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Source mechanisms of the June 7, 1982 Ometepec, Mexico Earthquake
Author(s) -
Beroza G.,
Rial J. A.,
McNally K. C.
Publication year - 1984
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/gl011i008p00689
Subject(s) - seismology , geology , subduction , seismogram , trench , tectonics , tsunami earthquake , chemistry , organic chemistry , layer (electronics)
Body wave synthetic seismograms are used to study the source parameters and rupture time history of the doublet of large (M S = 6.9, 7.0) earthquakes which occurred within five hours of one another near the town of Ometepec, Mexico on June 7, 1982. The events are thrust events consistent with the subduction of the Cocos Plate beneath the North America plate. Our results indicate that these are not the simple, single source events previously thought to be typical of the Middle America Trench in this region. While the first event had a simple source time function, the second did not. This relatively complex behavior can not be explained by any tectonic complications that have been proposed to account for the complexity of the 1970 Chiapas earthquake and the 1973 Colima earthquake. Multiple earthquake sequences in 1962, 1950, and 1928 have occurred in the general area of the two 1982 Ometepec earthquakes suggesting that earthquake doublets are characteristic of this region.