Seismic imaging of transition zone discontinuities suggests hot mantle west of Hawaii
Cao, Q.; van der Hilst, R.D.; de Hoop, M.V.; Shim, S.-H. (2011). Seismic imaging of transition zone discontinuities suggests hot mantle west of Hawaii. Science (Wash.) 332(6033): 1068-1071. https://dx.doi.org/10.1126/science.1202731
In: Science (Washington). American Association for the Advancement of Science: New York, N.Y. ISSN 0036-8075; e-ISSN 1095-9203, meer
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| Auteurs | | Top |
- Cao, Q.
- van der Hilst, R.D.
- de Hoop, M.V.
- Shim, S.-H.
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| Abstract |
The Hawaiian hotspot is often attributed to hot material rising from depth in the mantle, but efforts to detect a thermal plume seismically have been inconclusive. To investigate pertinent thermal anomalies, we imaged with inverse scattering of SS waves the depths to seismic discontinuities below the Central Pacific, which we explain with olivine and garnet transitions in a pyrolitic mantle. The presence of an 800- to 2000-kilometer-wide thermal anomaly (Delta T(max) similar to 300 to 400 kelvin) deep in the transition zone west of Hawaii suggests that hot material does not rise from the lower mantle through a narrow vertical plume but accumulates near the base of the transition zone before being entrained in flow toward Hawaii and, perhaps, other islands. This implies that geochemical trends in Hawaiian lavas cannot constrain lower mantle domains directly. |
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