scholarly journals THE GREEK CATALOGUE OF ACTIVE FAULTS AND DATABASE OF SEISMOGENIC SOURCES

2017 ◽  
Vol 43 (1) ◽  
pp. 486 ◽  
Author(s):  
S. Pavlides ◽  
R. Caputo ◽  
S. Sboras ◽  
A. Chatzipetros ◽  
G. Papathanasiou ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Active Faults ◽  
Geophysical Data ◽  
Aegean Area ◽  
Aegean Region ◽  
Seismogenic Sources ◽  
Available Information ◽  
Different Sources ◽  
Systematic Collection ◽  
Of Greece

The new reasearch project to create the Greek Catalogue of Active Faults and Database of Seismogenic Sources has three major goals: (i) the systematic collection of all available information concerning neotectonic, active and capable faults as well as broader seismogenic volumes within the Aegean Region; the search will be mainly based on geological and geophysical data; (ii) the quantification of the principal seismotectonic parameters of the different sources and the associated degree of uncertainty; (iii) to supply an integrated view of potentially damaging seismogenic sources for a better assessment of the Seismic Hazard of Greece. The informatic framework of the database follows that used for the Italian Database of Individual Seismogenic Sources (DISS). In this paper we present the architecture of the new Database of Active faults of the broader Aegean Area relative to Greece, the progress made up to present and the following activities yet to be accomplished.

scholarly journals Time independent seismic hazard analysis of Greece deduced from Bayesian statistics

2003 ◽  
Vol 3 (1/2) ◽  
pp. 129-134 ◽  
Author(s):  
T. M. Tsapanos ◽  
G. A. Papadopoulos ◽  
O. Ch. Galanis
Keyword(s):  
Seismic Hazard ◽  
Bayesian Statistics ◽  
Hazard Analysis ◽  
Earthquake Occurrence ◽  
Time Intervals ◽  
Seismogenic Sources ◽  
Earthquake Resistant Design ◽  
Seismogenic Source ◽  
Earthquake Resistant ◽  
Of Greece

Abstract. A Bayesian statistics approach is applied in the seismogenic sources of Greece and the surrounding area in order to assess seismic hazard, assuming that the earthquake occurrence follows the Poisson process. The Bayesian approach applied supplies the probability that a certain cut-off magnitude of Ms = 6.0 will be exceeded in time intervals of 10, 20 and 75 years. We also produced graphs which present the different seismic hazard in the seismogenic sources examined in terms of varying probability which is useful for engineering and civil protection purposes, allowing the designation of priority sources for earthquake-resistant design. It is shown that within the above time intervals the seismogenic source (4) called Igoumenitsa (in NW Greece and west Albania) has the highest probability to experience an earthquake with magnitude M > 6.0. High probabilities are found also for Ochrida (source 22), Samos (source 53) and Chios (source 56).

scholarly journals Geologic and geodetic constraints on the seismic hazard of Malawi’s active faults: The Malawi Seismogenic Source Database (MSSD)

2021 ◽  
Author(s):  
Jack N. Williams ◽  
Luke N. J. Wedmore ◽  
Åke Fagereng ◽  
Maximilian J. Werner ◽  
Hassan Mdala ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Active Fault ◽  
Active Faults ◽  
Slip Rate ◽  
Slip Rates ◽  
Source Database ◽  
Seismogenic Sources ◽  
Seismogenic Source ◽  
Recurrence Intervals ◽  
Seismic Reflector

Abstract. Active fault data are commonly used in seismic hazard assessments, but there are challenges in deriving the slip rate, geometry, and frequency of earthquakes along active faults. Herein, we present the open-access geospatial Malawi Seismogenic Source Database (MSSD), which describes the seismogenic properties of faults that have formed during East African rifting in Malawi. We first use empirical observations to geometrically classify active faults into section, fault, and multi-fault seismogenic sources. For sources in the North Basin of Lake Malawi, slip rates can be derived from the vertical offset of a seismic reflector that is estimated to be 75 ka based on dated core. Elsewhere, slip rates are constrained from advancing a ‘systems-based’ approach that partitions geodetically-derived rift extension rates in Malawi between seismogenic sources using a priori constraints on regional strain distribution in magma-poor continental rifts. Slip rates are then combined with source geometry and empirical scaling relationships to estimate earthquake magnitudes and recurrence intervals, and their uncertainty is described from the variability of outcomes from a logic tree used in these calculations. We find that for sources in the Lake Malawi’s North Basin, where slip rates can be derived from both the geodetic data and the offset seismic reflector, the slip rate estimates are within error of each other, although those from the offset reflector are higher. Sources in the MSSD are 5–200 km long, which implies that large magnitude (MW 7–8) earthquakes may occur in Malawi. Low slip rates (0.05–2 mm/yr), however, mean that the frequency of such events will be low (recurrence intervals ~103–104 years). The MSSD represents an important resource for investigating Malawi’s increasing seismic risks and provides a framework for incorporating active fault data into seismic hazard assessment in other tectonically active regions.

