Cornell University
Library
Cornell UniversityLibrary

eCommons

Help
Log In(current)
  1. Home
  2. Cornell University Graduate School
  3. Cornell Theses and Dissertations
  4. EARTHQUAKES IN THE CONTINENTAL CRUST

EARTHQUAKES IN THE CONTINENTAL CRUST

File(s)
StephanieDevlin-CornellUniversityDissertation.pdf (92.49 MB)
Permanent Link(s)
https://hdl.handle.net/1813/11127
Collections
Cornell Theses and Dissertations
Author
Devlin, Stephanie
Abstract

Continental earthquakes are one of the most widely observable indicators of on-going continental lithospheric deformation. Accurate earthquake depth estimates are critical to tectonic interpretations, yet depths are not reliably provided by global earthquake catalogs and bulletins. Therefore, separate analyses are needed to determined accurate earthquake depths. In this thesis, I compile accurate estimates of continental earthquake depths and combine them with complementary datasets, such as topography, subsurface structural interpretations, and lithospheric thickness estimates, to investigate continental deformation.

I present results of focal mechanisms and accurate depth estimates for continental earthquakes throughout the Central Andes of South America. Through integration with high resolution topographic data and interpretations of subsurface structures, I find the following: (1) earthquakes in the foreland and Eastern Cordillera are consistently associated with basement-involved deformation, (2) earthquake focal mechanism P axis orientations indicate an east-west crustal shortening direction in the forelands, (3) local orientations of deformational structures influence earthquake focal mechanism orientation, and (4) normal and strike-slip focal mechanisms beneath southern Peru and northernmost Chile are consistent with the effects of the increase in vertical compressive stress, due to high topography and thick crustal root of the plateau, superimposed on the stress orientations seen in the foreland.

I also conduct a global study of the depth distributions of continental earthquakes by synthesizing previously reported accurate earthquake depth determinations to investigate in what tectonic settings lower crustal earthquakes occur in an attempt to understand their significance to lithospheric strength and deformation. I find that deep continental crustal earthquakes occur within stable lithosphere and within tectonically active lithosphere at a transitional state of lithospheric thickness and crustal deformation.

Date Issued
2008-07-23T15:33:07Z
Keywords
earthquakes
•
continental crust
Type
dissertation or thesis

Site Statistics | Help

About eCommons | Policies | Terms of use | Contact Us

copyright © 2002-2026 Cornell University Library | Privacy | Web Accessibility Assistance