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Plate interaction in the NE Caribbean subduction zone from continuous GPS observations

Geophysical Research Letters

By:
and
DOI: 10.1029/2012GL051485

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Abstract

Kinematic similarities between the Sumatra and Puerto Rico Trenches highlight the potential for a mega-earthquake along the Puerto Rico Trench and the generation of local and trans-Atlantic tsunamis. We used the horizontal components of continuous GPS (cGPS) measurements from 10 sites on NE Caribbean islands to evaluate strain accumulation along the North American (NA) - Caribbean (CA) plate boundary. These sites move westward and slightly northward relative to CA interior at rates ≤2.5 mm/y. Provided this motion originates in the subduction interface, the northward motion suggests little or no trench-perpendicular thrust accumulation and may in fact indicate divergence north of Puerto Rico, where abnormal subsidence, bathymetry, and gravity are observed. The Puerto Rico Trench, thus, appears unable to generate mega-earthquakes, but damaging smaller earthquakes cannot be discounted. The westward motion, characterized by decreasing rate with distance from the trench, is probably due to eastward motion of CA plate impeded at the plate boundary by the Bahamas platform. Two additional cGPS sites in Mona Passage and SW Puerto Rico move to the SW similar to Hispaniola and unlike the other 10 sites. That motion relative to the rest of Puerto Rico may have given rise to seismicity and normal faults in Mona Rift, Mona Passage, and SW Puerto Rico.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Plate interaction in the NE Caribbean subduction zone from continuous GPS observations
Series title:
Geophysical Research Letters
DOI:
10.1029/2012GL051485
Volume
39
Year Published:
2012
Language:
English
Publisher:
American Geophysical Union
Publisher location:
Washington, D.C.
Contributing office(s):
Woods Hole Coastal and Marine Science Center
Description:
6 p.; L10304
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geophysical Research Letters
Number of Pages:
6
Other Geospatial:
Cariibbean