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Single station CMT; Application to the Michoacan, Mexico, Earthquake of September 19, 1985
Author(s) -
Ekström Göran,
Dziewonski Adam M.,
Steim Joseph M.
Publication year - 1986
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/gl013i003p00173
Subject(s) - moment tensor , seismology , geology , centroid , geodesy , seismic moment , moment (physics) , subduction , earth structure , moment magnitude scale , scalar (mathematics) , physics , geometry , fault (geology) , mathematics , oceanography , deformation (meteorology) , classical mechanics , scaling , tectonics
Observations of three‐dimensional ground motion at a single point on the surface of the Earth following an earthquake can be sufficient to determine the zeroth order moment tensor of the event. We adapt the centroid‐moment tensor (CMT) method [Dziewonski et al., 1981] of analysis to single station data and apply it to the September 19, 1985 Michoacan earthquake. The obtained mechanism indicates faulting on a shallow plane, consistent with the ongoing subduction of the Cocos plate. The scalar moment is 1.3 × 10 28 dyne‐cm. A direct deconvolution of the observed P‐wave train indicates that the moment release occurred in two subevents, each of 20 seconds duration with a peak‐to‐peak separation in time of 25 seconds.