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Characterization of aftershock‐fault plane orientations of the 1999 İzmit (Turkey) earthquake using high‐resolution aftershock locations
Author(s) -
Bulut Fatih,
Bohnhoff Marco,
Aktar Mustafa,
Dresen Georg
Publication year - 2007
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 - 10.1029/2007gl031154
Subject(s) - aftershock , geology , seismology , fault plane , geodesy , hypocenter , inversion (geology) , high resolution , focal mechanism , induced seismicity , fault (geology) , remote sensing , tectonics
Joint inversion for hypocentral parameters and the velocity field is nowadays a state of the art tool to obtain high‐resolution images of seismically active regions. In this study, we focus on the location accuracy of aftershocks of the 1999 Mw = 7.4 İzmit (NW Turkey) earthquake. We obtained a new velocity model for the region, and depicted its improvement on absolute locations in terms of uncertainty and misfit. Two well‐developed aftershock clusters located in the Akyazı area and Karadere‐Düzce region, were analyzed in detail based on a waveform cross‐correlation approach that allowed improving the location accuracy by a factor of 6. Relocation results reveal that hypocenters form narrow planes of activity that can be correlated with focal mechanisms of the larger aftershocks as well as nearby clouds of activity with no internal structure down to the resolved scale of ∼300 m.