Geophysical Studies of Plate-Boundary Earthquakes and Mid-Plate Volcanism in theOcean Basins

摘要

Both gravity and seismic reflection data can be used to constrain the response ofoceanic lithosphere to loading by intraplate volcanoes. Analysis of gravity data from Cretaceous seamounts in the Northwest Pacific demonstrates that the strength of the Pacific lithosphere at the time that the volcanoes erupted was less than predicted by standard thermal plate models. Seismic reflection data from the Marquesas Islands in French Polynesia, a modern-day analogue of the geologic setting in which the northwest Pacific seamounts formed, demonstrate that volcanic underplating of the crust creates another volcanic load which pushes the lithosphere up from below, leading to an anomalously shallow flexural moat. (AN).