HR: 16:15h
AN: S44B-02 INVITED    [Abstracts]
TI: USArray Enables Improved Resolution Studies of Earth's Upper and Lower Mantle
AU: * Garnero, E J
EM: garnero@asu.edu
AF: Arizona State University, School of Earth and Space Exploration, Tempe, AZ 85287-1404, United States
AU: Lay, T
EM: thorne@pmc.ucsc.edu
AF: University of California, Earth and Planetary Sciences, Santa Cruz, CA 95064, United States
AB: The first full deployment of EarthScope's USArray has now been completed, with over 400 high-quality broadband stations distributed over a 70-km grid covering the western U.S. The openly-available USArray data can be obtained in near real-time using convenient IRIS-hosted data retrieval tools (e.g., SOD, JWeed). The dramatic increase in number of seismograms for each event, along with the unusual combination of large aperture and dense wave field sampling, are enabling improved resolution of deep Earth structure in diverse applications. Automation is now important for most initial data processing steps, in order to handle the large numbers of records that quickly accumulate. We highlight several applications of USArray data to Earth structure investigations in locations remote from North American lithosphere where the bulk of applications are focused. Earthquake source distributions relative to the USArray define several target study regions. For example, deep focus South American and Fiji-Tonga earthquakes allow high-resolution analyses of lower mantle structure beneath the Cocos Plate and the central Pacific, respectively. The increasingly detailed models that are inferred have many thermal, compositional and dynamical implications. Fiji-Tonga events recorded by USArray are enabling detailed mapping of upper mantle discontinuity structures in the vicinity of the Tonga slab. Images of upper mantle discontinuities beneath South America and Hawaii are brought into sharper focus using teleseismic data recorded by USArray. Various data processing approaches, such as stacking, migration, and source wavelet deconvolution are now stabilized by the dense USArray data sets. The increasingly detailed characterization of deep structure is motivating both advances in 3D wave propagation methods and collaborative interdisciplinary efforts to provide viable interpretations.
DE: 7200 SEISMOLOGY
DE: 7203 Body waves
DE: 7208 Mantle (1212, 1213, 8124)
DE: 7240 Subduction zones (1207, 1219, 1240)
DE: 7294 Seismic instruments and networks (0935, 3025)
SC: Seismology [S]
MN: 2007 Fall Meeting