteorological forcing. To this end, the model is run with two different configurations and with two horizontal grids at 1 and 2 km resolution. To study the influence of the meteorological forcing, the two storms have been reproduced by running ROMS in ensemble mode, forced by the 16-members of the meteorological ensem...
... Preliminary studies for the ... see Bernard et al., 2006; Developing tsunami-resilient commun... more ... Preliminary studies for the ... see Bernard et al., 2006; Developing tsunami-resilient communities: the National Tsunami Hazard Mitigation Program 2005 ... GITEWS, German-Indonesian TsunamiEarly Warning System, uses an automatic tsunami de-tection algorithm installed in tide ...
http://meetingorganizer.copernicus.org/EGU2009/EGU2009-4376-5.pdf One of the important tasks for ... more http://meetingorganizer.copernicus.org/EGU2009/EGU2009-4376-5.pdf One of the important tasks for the implementation of a tsunami warning system in the Mediterranean Sea is to develop a real-time detection algorithm. Unlike the Mediterranean Sea situation, tsunamis happen quite often in the Pacific Ocean and they have been historically recorded with a proper sampling rate. A large database of tsunami records is therefore available for the Pacific. The Tsunami Research Team of the University of Bologna is developing a real-time detection algorithm on synthetic records. Thanks to the collaboration with NCTR of PMEL/NOAA (NOAA Center for Tsunami Research of Pacific and Marine Environmental Laboratory/National Oceanic and Atmospheric Administration), it has been possible to test this algorithm on specific events recorded by Adak Island tide-gage, in Alaska, and by DART buoys, located offshore Alaska. This work has been undertaken in the framework of the Italian national project DPC-INGV ...
... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Theg... more ... The sliding body has been hypothesized to detach from close to the shoreline (Figure 2). Thegeometry of the body has been conceived starting from the description by ... De Martini PM, Pantosti D., Palyvos N., Lemeille F., McNeill L., Collier R., 2004, Slip rates of the Aigion ...
ABSTRACT TEDA is a real-time algorithm for the detection of potentially dangerous long period wav... more ABSTRACT TEDA is a real-time algorithm for the detection of potentially dangerous long period waves like tsunamis (Bressan and Tinti, 2011) and it is formed by two simultaneous algorithms built to work at a station level, i.e. on sea level data from a single station: the tsunami detection is designed to identify impulsive long period waves as tsunamis and it triggers a detection when the detided sea level slope exceeds a dynamic threshold that varies according with the previous background sea level slope, while the secure detection triggers an alert when a filtered sea-level signal passes an amplitude threshold. To make TEDA operational in a tide gauge station, both the thresholds of the detection conditions and the temporal parameters in the definitions of TEDA functions should be carefully determined to improve the algorithm efficiency, especially for coastal tide gauge stations that are usually characterized by a local background spectrum and a site dependent tsunami response. This is accomplished by a performance evaluation study, called calibration, which consists in the analysis of the performance of TEDA tested a posteriori with different settings on available data, both on background condition and in case of tsunami event. The study of the background signal and in particular of the potential dangerous events that can affect the site is very important, especially in case of no tsunami records available, where synthetic tsunami signals produced by numerical simulations of known and possible tsunamigenic sources should be used. The calibration of TEDA in a specific site allows not only to optimize, but also to evaluate its efficiency in different possible situations. In this work we present the results of TEDA calibration for two Italian sites, Catania and Tremestieri, both on the eastern coast of Sicily, where coastal tide gauges are installed, with synthetic tsunami signals from tsunami scenarios, including seismic and landslide sources (Tonini et al, 2011).
One of the important tasks for the implementation of a tsunami warning system in the Mediterranea... more One of the important tasks for the implementation of a tsunami warning system in the Mediterranean Sea is to develop a real-time detection algorithm. Unlike the Mediterranean Sea situation, tsunamis happen quite often in the Pacific Ocean and they have been historically recorded with a proper sampling rate. A large database of tsunami records is therefore available for the Pacific. The Tsunami Research Team of the University of Bologna is developing a real-time detection algorithm on synthetic records. Thanks to the collaboration with NCTR of PMEL/NOAA (NOAA Center for Tsunami Research of Pacific and Marine Environmental Laboratory/National Oceanic and Atmospheric Administration), it has been possible to test this algorithm on specific events recorded by Adak Island tide-gage, in Alaska, and by DART buoys, located offshore Alaska. This work has been undertaken in the framework of the Italian national project DPC-INGV S3. The detection algorithm has the goal to discriminate the first tsunami wave from the previous background signal. Shortly, the algorithm is built on a parameter based on the standard deviation of the signal calculated on a short time window and on its comparison with its computed prediction through a control function. The control function indicates a tsunami detection whenever it exceeds a certain threshold. The algorithm was calibrated and tested both on coastal tide-gages and on offshore buoys that measure sea-level changes. Its calibration presents different issues if the algorithm has to be implemented on an offshore buoy or on a coastal tide-gage. In particular, the algorithm parameters are site-specific for coastal sea-level signals, because sea-level changes are here mainly characterized by oscillations induced by the coastal topography. Adak Island background signal was analyzed and the algorithm parameters were set: It was found that there is a persistent presence of seiches with periods in the tsunami range, to which the algorithm is also sensible. To safely detect a tsunami it is needed to target the algorithm only on tsunamis of bigger amplitude than seiches. Offshore sea-level signal is mainly composed by white noise and the tide. The main issue is that the tsunami signal may not have a very large amplitude respect to noise. However, if the buoy is located near the tsunami source, the seismic signal is very large and hides completely the tsunami signal. With the calibration and the test of the algorithm, a method to distinguish a seismic signal from a tsunami one was also studied.
