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Title: Inferring Earth’s discontinuous chemical layering from the 660-kilometer boundary topography
Topography, or depth variation, of certain interfaces in the solid Earth can provide important insights into the dynamics of our planet interior. Although the intermediate- and long-range topographic variation of the 660-kilometer boundary between Earth’s upper and lower mantle is well studied, small-scale measurements are far more challenging. We found a surprising amount of topography at short length scale along the 660-kilometer boundary in certain regions using scattered P'P' seismic waves. Our observations required chemical layering in regions with high short-scale roughness. By contrast, we did not see such small-scale topography along the 410-kilometer boundary in the upper mantle. Our findings support the concept of partially blocked or imperfect circulation between the upper and lower mantle.  more » « less
Award ID(s):
1736046
PAR ID:
10108768
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Science
Volume:
363
Issue:
6428
ISSN:
0036-8075
Page Range / eLocation ID:
736 to 740
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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