scholarly journals Review of Seismic Characteristics in Erbil City, the Capital of the Kurdistan Region of Iraq

2019 ◽  
Vol 9 (2) ◽  
pp. 161-170
Author(s):  
Zina A. AbdulJaleel ◽  
Bahman O. Taha

Erbil city essentially suffers from the risk of earthquakes generated by Zagros-Taurus Belt. The central objective of this study is to identify the seismic characteristics and required seismic parameters for structural analysis. The methodology concentrated on reviewing the seismology and geology of Erbil city. It was concluded that the tectonically classified by an outer platform of the low folded zone in the position of Western Zagros Fold-Thrust Belt of the Arabian plate, geologically covered by Quaternary sediments and lithologically described by fluvial sediments, and the dynamic soil properties classified by site Class D. Seismicity review indicated that the seismic source is characterized by strike-slip (normal) fault and majority events exhibit at the shallow crustal with expected moment magnitude between 6 and 7.5. It was observed that the peak ground acceleration (PGA) has been updated, especially after the last cyclic earthquake in the region. The summary of the previous seismic hazard indicates that the PGA according to the World Health Organization, Global Seismic Hazard Assessment Program, and Uniform building code is identified by the value higher than 0.3 g for 475 years return period, while according to national probabilistic seismic hazard analysis studies in Iraq and Arabian Peninsula is identified by 0.4 g for 2% probability of exceedance in 50 years (2475 years return period), and estimated PGA to be 0.25 g for 10% likelihood of exceedance in 50 years (475 years return period), in a term of 5% damped at bedrock condition. Proposed spectral acceleration (Sa) in Erbil city at 0.2 and 1.0 s evaluated to be 1.0 g and 0.53 g, for the site Class D and compared with Sa in the literature.

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenming Wang ◽  
David T. Butler ◽  
Edward W. Woolery ◽  
Lanmin Wang

A scenario seismic hazard analysis was performed for the city of Tianshui. The scenario hazard analysis utilized the best available geologic and seismological information as well as composite source model (i.e., ground motion simulation) to derive ground motion hazards in terms of acceleration time histories, peak values (e.g., peak ground acceleration and peak ground velocity), and response spectra. This study confirms that Tianshui is facing significant seismic hazard, and certain mitigation measures, such as better seismic design for buildings and other structures, should be developed and implemented. This study shows that PGA of 0.3 g (equivalent to Chinese intensity VIII) should be considered for seismic design of general building and PGA of 0.4 g (equivalent to Chinese intensity IX) for seismic design of critical facility in Tianshui.


1999 ◽  
Vol 42 (6) ◽  
Author(s):  
V. I. Ulomov ◽  
. The GSHAP Region Working Group

The GSHAP Regional Centre in Moscow, UIPE, has coordinated the seismic hazard mapping for the whole territory of the former U.S.S.R. and border regions. A five-year program was conducted to assemble for the whole area, subdivided in five overlapping blocks, the unified seismic catalogue with uniform magnitude, the strong motion databank and the seismic zones model (lineament-domain-source), which form the basis of a newly developed deterministic-probabilistic computation of seismic hazard assessment. The work was conducted in close cooperation with border regions and GSHAP regional centers. The hazard was originally computed in terms of expected MSK intensity and then transformed into expected peak ground acceleration with 10% exceedance probability in 50 years.


1999 ◽  
Vol 42 (6) ◽  
Author(s):  
B. Tavakoli ◽  
M. Ghafory-Ashtiany

The development of the new seismic hazard map of Iran is based on probabilistic seismic hazard computation using the historical earthquakes data, geology, tectonics, fault activity and seismic source models in Iran. These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using current probabilistic procedures. They display the probabilistic estimates of Peak Ground Acceleration (PGA) for the return periods of 75 and 475 years. The maps have been divided into intervals of 0.25 degrees in both latitudinal and longitudinal directions to calculate the peak ground acceleration values at each grid point and draw the seismic hazard curves. The results presented in this study will provide the basis for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, and the preliminary site evaluation of critical facilities.


