Publication Date:
2013-10-04
Description:
[1] Using multiple ScS reverberations we examine mantle reflectivity structure beneath northeast China and the northwest Pacific. We find several upper mantle discontinuities, including a melt layer with a mean thickness of 64 km atop the 410-km discontinuity, present on both sides of the subducting slab near the Nankai trench. The transition zone contains a split 520-km discontinuity in several paths, and tomographic images show stagnant slabs at this depth. We believe this may be slab-related based on experimental work (Saikia, A., Frost, D. J., Rubie, D. C., 2008. Splitting of the 520-kilometer seismic discontinuity and chemical heterogeneity in the mantle. Science 319 (5869), 1515–1518). A negative reflector is found in one path beneath the northeast China craton at a depth of 598 km. Mid-mantle reflectors are found in all of our paths and are present throughout a wide depth range (~750 – 1600 km).
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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