Five shallow borehole seismic stations were installed to monitor microearthquake activities in a ... more Five shallow borehole seismic stations were installed to monitor microearthquake activities in a carbonate oil field in northern Oman since 1999. This shallow network of seismic station operated continuously until 2002 after which intermittent seismic recording took place due to lack of maintenance and failure of some stations. The objectives of the study are to determine the microseismic parameters in
Microseismicity was monitored continuously for 2003 and 2004 years using shallow downhole seismic... more Microseismicity was monitored continuously for 2003 and 2004 years using shallow downhole seismic network in a carbonate oil field in Northern Oman. A total of 406 microearthquake events were analyzed to assess events location relative to producing horizons. The depth of the microearthquakes ranges from 0 to 2.95 km below the ground surface. The events location is confined to the
A site-specific probabilistic seismic hazard assessment (PSHA) was achieved in the area of specia... more A site-specific probabilistic seismic hazard assessment (PSHA) was achieved in the area of special economic zone authority of Duqm, involving hazard evaluation at the bedrock conditions and assurance of potential site influence on seismic ground motion at the bedrock. Appropriate source and ground-motion prediction models were selected and seismic hazards were identified by means of 5% damped Uniform Hazard Spectra (UHS) for three return periods of 475, 975, and 2475 years. A logic-tree algorithm was used to study the influence of the epistemic uncertainties on the source models, earthquake recurrency and maximum magnitude, along with ground-motion prediction equations (GMPEs). The local geology effects were characterized by fundamental resonance frequency (Fo) using the horizontal-to-vertical spectral ratio technique and the soil amplification factors. The effects of soil were assessed using SHAKE91 for soil parameters defined by 55 geotechnical boreholes in conjunction with survey...
Abstract The Arabian Plate is surrounded by regions of relatively high seismicity. Accounting for... more Abstract The Arabian Plate is surrounded by regions of relatively high seismicity. Accounting for this seismicity is of great importance for seismic hazard and risk assessments, seismic zoning, and land use. In this study, a homogenous earthquake catalogue of moment-magnitude (Mw) for the Arabian Plate is provided. The comprehensive and homogenous earthquake catalogue provided in the current study spatially involves the entire Arabian Peninsula and neighboring areas, covering all earthquake sources that can generate substantial hazard for the Arabian Plate mainland. The catalogue extends in time from 19 to 2015 with a total number of 13,156 events, of which 497 are historical events. Four polygons covering the entire Arabian Plate were delineated and different data sources including special studies, local, regional and international catalogues were used to prepare the earthquake catalogue. Moment magnitudes (Mw) that provided by original sources were given the highest magnitude type priority and introduced to the catalogues with their references. Earthquakes with magnitude differ from Mw were converted into this scale applying empirical relationships derived in the current or in previous studies. The four polygons catalogues were included in two comprehensive earthquake catalogues constituting the historical and instrumental periods. Duplicate events were identified and discarded from the current catalogue. The present earthquake catalogue was declustered in order to contain only independent events and investigated for the completeness with time of different magnitude spans.
We present a report from the work of the International Tsunami Survey Team in Oman in the afterma... more We present a report from the work of the International Tsunami Survey Team in Oman in the aftermath of the 2004 Sumatra tsunami. During an 7-day campaign, the team surveyed approximately 750 km of coastlines along the southern shore of the country, building a database of 41 standardized measurements of flow-depth, run-up and inundation, obtained primarily from eyewitness reports. Maximum
In August 2005, a team surveyed the effects of the December 2004 Indian Ocean tsunami on the sout... more In August 2005, a team surveyed the effects of the December 2004 Indian Ocean tsunami on the southern coast of Oman. Runup and inundation were obtained at 41 sites, extending over a total of 750 km of shoreline. Measured runup ranged from 3.25 m in the vicinity of Salalah to a negligible value at one location on Masirah Island. In general, the largest values were found in the western part of the surveyed area. Significant incidents were documented in the port of Salalah, where a 285-m-long vessel broke its moorings and drifted inside and outside the port, and another ship struck the breakwater while attempting to enter the harbor. The general hazard to Oman from tsunamis may be greatest from the neighboring Makran subduction zone in western Pakistan.
