Abstract
The amount of water in the Earth's deep mantle is critical for the evolution of the Earth. Mineral physics studies revealed that the mantle transition zone can store several times the volume of water in an ocean. However, the actual water distribution in the transition zone remains enigmatic. We used the highest resolution images produced of scatterers in the North-American transition zone derived from teleseismic data recorded by the Earthscope Transportable Array. We find that the transition zone is filled with previously unrecognized small-scale heterogeneities that produce pervasive, negative polarity signals. Simulations demonstrated the images can be explained by low-velocity bodies shaped as distributed blobs or near vertical structures. We suggest these low-velocity bodies may be heterogeneously distributed, water-enriched subducted harzburgites produced through long-term accumulation.
Original language | English (US) |
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Pages (from-to) | 42-50 |
Number of pages | 9 |
Journal | Earth and Planetary Science Letters |
Volume | 505 |
DOIs | |
State | Published - Jan 1 2019 |
Keywords
- imaging
- mantle convection
- mantle transition zone
- receiver functions
ASJC Scopus subject areas
- Geophysics
- Geochemistry and Petrology
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science