scholarly journals Approach for combining faults and area sources in seismic hazard assessment: Application in southeastern Spain

2018 ◽  
Author(s):  
Alicia Rivas-Medina ◽  
Belén Benito ◽  
Jorge Miguel Gaspar-Escribano
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Methodological Approach ◽  
Hybrid Approach ◽  
Seismic Hazard Assessment ◽  
Source Model ◽  
Zone Model ◽  
Maximum Magnitude ◽  
Seismic Potential ◽  
Gnss Measurements

Abstract. This paper presents a methodological approach for seismic hazard assessment that considers a hybrid source model composed by faults as independent entities and zones (containing the residual seismicity). The seismic potential of both types of sources is derived from different data: for the zones, the recurrence model is estimated from the seismic catalog. For fault sources, it is inferred from kinematic parameters derived from paleoseismicty and GNSS measurements. Distributing the seismic potential associated to each source is a key question when considering hybrid models of zone and faults, which some authors solve by assigning to the fault only the earthquakes that exceed a fixed magnitude value Mc. In the present approach, instead of restricting the magnitudes of each type of source, the distribution of seismic potential is carried out only for magnitudes below the maximum magnitude value completely recorded in the catalog (Mmaxc). This is derived from a completeness analysis and can be lower than the Mmax generated by the faults, taking into account that their the recurrence period can be higher than the observation period of the catalog. The proposed approach is applied in southern Spain, a region of low-to-moderate seismic where faults move slowly. The results obtained are contrasted with the results of a seismic hazard model using the traditional zone model exclusively. Results show a concentration of expected accelerations around fault traces using the hybrid approach, which is not appreciated in the classic approach using zones exclusively.

scholarly journals Approach for combining fault and area sources in seismic hazard assessment: application in south-eastern Spain

2018 ◽  
Vol 18 (11) ◽  
pp. 2809-2823 ◽  
Author(s):  
Alicia Rivas-Medina ◽  
Belen Benito ◽  
Jorge Miguel Gaspar-Escribano
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Methodological Approach ◽  
Hybrid Approach ◽  
Seismic Hazard Assessment ◽  
Source Model ◽  
Zone Model ◽  
Essential Difference ◽  
Seismic Potential ◽  
Moderate Seismicity

Abstract. This paper presents a methodological approach to seismic hazard assessment based on a hybrid source model composed of faults as independent entities and zones containing residual seismicity. The seismic potential of both types of sources is derived from different data: for the zones, the recurrence model is estimated from the seismic catalogue. For fault sources, it is inferred from slip rates derived from palaeoseismicity and GNSS (Global Navigation Satellite System) measurements. Distributing the seismic potential associated with each source is a key question when considering hybrid zone and fault models, and this is normally resolved using one of two possible alternatives: (1) considering a characteristic earthquake model for the fault and assigning the remaining magnitudes to the zone, or (2) establishing a cut-off magnitude, Mc, above which the seisms are assigned to the fault and below which they are considered to have occurred in the zone. This paper presents an approach to distributing seismic potential between zones and faults without restricting the magnitudes for each type of source, precluding the need to establish cut-off Mc values beforehand. This is the essential difference between our approach and other approaches that have been applied previously. The proposed approach is applied in southern Spain, a region of low-to-moderate seismicity where faults move slowly. The results obtained are contrasted with the results of a seismic hazard method based exclusively on the zone model. Using the hybrid approach, acceleration values show a concentration of expected accelerations around fault traces, which is not appreciated in the classic approach using only zones.

scholarly journals A seismic source zone model for the seismic hazard assessment of Slovakia

2016 ◽  
Vol 67 (3) ◽  
pp. 275-290 ◽  
Author(s):  
Jozef Hók ◽  
Robert Kysel ◽  
Michal Kováč ◽  
Peter Moczo ◽  
Jozef Kristek ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Large Scale ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Source Zone ◽  
Zone Model ◽  
Geological Structures ◽  
Seismotectonic Model ◽  
Seismogenic Structures