scholarly journals SEISMOGENIC SOURCES IN THE AEGEAN AREA AND THEIR PREDICTIVE PROPERTIES

2017 ◽  
Vol 50 (3) ◽  
pp. 1222 ◽  
Author(s):  
B.C. Papazachos ◽  
G.F. Karakaisis ◽  
E.M. Scordilis ◽  
Ch. Papaioannou
Keyword(s):  
Test Data ◽  
Regional Model ◽  
Aegean Area ◽  
Seismogenic Sources ◽  
Joint Application ◽  
Complete Catalogue ◽  
Available Information ◽  
Seismicity Model ◽  
Catalogue Of Earthquakes

On the basis of all available information eight circular seismogenic sources, where shallow (h 100km) earthquakes occur, are defined in the broader Aegean area. The location of each source is further improved by optimization of the quasi-periodic properties of the strong (M≥6.0) instrumentally recorded mainshocks, identified in a complete catalogue of earthquakes (1911-2014) after declustering. Moreover, in the same seismogenic sources, all M≥6.3 mainshocks that comprise another complete catalogue (1850-2014) have also occurred. Interevent times of mainshocks generated in each source have predictive properties expressed by the TIMAPR (Time and Magnitude Predictable Regional) model whereas preshocks of recent mainshocks have also such properties expressed by the D-AS (Decelerating-Accelerating Seismicity) model. Retrospective prediction of the last mainshock in each source by the joint application of the two models resulted in reasonable uncertainties. Then, as a forward test, data up to the end of 2014 were used to predict the next expected mainshock in each of the eight sources and to identify the fault where its epicentre will probably be located.

scholarly journals A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

2013 ◽  
Vol 1 (6) ◽  
pp. 6719-6784 ◽  
Author(s):  
D. A. Vamvakaris ◽  
C. B. Papazachos ◽  
C. Papaioannou ◽  
E. M. Scordilis ◽  
G. F. Karakaisis
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Maximum Magnitude ◽  
Seismic Zone ◽  
Seismic Zonation ◽  
Aegean Area ◽  
Seismic Zones ◽  
Shallow Earthquakes

Abstract. In the present work we present an effort to define a new seismic zonation model of area type sources for the broader Aegean area, which can be readily used for seismic hazard assessment. The definition of this model is based not only on seismicity information but incorporates all available seismotectonic and neotectonic information available for the study area, in an attempt to define zones which show not only a rather homogeneous seismicity release but also exhibit similar active faulting characteristics. For this reason, all available seismological information such as fault plane solutions and the corresponding kinematic axes have been incorporated in the analysis, as well as information about active tectonics, such as seismic and active faults. Moreover, various morphotectonic features (e.g. relief, coastline) were also considered. Finally, a revised seismic catalogue is employed and earthquake epicentres since historical times (550 BC–2008) are considered, in order to define areas of common seismotectonic characteristics, that could constitute a discrete seismic zone. A new revised model of 113 earthquake seismic zones of shallow earthquakes for the broader Aegean area is finally proposed. Using the proposed zonation model, a detailed study is performed for the catalogue completeness for the recent instrumental period. Using the defined completeness information, seismicity parameters (such as G–R values) for the 113 new seismic zones have been calculated, and their spatial distribution was also examined. The spatial variation of the obtained b values shows an excellent correlation with the geotectonic setting in the area, in good agreement with previous studies. Moreover, a quantitative estimation of seismicity is performed in terms of the mean return period, Tm, of large (M ≥ 6.0) earthquakes, as well as the most frequent maximum magnitude, Mt, for a typical time period (T = 50 yr), revealing significant spatial variations of seismicity levels within the study area. The new proposed seismic zonation model and its parameters can be readily employed for seismic hazard assessment for the broader Aegean area.

