Shear-Wave Splitting and Implications for Mantle Flow Beneath the MELT Region of the East Pacific Rise
- 22 May 1998
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 280 (5367) , 1230-1232
- https://doi.org/10.1126/science.280.5367.1230
Abstract
Shear-wave splitting across the fast-spreading East Pacific Rise has been measured from records of SKS and SKKSphases on the ocean-bottom seismometers of the Mantle Electromagnetic and Tomography (MELT) Experiment. The direction of fast shear-wave polarization is aligned parallel to the spreading direction. Delay times between fast and slow shear waves are asymmetric across the rise, and off-axis values on the Pacific Plate are twice those on the Nazca Plate. Splitting on the Pacific Plate may reflect anisotropy associated with spreading-induced flow above a depth of about 100 km, as well as a deeper contribution from warm asthenospheric return flow from the Pacific Superswell region.Keywords
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