Geoscience Reference
In-Depth Information
Figure 6.12 (a) HypoDD relocations of 1402 aftershocks of M
w
2.0-5.4 during 2001. Large circle
marks the location of the 2001 Bhuj mainshock. (b) Epicenters of aftershocks during 2002-4. (c) E-W
depth plot of relocated aftershocks during 2001. (d) E-W depth plot of relocated aftershocks during
2002-4. (e) N-S depth plot of relocated aftershocks during 2001. (f) N-S depth plot of relocated
aftershocks during 2002-4.
Yagi and Kikuchi (2001, eri.u-Tokyo.ac.jp) determined source duration of 20 s, and fault
dip 58
. Rupture with maximum slip of 8.5 m propagated mostly towards the west for
40 km, with a small slip towards the east for 20 km along the fault width from 8 km
below the surface to 35 km depth along the NWF. If projected onto the surface, this
would be about 60 km
°
×
30 km in area between the KMF and NWF lying between
20
E, which we take as the main rupture zone. The
have given a similar rupture model.
The epicenters of the mainshocks, foreshocks, and aftershocks during 2001 to 2009 and
depth sections are shown in
Figure 6.12
(Mandal and Pandey,
2010
;
Mandal, 2012b). The
hypocenters were first determined using the Hypo71 program with up to 56 P and S phases
with accuracy of better than 0.5 km horizontal and 1.0 km in depth (Rastogi
et al
., 2013a).
The subsurface orientation of seismogenic faults and depth of the seismogenic zone in the
20
and 23
34
N, 69
50
and 70
23
°
°
°
°