scholarly journals Fossil landscapes and youthful seismogenic sources in the central Apennines: excerpts from the 24 August 2016, Amatrice earthquake and seismic hazard implications

2016 ◽  
Vol 59 ◽  
Author(s):  
Gianluca Valensise ◽  
Paola Vannoli ◽  
Roberto Basili ◽  
Lorenzo Bonini ◽  
Pierfrancesco Burrato ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Active Faults ◽  
Upper Crust ◽  
Central Apennines ◽  
Great Caution ◽  
Seismogenic Sources ◽  
Seismogenic Faults ◽  
2016 Amatrice Earthquake

<p><em>We show and discuss the similarities among the 2016 Amatrice (Mw 6.0), 1997 Colfiorito-Sellano (Mw 6.0-5.6) and 2009 L’Aquila (Mw 6.3) earthquakes. They all occurred along the crest of the central Apennines and were caused by shallow dipping faults between 3 and 10 km depth, as shown by their characteristic InSAR signature. We contend that these earthquakes delineate a seismogenic style that is characteristic of this portion of the central Apennines, where the upward propagation of seismogenic faults is hindered by the presence of pre-existing regional thrusts. This leads to an effective decoupling between the deeper seismogenic portion of the upper crust and its uppermost 3 km.The decoupling implies that active faults mapped at the surface do not connect with the seismogenic sources, and that their evolution may be controlled by passive readjustments to coseismic strains or even by purely gravitational motions. Seismic hazard analyses and estimates based on such faults should hence be considered with great caution as they may be all but representative of the true seismogenic potential.</em></p><em></em>

scholarly journals A detailed seismic zonation model for shallow earthquakes in the broader Aegean area

2016 ◽  
Vol 16 (1) ◽  
pp. 55-84 ◽  
Author(s):  
D. A. Vamvakaris ◽  
C. B. Papazachos ◽  
Ch. A. Papaioannou ◽  
E. M. Scordilis ◽  
G. F. Karakaisis
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Maximum Magnitude ◽  
Seismic Zone ◽  
Seismic Zonation ◽  
Aegean Area ◽  
Seismic Zones ◽  
Shallow Earthquakes

Abstract. In the present work we propose a new seismic zonation model of area type sources for the broader Aegean area, which can be readily used for seismic hazard assessment. The definition of this model is based not only on seismicity information but incorporates all available seismotectonic and neotectonic information for the study area, in an attempt to define zones which show not only a rather homogeneous seismicity release but also exhibit similar active faulting characteristics. For this reason, all available seismological information such as fault plane solutions and the corresponding kinematic axes have been incorporated in the analysis, as well as information about active tectonics, such as seismic and active faults. Moreover, various morphotectonic features (e.g. relief, coastline) were also considered. Finally, a revised seismic catalogue is employed and earthquake epicentres since historical times (550 BC–2008) are employed, in order to define areas of common seismotectonic characteristics, that could constitute a discrete seismic zone. A new revised model of 113 earthquake seismic zones of shallow earthquakes for the broader Aegean area is finally proposed. Using the proposed zonation model, a detailed study is performed for the catalogue completeness for the recent instrumental period.Using the defined completeness information, seismicity parameters (such as G–R values) for the 113 new seismic zones have been calculated, and their spatial distribution was also examined. The spatial variation of the obtained b values shows an excellent correlation with the geotectonic setting in the area, in good agreement with previous studies. Moreover, a quantitative estimation of seismicity is performed in terms of the mean return period, Tm, of large (M  ≥  6.0) earthquakes, as well as the most frequent maximum magnitude, Mt, for a typical time period (T  =  50 yr), revealing significant spatial variations of seismicity levels within the study area. The new proposed seismic zonation model and its parameters can be readily employed for seismic hazard assessment for the broader Aegean area.

scholarly journals Bayesian probabilities for occurrence of large earthquakes in the seismogenic sources of Japan and Phillipine during the period 1998-2017

