Publication Date:
2020-05-01
Description:
Body waves can be extracted from correlation functions computed from seismic records even at teleseismic distances. Here we propose to use P and PcP waves from the secondary microseism frequency band that are propagating between Europe and the Eastern US to image the Core-Mantle Boundary (CMB) and D’ structure beneath the North Atlantic. This study presents the first 3D image of the lower mantle obtained from ocean-generated microseism data. Robustness of our results is evaluated by comparing images produced by propagation in both directions. Our observations reveal complex patterns of lateral and vertical variations of P-wave reflectivity with a particularly strong anomaly extending upward in the lower mantle up to 2600 km deep. We compare these results with synthetic data and associate this anomaly to a Vp velocity increase above the CMB. Our image aims at promoting the study of the lower mantle with microseism noise excitations.
Print ISSN:
0956-540X
Electronic ISSN:
1365-246X
Topics:
Geosciences