Structure and Evolution of the Oceanic Lithosphere-Asthenosphere System from High-Resolution Surface-Wave Imaging ...

• Main Author: Russell, Joshua Berryman
• Format: Text
• Language: unknown
• Published: Columbia University 2021
• Subjects: Geophysics; FOS: Earth and related environmental sciences; Submarine geology; Lithosphere; Surface waves Oceanography; Sea-floor spreading; Pacific; Orca
• Online Access: https://dx.doi.org/10.7916/d8-33w6-f908; https://academiccommons.columbia.edu/doi/10.7916/d8-33w6-f908

In this thesis, I investigate the seismic structure of oceanic lithosphere and asthenosphere with a particular focus on seismic anisotropy, using high-resolution surface waves recorded on ocean-bottom seismometers (OBS) in the Pacific and Atlantic Oceans. The NoMelt (~70 Ma) and Young OBS Research into Convecting Asthenosphere (ORCA) (~43 Ma) OBS experiments located in the central and south Pacific, respectively, provide a detailed picture of ``typical'' oceanic lithosphere and asthenosphere and offer an unprecedented opportunity to investigate the age dependence of oceanic upper mantle structure. The Eastern North American Margin Community Seismic Experiment (ENAM-CSE) OBS array located just offshore the Eastern U.S. captures the transition from continental rifting during Pangea to normal seafloor spreading, representing significantly slower spreading rates. Collectively, this work represents a diverse set of observations that improve our understanding of seafloor spreading, present-day mantle dynamics, and ...