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Changes in electrical resistivity track changes in tectonic plate coupling
Author(s) -
Heise Wiebke,
Caldwell T. Grant,
Bertrand Edward A.,
Hill Graham J.,
Bennie Stewart L.,
Ogawa Yasuo
Publication year - 2013
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 - 10.1002/grl.50959
Subject(s) - subduction , geology , coupling (piping) , magnetotellurics , electrical conductor , electrical resistivity and conductivity , tectonics , geophysics , seismology , petrology , materials science , composite material , engineering , electrical engineering
Interplate coupling on the Hikurangi subduction margin along the east coast of New Zealand's North Island changes north to south from almost uncoupled to locked. Clay‐rich sediments and aqueous fluids at the subduction interface have been invoked as key factors in the frictional processes that control interplate coupling. Here we use magnetotelluric data to show that the subduction interface in the weakly coupled region is electrically conductive but is resistive in the locked region. These results indicate the presence of a layer of fluid‐ and clay‐rich sediments in the weakly coupled region and support the idea that the presence of fluid and hydrated clays at the interface is a major factor controlling plate coupling.