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- Geoffrey A. Abers
- Department of Earth Sciences Boston University Boston MA USA
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- Terry Plank
- Department of Earth Sciences Boston University Boston MA USA
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- Bradley R. Hacker
- Department of Geological Sciences University of California Santa Barbara CA USA
書誌事項
- 公開日
- 2003-01
- 権利情報
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- http://onlinelibrary.wiley.com/termsAndConditions#vor
- DOI
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- 10.1029/2002gl015649
- 公開者
- American Geophysical Union (AGU)
この論文をさがす
説明
<jats:p>Nicaraguan volcanoes show globally high concentrations of geochemical tracers from dehydration of subducting crust, which may reflect a slab with unusually high amounts of H<jats:sub>2</jats:sub>O. To test this possibility, we measure seismic velocities at the top of the subducted plate and compare them with predictions for hydrated mafic rocks. Regional seismic <jats:italic>P</jats:italic> waves for intraslab events at 100–150 km depth show a high‐frequency late arrival, apparently trapped in a low‐velocity waveguide 2.5–6 km thick at the top of the downgoing plate, 14.5 ± 2.2% slower than surrounding mantle. The velocities can be explained by ≥5 wt % H<jats:sub>2</jats:sub>O in the subducted crust, 2–3 times the hydration inferred for other slabs by similar methods. This interpretation implies extensive hydration of the Cocos Plate off Nicaragua, perhaps enhanced by up‐dip fluid flow within the slab at >100 km depth.</jats:p>
収録刊行物
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- Geophysical Research Letters
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Geophysical Research Letters 30 (2), 1098-, 2003-01
American Geophysical Union (AGU)