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Melting in the deep upper mantle oceanward of the Honshu slab
- Source :
-
Physics of the Earth & Planetary Interiors . Jul2009, Vol. 175 Issue 3/4, p137-144. 8p. - Publication Year :
- 2009
-
Abstract
- Abstract: We examine the upper mantle and transition zone beneath the western Pacific using multiple ScS reverberations. A low-velocity zone (LVZ) is found above the 410-km discontinuity oceanward of the subducting Honshu slab at an average depth of 356km, with a thickness that ranges from 50 to 75km assuming the LVZ continues to the 410-km discontinuity, which is locally elevated. The low-velocity region is evident in previous tomographic studies, and our results suggest that the anomaly is best explained by a layer of partial melt. The layer may be entrained from above by subduction or produced in situ by the combined effects of water and temperature. A self-consistent model that explains local P-wave velocities (Obayashi, M., Sugioka, H., Yoshimitsu, J., Fukao, Y., 2006. High temperature anomalies oceanward of subducting slabs at the 410-km discontinuity. Earth and Planetary Science Letters 243, 149–158) and our observations calls for a maximum temperature anomaly of ∼150°C and a resulting maximum olivine water content after melting of 0.100wt. %. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 00319201
- Volume :
- 175
- Issue :
- 3/4
- Database :
- Academic Search Index
- Journal :
- Physics of the Earth & Planetary Interiors
- Publication Type :
- Academic Journal
- Accession number :
- 39783125
- Full Text :
- https://doi.org/10.1016/j.pepi.2009.03.007