Abstract We present a new seismic source zone model for the seismic hazard assessment of Slovakia based on a new seismotectonic model of the territory of Slovakia and adjacent areas. The seismotectonic model has been developed using a new Slovak earthquake catalogue (SLOVEC 2011), successive division of the large-scale geological structures into tectonic regions, seismogeological domains and seismogenic structures. The main criteria for definitions of regions, domains and structures are the age of the last tectonic consolidation of geological structures, thickness of lithosphere, thickness of crust, geothermal conditions, current tectonic regime and seismic activity. The seismic source zones are presented on a 1:1,000,000 scale map.

scholarly journals Planar Seismic Source Characterization Models Developed for Probabilistic Seismic Hazard Assessment of Istanbul

2017 ◽  
Author(s):  
Zeynep Gülerce ◽  
Kadir Buğra Soyman ◽  
Barış Güner ◽  
Nuretdin Kaymakci
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Model Parameters ◽  
Probabilistic Seismic Hazard ◽  
Maximum Magnitude ◽  
Source Characterization ◽  
Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of North Anatolian Fault Zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of 1999 Kocaeli and Düzce earthquakes, Central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that associated with the rupture system. Uncertainty in the SSC model parameters (e.g. b-value, maximum magnitude, weights of the rupture scenarios) is considered in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully-documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

scholarly journals Planar seismic source characterization models developed for probabilistic seismic hazard assessment of Istanbul

2017 ◽  
Vol 17 (12) ◽  
pp. 2365-2381 ◽  
Author(s):  
Zeynep Gülerce ◽  
Kadir Buğra Soyman ◽  
Barış Güner ◽  
Nuretdin Kaymakci
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Model Parameters ◽  
Probabilistic Seismic Hazard ◽  
Maximum Magnitude ◽  
Source Characterization ◽  
Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of the North Anatolian fault zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of the 1999 Kocaeli and Düzce earthquakes, central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that is associated with the rupture system. Uncertainty in the SSC model parameters (e.g., b value, maximum magnitude, slip rate, weights of the rupture scenarios) is considered, whereas the uncertainty in the fault geometry is not included in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

A probabilistic seismic hazard assessment for the Turkish territory—part I: the area source model

2016 ◽  
Vol 16 (8) ◽  
pp. 3367-3397 ◽  
Author(s):  
Karin Sesetyan ◽  
Mine B. Demircioglu ◽  
Tamer Y. Duman ◽  
Tolga Çan ◽  
Senem Tekin ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Source Model ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Area Source ◽  
Area Source Model

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 Probabilistic seismic hazard assessment for Bayankhongor aimag of Mongolia

2019 ◽  
pp. 43-56
Author(s):  
Ankhtsetseg D ◽  
Odonbaatar Ch ◽  
Mоngоnsuren D ◽  
Bayarsaikhan E ◽  
Dembereldulam M
Keyword(s):  
Seismic Hazard ◽  
Central Asia ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Active Regions ◽  
Source Model ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Probability Of Exceedance ◽  
Area Source

Central Asia is one of the seismically most active regions in the world. Its complex seismicity is due to the collision of the Eurasian and Indian plates, which has resulted in some of the world’s largest intra-plate events over history. The region is dominated by reverse faulting over strike slip and normal faulting events.The GSHAP project, aiming at hazard assessment on a global scale, indicates that the territory of Bayankhongor aimag, Mongolia, in Central Asia is characterized by maximum bedrock peak ground accelerations for 10% probability of exceedance in 50 years as medium as in range of 80 to 160cm/s2. In this study, which has been carried out within the framework of the project “Seismic microzoning map of center of 12 aimags, Mongolia”, the area source model and different kernel approaches are used for a probabilistic seismic hazard assessment for the Mongolia. The seismic hazard is assessed considering shallow (depth <50 km) seismicity only and employs an updated (with respect to previous projects) earthquake catalogue for the region. The hazard maps, shown in terms of 10% probability of exceedance in 50 years, are derived by using the Open Deterministic and Probabilistic Seismic Hazard Assessment (ODPSHA), which is based on the Cornell methodology. The maximum hazard observed in the region reaches 93-98 cm/s2 , which in intensity corresponds to VII in MSK64 scale in the centre of Bayankhongor aimag for 475 years mean return period.

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