The tsunamigenic earthquake (M 8.8) that occurred offshore central Chile on 27 February 2010 can ... more The tsunamigenic earthquake (M 8.8) that occurred offshore central Chile on 27 February 2010 can be classified as a typical subduction-zone earthquake. The effects of the ensuing tsunami have been devastating along the Chile coasts, and especially between the cities of Valparaiso and Talcahuano, and in the Juan Fernandez islands. The tsunami propagated across the entire Pacific Ocean, hitting with variable intensity almost all the coasts facing the basin. While the far-field propagation was quite well tracked almost in real-time by the warning centres and reasonably well reproduced by the forecast models, the toll of lives and the severity of the damage caused by the tsunami in the near-field occurred with no local alert nor warning and sadly confirms that the protection of the communities placed close to the tsunami sources is still an unresolved problem in the tsunami early warning field. The purpose of this study is two-fold. On one side we perform numerical simulations of the tsunami starting from different earthquake models which we built on the basis of the preliminary seismic parameters (location, magnitude and focal mechanism) made available by the seismological agencies immediately after the event, or retrieved from more detailed and refined studies published online in the following days and weeks. The comparison with the available records of both offshore DART buoys and coastal tide-gauges is used to put some preliminary constraints on the best-fitting fault model. The numerical simulations are performed by means of the finite-difference code UBO-TSUFD, developed and maintained by the Tsunami Research Team of the University of Bologna, Italy, which can solve both the linear and non-linear versions of the shallow-water equations on nested grids. The second purpose of this study is to use the conclusions drawn in the previous part in a tsunami early warning perspective. In the framework of the EU-funded project DEWS (Distant Early Warning System), we will try to give some clues for discussion on the deficiencies of the existing tsunami early warning concepts as regards the warning to the areas which are found close to the tsunami source, and on the strategies that should be followed in the near future in order to make significant progress in the protection and safeguarding of local communities.
Tsunami detection in real-time, both offshore and at the coastline, plays a key role in Tsunami W... more Tsunami detection in real-time, both offshore and at the coastline, plays a key role in Tsunami Warning Systems since it provides so far the only reliable and timely proof of tsunami generation, and is used to confirm or cancel tsunami warnings previously issued on the basis of seismic data alone. Moreover, in case of submarine or coastal landslide generated tsunamis, which are not announced by clear seismic signals and are typically local, real-time detection at the coastline might be the fastest way to release a warning, even if the useful time for emergency operations might be limited. TEDA is an algorithm for real-time detection of tsunami signal on sea-level records, developed by the Tsunami Research Team of the University of Bologna. The development and testing of the algorithm has been accomplished within the framework of the Italian national project DPC-INGV S3 and the European project TRANSFER. The algorithm is to be implemented at station level, and it is based therefore only on sea-level data of a single station, either a coastal tide-gauge or an offshore buoy. TEDA's principle is to discriminate the first tsunami wave from the previous background signal, which implies the assumption that the tsunami waves introduce a difference in the previous sea-level signal. Therefore, in TEDA the instantaneous (most recent) and the previous background sea-level elevation gradients are characterized and compared by proper functions (IS and BS) that are updated at every new data acquisition. Detection is triggered when the instantaneous signal function passes a set threshold and at the same time it is significantly bigger compared to the previous background signal. The functions IS and BS depend on temporal parameters that allow the algorithm to be adapted different situations: in general, coastal tide-gauges have a typical background spectrum depending on the location where the instrument is installed, due to local topography and bathymetry, while offshore buoys are mainly characterized by the astronomical tide and white noise. TEDA has been tested on specific events recorded by Adak Island tide-gauge, in Alaska, and by DART buoys, located offshore Alaska, thanks to the collaboration with NCTR of PMEL/NOAA (NOAA Centre for Tsunami Research of Pacific and Marine Environmental Laboratory/National Oceanic and Atmospheric Administration). Three methods for the characterization of the background signal have been tested and compared with different characterization settings, in order to find the most appropriate calibration. To evaluate the algorithm performance, different indicators have been taken into account, such as the number of false detections, the number of events detected, the delay of detection and the duration of the tsunami alert state. Particular attention has been reserved to the number of false detections, which compromise heavily the reliability of a detection algorithm and undermine the usefulness of the algorithm itself. The method to test TEDA is presented here and is proposed as an example of procedure to evaluate the performance of the tsunami detection algorithms used in the Tsunami Early Warning Systems practice.
Uploads