Geosciences ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 489 ◽  
Author(s):  
Şeşetyan ◽  
Tümsa ◽  
Akinci

The increase in the wealth of information on the seismotectonic structure of the Marmara region after two devastating earthquakes (M7.6 Izmit and M7.2 Duzce events) in the year 1999 opened the way for the reassessment of the probabilistic seismic hazard in the light of new datasets. In this connection, the most recent findings and outputs of different national and international projects concerning seismicity and fault characterization in terms of geometric and kinematic properties are exploited in the present study to build an updated seismic hazard model. A revised fault segmentation model, alternative earthquake rupture models under a Poisson and renewal assumptions, as well as recently derived global and regional ground motion prediction equations (GMPEs) are put together in the present model to assess the seismic hazard in the region. Probabilistic seismic hazard assessment (PSHA) is conducted based on characteristic earthquake modelling for the fault segments capable of producing large earthquakes and smoothed seismicity modelling for the background smaller magnitude earthquake activity. The time-independent and time-dependent seismic hazard results in terms of spatial distributions of three ground-shaking intensity measures (peak ground acceleration, PGA, and 0.2 s and 1.0 s spectral accelerations (SA) on rock having 10% and 2% probabilities of exceedance in 50 years) as well as the corresponding hazard curves for selected cities are shown and compared with previous studies.


Author(s):  
Girish Chandra Joshi ◽  
Mukat Lal Sharma

In the present study the authors evaluate uncertainties in the seismic hazard assessment for the Northern Indian region, based on the probabilistic seismic hazard analysis (PSHA). The newly compiled earthquake data has been treated for the quality, consistency, and homogeneity in a systematic manner to find out the uncertainties in every step of calculations. Based on the geological and tectonic setup, seismicity and other geophysical anomalies, a seismotectonic model of the region has been developed. The seismic hazard parameters are calculated based on giving proper weight to specific region. The peak ground acceleration (PGA) is estimated for various return periods for the Northern Indian region using a logic tree approach. The variation at the input level in terms of the source models and different Ground Motion Prediction Equations (GMPEs) is used. To examine into the effect of source modelling and GMPEs, the Coefficient of Variation (COV) maps have been generated. To encompass the region and for better resolution, the peak ground acceleration (PGA) is estimated at 15 minute intervals. The COV values due to all branch points in the logic tree decrease with distance from the source and conspicuous increase toward fault boundaries are observed.


2018 ◽  
Vol 195 ◽  
pp. 03019
Author(s):  
Rian Mahendra Taruna ◽  
Vrieslend Haris Banyunegoro ◽  
Gatut Daniarsyad

The Lombok region especially Mataram city, is situated in a very active seismic zone because of the existence of subduction zones and the Flores back arc thrust. Hence, the peak ground acceleration (PGA) at the surface is necessary for seismic design regulation referring to SNI 1726:2012. In this research we conduct a probabilistic seismic hazard analysis to estimate the PGA at the bedrock with a 2% probability of exceedance in 50 years corresponding to the return period of 2500 years. These results are then multiplied by the amplification factor referred from shear wave velocity at 30 m depth (Vs30) and the microtremor method. The result of the analysis may describe the seismic hazard in Mataram city which is important for building codes.


2009 ◽  
Vol 9 (3) ◽  
pp. 865-878 ◽  
Author(s):  
K. S. Vipin ◽  
P. Anbazhagan ◽  
T. G. Sitharam

Abstract. In this work an attempt has been made to evaluate the seismic hazard of South India (8.0° N–20° N; 72° E–88° E) based on the probabilistic seismic hazard analysis (PSHA). The earthquake data obtained from different sources were declustered to remove the dependent events. A total of 598 earthquakes of moment magnitude 4 and above were obtained from the study area after declustering, and were considered for further hazard analysis. The seismotectonic map of the study area was prepared by considering the faults, lineaments and the shear zones in the study area which are associated with earthquakes of magnitude 4 and above. For assessing the seismic hazard, the study area was divided into small grids of size 0.1°×0.1°, and the hazard parameters were calculated at the centre of each of these grid cells by considering all the seismic sources with in a radius of 300 km. Rock level peak horizontal acceleration (PHA) and spectral acceleration (SA) values at 1 s corresponding to 10% and 2% probability of exceedance in 50 years have been calculated for all the grid points. The contour maps showing the spatial variation of these values are presented here. Uniform hazard response spectrum (UHRS) at rock level for 5% damping and 10% and 2% probability of exceedance in 50 years were also developed for all the grid points. The peak ground acceleration (PGA) at surface level was calculated for the entire South India for four different site classes. These values can be used to find the PGA values at any site in South India based on site class at that location. Thus, this method can be viewed as a simplified method to evaluate the PGA values at any site in the study area.


