A Seismogenic Zone Model for Seismic Hazard Studies in Northwestern Africa

2018 ◽  
pp. 643-680 ◽  
Author(s):  
J. A. Peláez ◽  
J. Henares ◽  
M. Hamdache ◽  
C. Sanz de Galdeano
Keyword(s):  
Seismic Hazard ◽  
Seismogenic Zone ◽  
Zone Model ◽  
Northwestern Africa

Effects of temporal variations in seismicity on seismic hazard

1981 ◽  
Vol 71 (1) ◽  
pp. 321-334
Author(s):  
Robin K. McGuire ◽  
Theodore P. Barnhard
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Seismic Activity ◽  
Time Window ◽  
Hazard Analysis ◽  
The United States ◽  
Temporal Variations ◽  
Seismogenic Zone ◽  
Eastern United States ◽  
Ground Shaking

abstract The accuracy of stationary mathematical models of seismicity for calculating probabilities of damaging shaking is examined using the history of earthquakes in China from 1350 A.D. to 1949 A.D. During this time, rates of seismic activity varied periodically by a factor of 10. Probabilities of damaging shaking are calculated in 62 cities in North China using 50 yr of earthquake data to estimate seismicity parameters; the probabilities are compared to statistics of damaging shaking in the same cities for 50 yr following the data window. These comparisons indicate that the seismic hazard analysis is accurate if: (1) the maximum possible earthquake size in each seismogenic zone is determined from the entire seismic history rather than from a short-time window; and (2) the future seismic activity can be estimated accurately. The first condition emphasizes the importance of realistically estimating the maximum possible size of earthquakes on faults. The second indicates the need to understand possible trends in seismic activity where these exist, or to develop an earthquake prediction capability with which to estimate future activity. Without the capability of estimating future seismicity, stationary models provide less accurate but generally conservative indications of seismic ground-shaking hazard. In the United States, the available earthquake history is brief but gives no indication of changing rates of activity. The rate of seismic strain release in the Central and Eastern United States has been constant over the last 180 yr, and the geological record of earthquakes on the southern San Andreas Fault indicates no temporal trend for large shocks over the last 15 centuries. Both observations imply that seismic activity is either stationary or of such a long period that it may be treated as stationary for seismic hazard analyses in the United States.

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 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.

Genesis of continental seismogenic zone and a new fault zone model

2000 ◽  
Vol 45 (20) ◽  
pp. 1886-1892
Author(s):  
Junlai Liu ◽  
M. Shimada
Keyword(s):  
Fault Zone ◽  
Seismogenic Zone ◽  
Zone Model

scholarly journals Preliminary seismic hazard assessment of the Arctic Gakkel ridge and surrounding

2019 ◽  
Vol 1 (1) ◽  
pp. 35-45
Author(s):  
Bela Assinovskaya ◽  
Natal’ia Panas ◽  
Galina Antonovskaya
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Industrial Development ◽  
Seismic Hazard Assessment ◽  
The Arctic ◽  
Primary Data ◽  
Seismogenic Zone ◽  
Earthquake Catalog ◽  
Gakkel Ridge ◽  
Study Region

This study describes primary data, methods of estimation and final results of the preliminary seismic hazard assessment in the region of the Gakkel Ridge that is a northernmost seismogenic zone of the Earth. According to geological data, the region is considered potentially oil and gas, but its industrial development has not yet begun. These authors for the Baltic Sea did the similar work earlier. At the first stage of this study, the earthquake catalog unified in magnitude Mw was compiled for the period from 1912 to 2014. Information on seismic events from historical sources and the ISC catalog was used, as well as the results of observations of the Arkhangelsk seismic network in the Arctic for 2014–2018. The representative part of earthquake data was revealed and the seismic regime has been studied. By seismicity origin, the region is divided into the highly active rift zone of the Gakkel Ridge and the continental slopes of the Barents, Kara and eastern Laptev seas with weaker activity, separated and framed by aseismic areas like the Nansen, Amundsen basins and the Lomonosov Ridge. The seismic zoning of the study region was carried out based on structural analysis of geological and geophysical data. The mapping of probabilistic seismic hazard in terms of maximum accelerations of PGA soil movements for a return period of 500 and 100 years (10% probability of exceedance in the next 50 and 10 years) was conducted using the CRISIS program. As expected, the most dangerous was the Gakkel zone about 200 km wide.

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.

DETERMINISTIC SEISMIC HAZARD ANALYSIS OF ANDAMAN AND NICOBAR ISLANDS

2013 ◽  
Vol 07 (04) ◽  
pp. 1350035
Author(s):  
N. P. KATARIA ◽  
M. SHRIKHANDE ◽  
J. D. DAS
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Tectonic Setting ◽  
Seismic Hazard Assessment ◽  
Active Regions ◽  
Seismogenic Zone ◽  
Ground Acceleration ◽  
Design Spectrum ◽  
Seismogenic Source ◽  
Deterministic Seismic Hazard

An important component of hazard mitigation is to estimate the future hazard for design calculations. In the present study, a deterministic seismic hazard assessment of Andaman and Nicobar region is carried out, which is one of the most seismically active regions of India. The study area is divided into seven seismogenic source zones based on seismicity and tectonic setting. For ground motion estimation at Andaman and Nicobar, for each seismogenic zone different attenuation relationship is used as per tectonic setting of that seismogenic zone. In order to generate the site specific design spectrum, final results are calculated in the form of peak ground acceleration (PGA) and 5%-damped pseudo-spectral acceleration (PSA) for 0.2 s and 1 s. Calculated results are compared with some earlier works for the studied area and the probable reasons for variations are discussed.

scholarly journals Estimation of Recurrence Interval of Large Earthquakes on the Central Longmen Shan Fault Zone Based on Seismic Moment Accumulation/Release Model

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Junjie Ren ◽  
Shimin Zhang
Keyword(s):  
Seismic Hazard ◽  
Fault Zone ◽  
Seismic Moment ◽  
Large Earthquake ◽  
Recurrence Interval ◽  
Seismogenic Zone ◽  
2008 Wenchuan Earthquake ◽  
Longmen Shan Fault ◽  
Release Model ◽  
Large Earthquakes

Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing seismic hazard. The 2008 Wenchuan earthquake (Mw 7.9) occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF) and the Guanxian-Jiangyou fault (GJF). However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-seismic trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data and construct a characteristic seismic moment accumulation/release model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7 ± 0.3) × 1017 N m/yr, and a recurrence interval of 3900 ± 400 yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for seismic hazard analysis in the Longmen Shan region.

A seismic source zone model for the seismic hazard assessment of the Italian territory

2008 ◽  
Vol 450 (1-4) ◽  
pp. 85-108 ◽  
Author(s):  
Carlo Meletti ◽  
Fabrizio Galadini ◽  
Gianluca Valensise ◽  
Massimiliano Stucchi ◽  
Roberto Basili ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Source Zone ◽  
Zone Model ◽  
Italian Territory
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