Fault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmara

Handle URI:
http://hdl.handle.net/10754/555754
Title:
Fault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmara
Authors:
Oglesby, David D.; Mai, Paul Martin ( 0000-0002-9744-4964 )
Abstract:
Using the 3-D finite-element method, we develop dynamic spontaneous rupture models of earthquakes on the North Anatolian Fault system in the Sea of Marmara, Turkey, considering the geometrical complexity of the fault system in this region. We find that the earthquake size, rupture propagation pattern and ground motion all strongly depend on the interplay between the initial (static) regional pre-stress field and the dynamic stress field radiated by the propagating rupture. By testing several nucleation locations, we observe that those far from an oblique normal fault stepover segment (near Istanbul) lead to large through-going rupture on the entire fault system, whereas nucleation locations closer to the stepover segment tend to produce ruptures that die out in the stepover. However, this pattern can change drastically with only a 10° rotation of the regional stress field. Our simulations also reveal that while dynamic unclamping near fault bends can produce a new mode of supershear rupture propagation, this unclamping has a much smaller effect on the speed of the peak in slip velocity along the fault. Finally, we find that the complex fault geometry leads to a very complex and asymmetric pattern of near-fault ground motion, including greatly amplified ground motion on the insides of fault bends. The ground-motion pattern can change significantly with different hypocentres, even beyond the typical effects of directivity. The results of this study may have implications for seismic hazard in this region, for the dynamics and ground motion of geometrically complex faults, and for the interpretation of kinematic inverse rupture models.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
Fault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmara 2012, 188 (3):1071 Geophysical Journal International
Publisher:
Oxford University Press (OUP)
Journal:
Geophysical Journal International
Issue Date:
Mar-2012
DOI:
10.1111/j.1365-246X.2011.05289.x
Type:
Article
ISSN:
0956540X
Additional Links:
http://gji.oxfordjournals.org/cgi/doi/10.1111/j.1365-246X.2011.05289.x
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorOglesby, David D.en
dc.contributor.authorMai, Paul Martinen
dc.date.accessioned2015-05-26T07:14:55Zen
dc.date.available2015-05-26T07:14:55Zen
dc.date.issued2012-03en
dc.identifier.citationFault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmara 2012, 188 (3):1071 Geophysical Journal Internationalen
dc.identifier.issn0956540Xen
dc.identifier.doi10.1111/j.1365-246X.2011.05289.xen
dc.identifier.urihttp://hdl.handle.net/10754/555754en
dc.description.abstractUsing the 3-D finite-element method, we develop dynamic spontaneous rupture models of earthquakes on the North Anatolian Fault system in the Sea of Marmara, Turkey, considering the geometrical complexity of the fault system in this region. We find that the earthquake size, rupture propagation pattern and ground motion all strongly depend on the interplay between the initial (static) regional pre-stress field and the dynamic stress field radiated by the propagating rupture. By testing several nucleation locations, we observe that those far from an oblique normal fault stepover segment (near Istanbul) lead to large through-going rupture on the entire fault system, whereas nucleation locations closer to the stepover segment tend to produce ruptures that die out in the stepover. However, this pattern can change drastically with only a 10° rotation of the regional stress field. Our simulations also reveal that while dynamic unclamping near fault bends can produce a new mode of supershear rupture propagation, this unclamping has a much smaller effect on the speed of the peak in slip velocity along the fault. Finally, we find that the complex fault geometry leads to a very complex and asymmetric pattern of near-fault ground motion, including greatly amplified ground motion on the insides of fault bends. The ground-motion pattern can change significantly with different hypocentres, even beyond the typical effects of directivity. The results of this study may have implications for seismic hazard in this region, for the dynamics and ground motion of geometrically complex faults, and for the interpretation of kinematic inverse rupture models.en
dc.publisherOxford University Press (OUP)en
dc.relation.urlhttp://gji.oxfordjournals.org/cgi/doi/10.1111/j.1365-246X.2011.05289.xen
dc.rightsArchived with thanks to Geophysical Journal International © The Authors Geophysical Journal International © 2012 RASen
dc.subjectEarthquake dynamicsen
dc.subjectEarthquake ground motionsen
dc.subjectEarthquake interaction, forecasting, and predictionen
dc.subjectComputational seismologyen
dc.subjectContinental margins: transformen
dc.subjectDynamics and mechanics of faultingen
dc.titleFault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmaraen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalGeophysical Journal Internationalen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Earth Sciences, University of California, Riverside, CA 92521, USA.en
kaust.authorMai, Paul Martinen
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