HR: 14:20h
AN: U53A-03 INVITED    [Abstracts]
TI: Lessons from 2007 Mentawai Islands Earthquake
AU: * McCloskey, J
EM: j.mccloskey@ulster.ac.uk
AF: Geophysics Research Group, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Ireland
AU: Antonioli, A
EM: antonioli@ingv.it
AF: Department of Seismology and Tectonophysics, INGV, Via di Vigna Murata 605, Rome, 00143, Italy
AU: Piatenesi, A
EM: piatenesi@ingv.it
AF: Department of Seismology and Tectonophysics, INGV, Via di Vigna Murata 605, Rome, 00143, Italy
AU: Steacy, S
EM: s.steacy@ulster.ac.uk
AF: Geophysics Research Group, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Ireland
AU: Nalbant, S
EM: ss.nalbant@ulster.ac.uk
AF: Geophysics Research Group, University of Ulster, Cromore Road, Coleraine, BT52 1SA, Ireland
AU: Cocco, M
EM: cocco@ingv.it
AF: Department of Seismology and Tectonophysics, INGV, Via di Vigna Murata 605, Rome, 00143, Italy
AB: The 12/09/07 Mentawai Islands, M8.4 earthquake may, by its waywardness, contribute greatly both to our understanding of the occurrence of great subduction zone events and to their tsunamigenic potential. The earthquake nucleated off-shore Bengkulu in a region which likely experienced up to 18m of slip in the 1833 earthquake; at current rates of convergence only some 10m of this slip has been replaced and assessments of plate coupling in the epicentral region would suggest some of this has been relaxed aseismically. The megathrust north of Enggano Island has been remarkably quite during the instrumental period. Studies based on accelerating moment release have assigned low probabilities of occurrence for a great earthquake on this segment. Other studies employing interaction stresses as well as paleogeodesy and contemporary convergence estimates indicated that the most likely hypocenter for a Mentawai event was under Siberut Island; the hypocenter of the September event experienced no interaction stress from the 2004 or 2005 earthquakes. Preliminary slip inversions indicate that the maximum slip on the event was just 4 meters and, while the aftershock distribution would suggest that the rupture occupied much of the 1833 patch, it appears that much of the area experienced such small slip that the possibility of re-rupture in a future great earthquake cannot be discounted. Such a possibility has the potential to advance our understanding of the recurrence behaviour of subduction zone earthquakes. Finally, the earthquake generated a tsunami whose height and geographic distribution might contribute to our understanding of the relationship between earthquake slip and tsunami energy.
DE: 4564 Tsunamis and storm surges
DE: 7209 Earthquake dynamics (1242)
DE: 7223 Earthquake interaction, forecasting, and prediction (1217, 1242)
SC: Union [U]
MN: 2007 Fall Meeting