Slow seismic velocity anomalies are commonly imaged beneath subducting slabs in tomographic studies, yet a unifying explanation for their distribution has not been agreed upon. In South America two such anomalies have been imaged associated with subduction of the Nazca Ridge in Peru and the Juan Fernandez Ridge in Chile. Here we present new seismic images of the subslab slow velocity anomaly beneath Chile, which give a unique view of the nature of such anomalies. Slow seismic velocities within a large hole in the subducted Nazca slab connect with a subslab slow anomaly that appears correlated with the extent of the subducted Juan Fernandez Ridge. The hole in the slab may allow the subslab material to rise into the mantle wedge, revealing the positive buoyancy of the slow material. We propose a new model for subslab slow velocity anomalies beneath the Nazca slab related to the entrainment of hot spot material.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/625047 |
| Date | 28 May 2017 |
| Creators | Portner, Daniel Evan, Beck, Susan, Zandt, George, Scire, Alissa |
| Contributors | Univ Arizona, Dept Geosci, Department of Geosciences; University of Arizona; Tucson Arizona USA, Department of Geosciences; University of Arizona; Tucson Arizona USA, Department of Geosciences; University of Arizona; Tucson Arizona USA, IRIS PASSCAL Instrument Center; New Mexico Institute of Mining and Technology; Socorro New Mexico USA |
| Publisher | AMER GEOPHYSICAL UNION |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | ©2017. American Geophysical Union. All Rights Reserved. |
| Relation | http://doi.wiley.com/10.1002/2017GL073106 |
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