Japan Geoscience Union Meeting 2015

Presentation information

International Session (Oral)

Symbol S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Techtonophysics

[S-IT04] Rheology of Earth's Interior

Thu. May 28, 2015 12:00 PM - 12:45 PM 106 (1F)

Convener:*Tomohiro Ohuchi(Geodynamics Research Center, Ehime University), Shun-ichiro Karato(Yale University, Department of Geology and Geophysics), Katsuyoshi Michibayashi(Institute of Geosciences, Shizuoka University), Chair:Tomohiro Ohuchi(Geodynamics Research Center, Ehime University)

12:30 PM - 12:45 PM

[SIT04-05] Supply rate of continental materials by subduction of island arcs

*Hiroki ICHIKAWA1, Kenji KAWAI2, Shinji YAMAMOTO2, Masanori KAMEYAMA1 (1.Geodynamics Research Center, Ehime University, 2.Graduate School of Arts and Sciences, The University of Tokyo)

Keywords:continental crust, island arc, mantle, subduction, rheology

Evolution of life on the Earth is strongly related to the oceans and the continents, both of which are unique to the Earth. Continental materials contain a large amount of incompatible and radiogenic elements, which may affect terrestrial thermal history and chemical evolution, as well as the Earth's surface environment. Geological studies have revealed that continental materials subduct from the Earth's surface via the following three mechanisms: tectonic erosion, sediment subduction, and direct subduction of immature oceanic arcs, which are found, for example, in the western Pacific. In the first two processes, the continental materials are conveyed through subduction channels of thickness of 2-3km just above the subducting slabs. Here, in order to estimate the supply rate of continental materials of oceanic arcs to the deep mantle, we have conducted numerical simulations of subduction of arcs based on the finite element method, using relevant rheology models. The results show that the subduction rate highly depends on temperature profiles of the subducting slabs and the size of the arcs.