Thermal stresses, differential subsidence, and flexure at oceanic fracture zones
作者:
Pål Wessel,
William F. Haxby,
期刊:
Journal of Geophysical Research: Solid Earth
(WILEY Available online 1990)
卷期:
Volume 95,
issue B1
页码: 375-391
ISSN:0148-0227
年代: 1990
DOI:10.1029/JB095iB01p00375
数据来源: WILEY
摘要:
Geosat geoid undulations over four Pacific fracture zones have been analyzed. After correcting for the isostatic thermal edge effect, the amplitudes of the residuals are shown to be proportional to the age offset. The shape of the residuals seems to broaden with increasing age. Both geoid anomalies and available ship bathymetry data suggest that slip must sometimes occur on the main fracture zone or secondary faults. Existing models for flexure at fracture zones cannot explain the observed anomalies. A combination model accounting for slip and including flexure from thermal stresses and differential subsidence is presented. Our model accounts for lateral variations in flexural rigidity from brittle and ductile yielding due to both thermal and flexural stresses and explains both the amplitudes and the shape of the anomalies along each fracture zone. The best fitting models have mechanical plate thicknesses that are described by the depth to the 600°–700°C isothe
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