Detection of a ULVZ at the base of the mantle beneath the northwest Pacific
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چکیده
[1] We used the Yellowknife seismic array (YKA) to measure the slowness of 1,371 P and Pdiff waves from earthquakes occurring in the circum-Pacific region. The corresponding anomalies in P-velocity show a sharp reduction of up to 6% across a patch of the lowermost mantle beneath the Northwest Pacific with lateral dimensions of several hundred kilometers. The location of this ultra low velocity zone (ULVZ) correlates with a longwavelength compositional boundary revealed by probabilistic mantle tomography. We interpret the ULVZ as partial melt created by paleo-slab material that is being swept laterally from northwestern Pacific subduction zones towards the large, chemically distinct province beneath the south-central Pacific. Citation: Xu, Y., and K. D. Koper (2009), Detection of a ULVZ at the base of the mantle beneath the northwest Pacific, Geophys. Res. Lett., 36, L17301, doi:10.1029/2009GL039387.
منابع مشابه
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تاریخ انتشار 2009