Premium
Low stress drop earthquakes in the rupture zone of the 1992 Nicaragua tsunami earthquake
Author(s) -
Bilek Susan L.,
Rotman Holly M. M.,
Phillips W. Scott
Publication year - 2016
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 - 10.1002/2016gl070409
Subject(s) - seismology , geology , tsunami earthquake , seismic moment , seismic zone , moment magnitude scale , earthquake magnitude , slow earthquake , earthquake rupture , magnitude (astronomy) , interplate earthquake , fault (geology) , induced seismicity , foreshock , aftershock , scaling , physics , geometry , mathematics , astronomy
Tsunami earthquakes, events that generate larger than expected tsunami and are deficient in high‐frequency seismic radiation, are rare but hazardous to coastal populations. One model for these events is shallow rupture through low‐strength materials. We calculate seismic moment, corner frequency, and stress drop for 216 earthquakes (2.1 < M w < 4.7, November 2005 to June 2006) within and external to the 1992 Nicaragua tsunami earthquake rupture zone to test the hypothesis that differences in fault zone properties defined the limits of the 1992 tsunami rupture zone and continue to produce spatial variations in earthquake source properties. Mean stress drop of events within the rupture area is 1.2 MPa, and 5.5 MPa for events just outside of the rupture zone, with similar magnitude earthquakes in each group. Our results demonstrate different source parameter characteristics for microseismicity in the region of a past tsunami earthquake.