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Source parameters of the Bhuj earthquake, India of January 26, 2001 from height and gravity changes
Author(s) -
Chandrasekhar D. V.,
Mishra D. C.,
Singh B.,
Vijayakumar V.,
Bürgmann Roland
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl020768
Subject(s) - geology , aftershock , seismology , slip (aerodynamics) , geodesy , physics , thermodynamics
Height and gravity measurements observed along a profile across the epicentral area before and after the January 26, 2001, M w 7.6 Bhuj earthquake show a maximum uplift of 1.57 ± 0.5 m and a corresponding gravity change of −393 ± 18 μGal. A best‐fit, single‐dislocation model inverted from the height‐changes using non‐linear optimization methods indicates that the high‐slip rupture was well contained in the aftershock zone and likely did not break to depths shallower than ∼10 km. Source parameters arrived in the present study agree well with those provided by seismic inversions and the distribution of aftershocks. Gravity data over the epicentral area are well modeled by the preferred model; however, a strong influence of shallow hydrological processes is inferred for three sites, two located on the Banni plains, whose mean gravity change ∼280 μGal suggests a total mass redistribution of as much as 2.9 Mt.