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Pacific Plate deformation from horizontal thermal contraction

Corne Kreemer and Richard G. Gordon
Pacific Plate deformation from horizontal thermal contraction
Geology (Boulder) (October 2014) 42 (10): 847-850


The central approximation of plate tectonics is that the plates are rigid, which gives the theory its rigor and predictive power. Space geodetic measurements are consistent with the rigidity of stable plate interiors, but some failures of plate-circuit closure, in particular of oceanic plates, indicate that plates may be measurably non-rigid. We explore the hypothesis that horizontal thermal contraction causes deformation of oceanic plates. Here we show significant expected displacement fields due to thermal contraction for the Pacific plate based on a previously proposed relationship between seafloor age and strain rate and on two end-member assumptions on how strain compatibility is enforced. The predicted maximum 2.2 mm/yr southeastward motion of the northeastern part of the plate relative to the Pacific-Antarctic Rise may contribute to a large part of the non-closure of the Pacific-North America plate motion circuit. Our predicted displacement rates cannot (yet) be confirmed by current space geodetic data and will require seafloor geodesy with 1 mm/yr accuracy. The spatial distribution of predicted moment rate agrees reasonably well with that of intraplate earthquake epicenters, similar to what is observed for plate boundary zones. Our results suggest that plate-scale horizontal thermal contraction is significant, and that it may be partly released seismically.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 42
Serial Issue: 10
Title: Pacific Plate deformation from horizontal thermal contraction
Affiliation: University of Navada, Reno, Nevada Bureau of Mines and Geology, Reno, NV, United States
Pages: 847-850
Published: 201410
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 26
Accession Number: 2014-082849
Categories: Solid-earth geophysics
Document Type: Serial
Bibliographic Level: Analytic
Annotation: GSA Data Repository item 2014301
Illustration Description: illus.
Secondary Affiliation: Rice University, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201443
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