Five shallow borehole seismic stations were installed to monitor microearthquake activities in a ... more Five shallow borehole seismic stations were installed to monitor microearthquake activities in a carbonate oil field in northern Oman since 1999. This shallow network of seismic station operated continuously until 2002 after which intermittent seismic recording took place due to lack of maintenance and failure of some stations. The objectives of the study are to determine the microseismic parameters in
Microseismicity was monitored continuously for 2003 and 2004 years using shallow downhole seismic... more Microseismicity was monitored continuously for 2003 and 2004 years using shallow downhole seismic network in a carbonate oil field in Northern Oman. A total of 406 microearthquake events were analyzed to assess events location relative to producing horizons. The depth of the microearthquakes ranges from 0 to 2.95 km below the ground surface. The events location is confined to the
A site-specific probabilistic seismic hazard assessment (PSHA) was achieved in the area of specia... more A site-specific probabilistic seismic hazard assessment (PSHA) was achieved in the area of special economic zone authority of Duqm, involving hazard evaluation at the bedrock conditions and assurance of potential site influence on seismic ground motion at the bedrock. Appropriate source and ground-motion prediction models were selected and seismic hazards were identified by means of 5% damped Uniform Hazard Spectra (UHS) for three return periods of 475, 975, and 2475 years. A logic-tree algorithm was used to study the influence of the epistemic uncertainties on the source models, earthquake recurrency and maximum magnitude, along with ground-motion prediction equations (GMPEs). The local geology effects were characterized by fundamental resonance frequency (Fo) using the horizontal-to-vertical spectral ratio technique and the soil amplification factors. The effects of soil were assessed using SHAKE91 for soil parameters defined by 55 geotechnical boreholes in conjunction with survey...
Abstract The Arabian Plate is surrounded by regions of relatively high seismicity. Accounting for... more Abstract The Arabian Plate is surrounded by regions of relatively high seismicity. Accounting for this seismicity is of great importance for seismic hazard and risk assessments, seismic zoning, and land use. In this study, a homogenous earthquake catalogue of moment-magnitude (Mw) for the Arabian Plate is provided. The comprehensive and homogenous earthquake catalogue provided in the current study spatially involves the entire Arabian Peninsula and neighboring areas, covering all earthquake sources that can generate substantial hazard for the Arabian Plate mainland. The catalogue extends in time from 19 to 2015 with a total number of 13,156 events, of which 497 are historical events. Four polygons covering the entire Arabian Plate were delineated and different data sources including special studies, local, regional and international catalogues were used to prepare the earthquake catalogue. Moment magnitudes (Mw) that provided by original sources were given the highest magnitude type priority and introduced to the catalogues with their references. Earthquakes with magnitude differ from Mw were converted into this scale applying empirical relationships derived in the current or in previous studies. The four polygons catalogues were included in two comprehensive earthquake catalogues constituting the historical and instrumental periods. Duplicate events were identified and discarded from the current catalogue. The present earthquake catalogue was declustered in order to contain only independent events and investigated for the completeness with time of different magnitude spans.
We present a report from the work of the International Tsunami Survey Team in Oman in the afterma... more We present a report from the work of the International Tsunami Survey Team in Oman in the aftermath of the 2004 Sumatra tsunami. During an 7-day campaign, the team surveyed approximately 750 km of coastlines along the southern shore of the country, building a database of 41 standardized measurements of flow-depth, run-up and inundation, obtained primarily from eyewitness reports. Maximum
In August 2005, a team surveyed the effects of the December 2004 Indian Ocean tsunami on the sout... more In August 2005, a team surveyed the effects of the December 2004 Indian Ocean tsunami on the southern coast of Oman. Runup and inundation were obtained at 41 sites, extending over a total of 750 km of shoreline. Measured runup ranged from 3.25 m in the vicinity of Salalah to a negligible value at one location on Masirah Island. In general, the largest values were found in the western part of the surveyed area. Significant incidents were documented in the port of Salalah, where a 285-m-long vessel broke its moorings and drifted inside and outside the port, and another ship struck the breakwater while attempting to enter the harbor. The general hazard to Oman from tsunamis may be greatest from the neighboring Makran subduction zone in western Pakistan.
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Papers by Y. al-Shijbi