Kinematics of the Great 2004 Sumatra-Andaman Earthquake from ...

brontidegrrrMechanics

Nov 14, 2013 (3 years and 10 months ago)

65 views

Kinematics of the Great 2004 Sumatra
-
Andaman Earthquake from GPS static offsets


Paramesh Banerjee


Abstract:

The Great 26 December 2004 Tsunami
-
producing Sumatra
-
Andaman earthquake caused
a large area of earth’s surface to shrink leading to change in shap
e and size of the earth.
This instantaneous coseismic visco
-
elastic response of the upper lithosphere to tectonic
plate adjustment process, were picked up by a large number of Continuously operating
GPS stations at distances of upto 4500km from the epicent
er. Using GPS measured
coseismic static offsets, we estimated energy release of the mega
-
earthquake equivalent
to a magnitude of Mw 9.2, and led up to detailed modelling of the kinematics of the
rupture process. Further analysis of the post
-
seismic GPS dat
a indicated

in favour of a
vigorous viscoelastic relaxation involving both upper and lower mantle. Following the
2004 event, it was possible to predict that the Coulomb Failure Stress increased by about
0.25 bar in the region of future hypocentral zone of
March 2005 Nias earthquake.