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Electrical structure beneath the northern MELT line on the East Pacific Rise at 15°45′S
Author(s) -
Baba Kiyoshi,
Tarits Pascal,
Chave Alan D.,
Evans Rob L.,
Hirth Greg,
Mackie Randall L.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl027528
Subject(s) - magnetotellurics , geology , mantle (geology) , seafloor spreading , olivine , electrical resistivity and conductivity , anisotropy , geophysics , ridge , conductivity , petrology , seismology , mineralogy , paleontology , chemistry , physics , quantum mechanics , electrical engineering , engineering
The electrical structure of the upper mantle beneath the East Pacific Rise (EPR) at 15°45′S is imaged by inverting seafloor magnetotelluric data obtained during the Mantle ELectromagnetic and Tomography (MELT) experiment. The electrical conductivity model shows no evidence for a conductive region immediately beneath the ridge, in contrast to the model previously obtained beneath the EPR at 17°S. This observation can be explained by differences in current melt production along the ridge, consistent with other observations. The mantle to the east of the ridge at 60 –100 km depth is anisotropic, with higher conductivity in the spreading direction compared to the along‐strike direction, similar to the 17°S region. The high conductivity in the spreading direction can be explained by a hydrated mantle with strain‐induced lattice preferred orientation of olivine or by partial melt preferentially connected in the spreading direction.