Seismic consequences of warm versus cool subduction metamorphism: examples from southwest and northeast japan
Warm and cool subduction zones exhibit differences in seismicity, seismic structure, and arc magmatism, which reflect differences in metamorphic reactions occurring in subducting oceanic crust. In southwest Japan, arc volcanism is sparse and intraslab earthquakes extend to 65 kilometers depth; in northeast Japan, arc volcanism is more common and intraslab earthquakes reach 200 kilometers depth. Thermal-petrologic models predict that oceanic crust subducting beneath southwest Japan is 300 degrees to 500 degrees C warmer than beneath northeast Japan, resulting in shallower eclogite transformation and slab dehydration reactions, and possible slab melting.
Peacock
SM
Department of Geology, Arizona State University, Tempe, AZ 85287-1404, USA. Pacific Geoscience Centre, Geological Survey of Canada, Sidney, BC V8L 4B2, Canada.
Wang
K