EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Satake 1994
Satake, K. (1994). Mechanism of the 1992 Nicaragua Tsunami Earthquake. Geophysical Research Letters 21: doi: 10.1029/94GL02338. issn: 0094-8276.

The 1992 Nicaragua earthquake generated larger tsunamis than expected from its surface wave magnitude (MS 7.2) and is known as a 'tsunami earthquake'. Seismological studies showed that the duration was very long for its size, about 100 s. Other studies have shown that the seismic moment estimated from tsunamis is an order of magnitude larger than that from seismic waves, even after the long duration is accounted for. Numerical computations of tsunamis from various fault models are made to reconcile this discrepancy. Comparison of calculated waveforms with tide gauge records show that the fault width is 40 km, much narrower than the aftershock area, and extends only into the upper 10 km of the ocean bottom. Slip amount on the fault is estimated to be 3 m from amplitude comparisons. The fault length is estimated to be 250 km, slightly longer than the aftershock area, from comparison of the tsunami height distribution. The rigidity around the shallow fault may be smaller than that of a standard underthrust fault, and the seismic moment is estimated as 3¿1020 Nm, consistent with the seismic observations. A slow rupture on the shallow fault, presumably in the subducted sediments, is responsible to the unusually large tsunami excitation. ¿ American Geophysical Union 1994

BACKGROUND DATA FILES

Abstract

Keywords
Oceanography, Physical, Tsunamis and storm surges, Seismology, Earthquake parameters, Seismology, General or miscellaneous, Tectonophysics, Plate boundary structures and processes
Journal
Geophysical Research Letters
http://www.agu.org/journals/gl/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit