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Coseismic velocity change associated with the 2011 Van earthquake ( M 7.1): Crustal response to a major event
Author(s) -
Acarel Diğdem,
Bulut Fatih,
Bohnhoff Marco,
Kartal Recai
Publication year - 2014
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 - 10.1002/2014gl060624
Subject(s) - hypocenter , geology , seismology , crust , aftershock , subduction , geodesy , ambient noise level , slip (aerodynamics) , induced seismicity , geophysics , tectonics , geomorphology , sound (geography) , physics , thermodynamics
Monitoring coseismic velocity changes is a major challenge, since the Earth crust has to be uniformly sampled at preseismic, coseismic, and postseismic stages using repeating active or natural sources. Here we investigate the crustal response to the 2011 Van/Turkey earthquake using ambient noise, which provides the best possible temporal resolution. Combined recordings from the nearest five broadband stations are analyzed for a time period of 6 months framing the main shock. We observe a coseismic velocity decrease of up to 0.76% in the vicinity of the main shock in the frequency range of 0.05–0.3 Hz. The velocity drop is largest at close proximity to the earthquake hypocenter and decreases systematically with distance. We also find a correlation between coseismic velocity decrease and the amount of coseismic slip on the rupture plane. The observed velocity drop shows the drastic response of the brittle crust in response to a major earthquake.