The nature of subslab slow velocity anomalies beneath South America
AffiliationUniv Arizona, Dept Geosci
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationThe nature of subslab slow velocity anomalies beneath South America 2017, 44 (10):4747 Geophysical Research Letters
JournalGeophysical Research Letters
Rights©2017. American Geophysical Union. All Rights Reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractSlow 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.
Note6 month embargo; First published: 21 May 2017
VersionFinal published version
SponsorsNSF [EAR-1415914, EAR-1565475]