A global study of double seismic zones and its implications for the mechanism of intermediate-depth earthquakes

The fundamental physical processes to generate earthquakes contradict the occurrence of intermediate-depth (80-350 km) seismicity: both pressure and temperature increase with depth, which inhibits fracture, unstable sliding, and promotes ductile flow. Classic experiments on olivine, the main mineral that composes the mantle, show that the shear stresses necessary to overcome the high normal stresses imposed by the overburden pressure are unsustainable at these depths. In subduction zones, the dehydration of the descending oceanic lithosphere might enable the observed brittle-like behavior; but this hypothesis remains controversial, as there are other viable alternatives. Improving our understanding of the intermediate-depth seismicity relies on assembling accurate and systematic seismological observations, which I tackle here in my graduate work. First, I developed a relocation method that uses array processing in such a way that velocity model biases are reduced.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Florez Torres, Manuel Alberto.

Advisor dc:contributor.advisor

• German A. Prieto.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/123736

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/123736