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Wiemer & Benoit 1996
Wiemer, S. and Benoit, J.P. (1996). Mapping the B-value anomaly at 100 km depth in the Alaska and New Zealand Subduction Zones. Geophysical Research Letters 23: doi: 10.1029/96GL01233. issn: 0094-8276.

A positive anomaly in the frequency-magnitude distribution (b-value) is detected at approximately 90--100 km depth in two subduction zones. The b-value in this anomalous zone is 40% higher than in adjacent volumes. We use regional catalogs with a magnitude of completeness of 2.6 (Central Alaska and Cook Inlet), 2.0 (Shumagin Islands), and 3.5 (New Zealand). To resolve the b-value as a function of space in more detail, we project all earthquakes onto planes perpendicular to the strike of the slab. These cross-section views of the b-value distribution locate the high b-value anomalies at a depth of 90--100 km, on the upper surface of the Wadati-Benioff Zone. At these depths, slab dehydration may increase pore pressure, thus lowering the effective stress and increasing the b-value. Increased pore pressure would also lower the liquidus in the overlying asthenosphere, giving rise to the volcanism that occurs directly above this zone. ¿ American Geophysical Union 1996

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Abstract

Keywords
Seismology, Seismicity and seismotectonics
Journal
Geophysical Research Letters
http://www.agu.org/journals/gl/
Publisher
American Geophysical Union
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