2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Phan Trinh ◽  
Hoang Vinh ◽  
Nguyen Huong ◽  
Ngo Liem

AbstractBased on remote sensing, geological data, geomorphologic analysis, and field observations, we determine the fault system which is a potential source of earthquakes in Hoa-Binh reservoir. It is the sub-meridian fault system composed of fault segments located in the central part of the eastern and western flanks of the Quaternary Hoa-Binh Graben: the Hoa-Binh 1 fault is east-dipping (75–80°), N-S trending, 4 km long, situated in the west of the Hoa-Binh Graben, and the Hoa-Binh 2 is a west-dipping (75–80°), N-S trending; 8.4 km long fault, situated in the east of the Hoa-Binh Graben. The slip rate of normal fault in Hoa-Binh hydropower dam was estimated at 0.3–1.1 mm/yr. The Maximum Credible Earthquake (MCE) and Peak Ground Acceleration (PGA) in the Hoa-Binh hydropower dam have been assessed. The estimated MCE of HB.1 and HB.2 is 5.6 and 6.1 respectively, and the maximum PGA at Hoa-Binh dam is 0.30 g and 0.40 g, respectively. The assessment of seismic hazard in Hoa-Binh reservoir is a typical example of seismic hazards of a large dam constructed in an area of low seismicity and lack of law of seismic attenuation.


Author(s):  
D. Al-Dogom ◽  
K. Schuckma ◽  
R. Al-Ruzouq

<p><strong>Abstract.</strong> Assessing and analyzing the spatial distribution of earthquake events aids in identifying the presence of clustering and reveals hot and cold spots across the study area. Combining the spatial analysis of earthquake events with other geographical and geophysical parameters leads to more understanding of the vulnerability of critical infrastructure and the demographics of the affected population. This study will use Geographical Information Systems (GIS) to examine the spatiotemporal occurrence of earthquake events throughout the Arabian plate and their effect on the United Arab Emirates (UAE). Spatial pattern analysis techniques, including Moran I and Getis–Ord Gi*, were applied to 115 years of earthquakes (1900&amp;ndash;2015) that have occurred throughout the Arabian plate. The directional distribution (standard deviational ellipse) of earthquake magnitudes was analyzed to determine the spatial characteristics and the directional tendency of the earthquakes throughout the Arabian plate. Afterword, geophysical parameters of UAE, specifically Peak Ground Acceleration (PGA), fault line distance, slope, soil type, and geology were ranked, weighted based on its contribution and combined using an Analytic Hierarchy Process (AHP) to identify and locate seismic hazard zones. The resulted Seismic Hazard Zonation Map (SHZM) was classified to five hazard zones ranging from very high to very low. It has been found that Fujairah city sited in the “very High” zone, Sharjah and Dubai cities located from “High” to moderate zones while Abu Dhabi city stands relatively far from seismic hot spots and major faults and placed in the low seismic hazard zone. The results of this study could help improve urban planning and emergency mitigation strategies in UAE.</p>


2020 ◽  
Vol 9 (2) ◽  
pp. 116
Author(s):  
Rohima Wahyu Ningrum ◽  
Wiwit Suryanto ◽  
Hendra Fauzi ◽  
Estuning Tyas Wulan Mei

The earthquake that occurred in the West Halmahera region was very detrimental, even though the human casualties were not very significant. But it will affect the stability and capacity of a region in terms of regional development. The mapping of earthquake-prone areas is carried out by a probabilistic seismic hazard analysis (PSHA) method to analyze soil movement parameters, namely Peak Ground Acceleration so that it can determine earthquake-prone areas in West Halmahera. The results of seismic hazard analysis show that the West Halmahera area is an area that is relatively prone to earthquake hazards because it is still strongly influenced by subduction (megathrust) earthquakes from the Philippine plate, Maluku sea and Sangihe. This is indicated by the value of earthquake acceleration on the Peak Ground Acceleration for the 500 year return period of around 0.38 - 3.69 g and 0.30 - 3.69 g for the 2500 year return period.


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