Publication Date:
2017-04-04
Description:
The aim of this work is to infer the slip distribution and rupture velocity
along the rupture zone of the 26 December 2004 Sumatra–Andaman earthquake from
available tide gage records of the tsunami. We selected waveforms from 14 stations,
distributed along the coast of the Indian Ocean. Then we subdivided the fault plane
into 16 subfaults (both along strike and downdip) following the geometry and mechanism
proposed by Banerjee et al. (2005) and computed the corresponding Green’s
functions by numerical solution of the shallow-water equations through a finitedifference
method. The slip distribution and rupture velocity were determined simultaneously
by means of a simulated annealing technique. We compared the recorded
and synthetic waveforms in the time domain, using a cost function that is a trade-off
between the L1 and L2 norms. Preliminary tests on a synthetic dataset, together with
a posteriori statistical analysis of the model ensemble enabled us to assess the effectiveness
of the method and to quantify the model uncertainty. The main finding
is that the best source model features a nonuniform distribution of coseismic slip,
with high slip values concentrated into three main patches: the first is located in the
southern part of the fault, off the coast of the Aceh Province; the second between
6.5 N and 11 N; and the third at depth, between 11 N and 14 N. Furthermore, we
estimated that the rupture propagated at an average speed of 2.0 km/sec.
Description:
Published
Description:
S223-S231
Description:
3.1. Fisica dei terremoti
Description:
JCR Journal
Description:
partially_open
Keywords:
Sumatra
;
earthquake
;
inversion
;
tsunami
;
04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
