HR: 14:55h
AN: S53C-06 [Abstracts]
TI: Inversion of Geodetic Data Monitoring the 2002 Silent Earthquake in the Guerrero Seismic gap: Resolution and non Uniqueness Analysis
AU: Tary, J
EM: jbtary@obs.ujf-grenoble.fr
AF: LGIT - Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: * Cotton, F
EM: fabrice.cotton@obs.ujf-grenoble.fr
AF: LGIT - Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: Campillo, M
EM: michel.campillo@obs.ujf-grenoble.fr
AF: LGIT - Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: Cotte, N
EM: nathalie.cotte@obs.ujf-grenoble.fr
AF: LGIT - Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: Walpersdorf, A
EM: andrea.walpersdorf@obs.ujf-grenoble.fr
AF: LGIT - Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AU: Vergnolle, M
EM: mathilde.vergnolle@obs.ujf-grenoble.fr
AF: LGIT - Universite Joseph Fourier, BP 53, Grenoble cedex 9, 38041, France
AB:
The 2002 Guerrero silent event began in october 2001 and lasted for 6-7 months. The equivalent Mw of the event
was 7.5. Permanent GPS stations have monitored this event. The analysis of the full data set using
MIT's GAMIT 10.3 software gives clear evidence for the slow slip event by eliminating all
major non tectonical signals. Horizontal displacements up to 6 cm over an area of ~500 * 250 km2 have
been recorded. Both horizontal and vertical displacements were inverted simultaneously to map the slip
distribution on the plate interface during this slow-slip event. Our results show that the slip occurred both in the
locked (seismogenic) and the partially coupled transition zones. A time window inversions scheme has been
developed to illustrate the slip kinematics. During the first 6 months, the slip propagated from the central part
toward the edges. At the end of the event the slip propagated in the opposite direction (from the edges toward the
central part). Our results also indicate significant time dependent rake changes. Resolution and non uniqueness
analysis have been performed to illustrate the effects of stations locations and inversion smoothing choices.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Seismology [S]
MN: 2007 Fall Meeting