2001 ◽  
Vol 34 (4) ◽  
pp. 1619
Author(s):  
T. M. TSAPANOS ◽  
O. CH. GALANIS ◽  
S. D. MAVRIDOU ◽  
M. P. HELMl
Keyword(s):  
Seismic Hazard ◽  
Bayesian Statistics ◽  
Poisson Distribution ◽  
Bayesian Approach ◽  
Seismic Sources ◽  
Time Interval ◽  
Seismogenic Sources ◽  
The One ◽  
Large Earthquakes ◽  
The Bayesian Approach

The Bayesian statistics is adopted in 11 seismic sources of Japan and 14 of Philippine in order to estimate the probabilities of occurrence of large future earthquakes, assuming that earthquakes occurrence follows the Poisson distribution. The Bayesian approach applied represents the probability that a certain cut-off magnitude (or larger) will exceed in a given time interval of 20 years, that is 1998-2017. This cut-off magnitude is chosen the one with M=7.0 or greater. In this case we can consider these obtained probabilities as a seismic hazard presentation. More over curves are produced which present the fluctuation of the seismic hazard between these seismic sources. These graphs of varying probability are useful either for engineering or other practical purposes

scholarly journals Tectonic Geomorphology and Paleoseismology of the Sharkhai fault: a new source of seismic hazard for Ulaanbaatar (Mongolia)

2021 ◽  
Author(s):  
Abeer Al-Ashkar ◽  
Antoine Schlupp ◽  
Matthieu Ferry ◽  
Ulziibat Munkhuu
Keyword(s):  
Seismic Hazard ◽  
Scaling Laws ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Capital City ◽  
Tectonic Geomorphology ◽  
Time Interval ◽  
Coseismic Slip ◽  
Slip Rates ◽  
Large Earthquakes

Abstract. We present new constraints from tectonic geomorphology and paleoseismology along the newly discovered Sharkhai fault near the capital city of Mongolia. Detailed observations from high resolution Pleiades satellite images and field investigations allowed us to map the fault in detail, describe its geometry and segmentation, characterize its kinematics, and document its recent activity and seismic behavior (cumulative displacements and paleoseismicity). The Sharkhai fault displays a surface length of ~40 km with a slightly arcuate geometry, and a strike ranging from N42° E to N72° E. It affects numerous drainages that show left-lateral cumulative displacements reaching 57 m. Paleoseismic investigations document the faulting and deposition record for the last ~3000 yr and reveal that the penultimate earthquake (PE) occurred between 1515 ± 90 BC and 945 ± 110 BC and the most recent event (MRE) occurred after 860 ± 85 AD. The resulting time interval of 2080 ± 470 years is the first constraint on the Sharkhai fault for large earthquakes. On the basis of our mapping of the surface rupture and the resulting segmentation analysis, we propose two possible scenarios for large earthquakes with likely magnitudes between 6.4 ± 0.2 and 7.1 ± 0.2. Furthermore, we apply scaling laws to infer coseismic slip values and derive preliminary estimates of long-term slip rates between 0.2 ± 0.2 and 1.0 ± 0.5 mm/y. Finally, we propose that these original observations and results from a newly discovered fault should be taken into account for the seismic hazard assessment for the city of Ulaanbaatar and help build a comprehensive model of active faults in that region.

An Assessment of Earthquake Scaling Relationships for Crustal Earthquakes in Indonesia

2021 ◽  
Author(s):  
Endra Gunawan
Keyword(s):  
Seismic Hazard ◽  
Active Faults ◽  
Hazard Model ◽  
Strike Slip ◽  
Coseismic Deformation ◽  
Maximum Magnitude ◽  
Scaling Relationships ◽  
Rupture Length ◽  
Scaling Relationship ◽  
Earthquake Scaling

Abstract To estimate the hazard posed by active faults, estimates of the maximum magnitude earthquake that could occur on the fault are needed. I compare previously published scaling relationships between earthquake magnitude and rupture length with data from recent earthquakes in Indonesia. I compile a total amount of 13 literatures on investigating coseismic deformation in Indonesia, which then divided into strike-slip and dip-slip earthquake cases. I demonstrate that a different scaling relationship generates different misfit compared to data. For a practical practice of making seismic hazard model in Indonesia, this research shows the suggested reference for a scaling relationship of strike-slip and dip-slip faulting regime. On a practical approach in constructing a logic tree for seismic hazard model, using different weighting between each published earthquake scaling relationship is recommended.

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