23 November, 2011, 5 Merrion Square, Dublin 2

Speaker: Stephane Rodenay, University of Bergen, Norway
Title: A seismological perspective on water in subduction zones

Abstract:

Subduction zones transport water into the Earth’s interior. The subsequent release of this water through dehydration reactions can trigger intraslab earthquakes and arc volcanism, regulate slip on the plate interface, control plate buoyancy, and regulate the planet’s surface water budget on long time scales. Here, we discuss how high-resolution seismic images of subduction zones, when considered in conjunction with petrological and geodynamical results, can improve our understanding of these processes by characterizing water transport and distribution in these systems. Using examples from Cascadia and southern Alaska, we show that seismic images can place robust constraints on the location of dehydration reactions in the subducted crust and on the fate of water released in the mantle wedge.