HR: 08:40h
AN: G31D-03    [Abstracts]
TI: Creep Along the North Anatolian Fault at Ismetpasa (Western Turkey) Deduced From InSAR
AU: * Cakir, Z
EM: ziyadin.cakir@eost.u-strasbg.fr
AF: IPGP-EOST, 5, rue Ren‚ Descartes, Strasbourg, 67084 France
AU: Ergintav, S
EM: Semih.Ergintav@mam.gov.tr
AF: TUBITAK MAM, Gebze, Izmit, 41400 Turkey
AU: Akoglu, A M
EM: akoglua@itu.edu.tr
AF: ITU, Avrasya Yerbilimleri Maslak, Istanbul, 80626 Turkey
AU: Belabbes, S
EM: samir@eost.u-strasbg.fr
AF: IPGP-EOST, 5, rue Ren‚ Descartes, Strasbourg, 67084 France
AU: Meghraoui, M
EM: mustapha.Meghraoui@eost.u-strasbg.fr
AF: IPGP-EOST, 5, rue Ren‚ Descartes, Strasbourg, 67084 France
AB: Although creeping along the North Anatolian Fault (NAF) at Ismetpasa (Turkey) was discovered some thirty years ago, about a decade after the first observation of the phenomenon along the San Andreas Fault in California, little is known about its extent and rate. In order to reveal its three dimensional nature and rupture characteristics, we use Synthetic Aperture Radar Interferometry (InSAR) and dislocations on rectangular faults in elastic half space. Interferograms with temporal baselines ranging between 1.25 and 5 years show that creeping starts at the western termination of the 1943 (Mw=7.6) earthquake rupture and continues about 70-km to the west overlapping with the eastern part of the 185-km-long rupture of the 1944 (Mw=7.3) earthquake. Maximum creep rate is 10 mm/year approximately in the mid point of the creeping part of the rupture segment diminishing gradually towards the edges. Near Ismetpasa, InSAR data yield 7.7 mm/year of creep rate, consistent with those deduced from instrumental (triangulation and creepmeters) measurements (i.e. 9 mm/year). Modeling of the InSAR and GPS data suggests that the fault creep occurs most probably at a shallow depth (0-7 km). InSAR data do not support the previous claims of creep events triggered by the 1999 Izmit earthquake.
DE: 1206 Crustal movements--interplate (8155)
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting