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  Seismic Activity - East Pacific Rise at 22 South (September, 1996)  
 

 

 
 
epicenter image
(click to enlarge)
Plot of Earthquake Epicenters; Bathymetry is based on satellite altimetry from Smith and Sandwell. Estimated error for the site based on a numerical simulation is 7-minutes in latitude and 5 minutes in longitude.
Mean position is 22 10.55'S, 113 10.86' W. 
 

Beginning September 5, 1996, the Autonomous Hydrophone Array deployed by PMEL in the Eastern Equatorial Pacific recorded an episode of seismicity from the East Pacific Rise near 22 S and 113W. The activity continued for 3 days with a total of 165 events located.

 The location is at the northern edge of the Easter Microplate. The seismicity was originally interpreted to be of volcanic origin, but the presence of a large (Ms = 7.1) thrust mainshock recorded by the global networks indicates the activity to be an aftershock sequence.

A discussion has been published by Delouis, Nicolas, Ildefonse, and Philip, 1998, GRL, vol 25, no.9 1443-1446.

histogram Histogram of number of earthquakes recorded from the volcanic site per one-hour period.  (click to enlarge)

Listing of earthquake epicenters from the EPR at 22 S recorded September, 1996. 

 
 
Last Updated: 01/05/01

Address inquiries to:

Robert Dziak - Seismologist - robert.p.dziak@noaa.gov