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Estimates of fault dimensions for small earthquakes using stopping phases
Author(s) -
Imanishi Kazutoshi,
Takeo Minoru
Publication year - 1998
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 - 10.1029/98gl02185
Subject(s) - fault plane , seismology , geology , fault (geology) , earthquake swarm , swarm behaviour , earthquake location , seismic gap , submarine pipeline , aftershock , geometry , geodesy , mathematics , induced seismicity , mathematical optimization , geotechnical engineering
We propose a new method to estimate the fault dimensions of small earthquakes based on stopping phases without assuming a rupture velocity. We detected two high‐frequency stopping phases being the Hilbert transforms of each other for several earthquakes at two local stations, during an earthquake swarm at the eastern offshore of Ito in the Izu peninsula, Japan, which started on March 2, 1997. If we assume the geometry of fault to be circular, we can determine relative locations of nearest and farthest edges of the circular fault employing the difference of arrival times between these two stopping phases. Applying this method to several small earthquakes in the swarm, we succeeded in estimating the fault dimensions of these earthquakes. We also could determine the fault plane from two nodal planes by comparing the fault radii obtained at individual station.