CAREER: Advanced Subsurface Imaging Across USArray and Intermountain Seismic Belt Using Dense Seismic Arrays

University Of Utah, Salt Lake City UT

Investigators

Abstract

This project will support big data seismology research on both continental and local scales. The focus of the research is to advance current seismic imaging methods aimed at achieving an unprecedented resolution to better determine interior earth structure. On the continental scale, the research will leverage data collected through the community-driven seismic experiment, namely the EarthScope USArray, to construct 3D crustal and upper mantle models beneath the contiguous United States and Alaska. The 3D models will be used to better understand the tectonic processes such as the basin formation, mountain building, and volcanic and earthquake activities. On the local scale, temporary seismic arrays will be deployed within Yellowstone National Park and around Salt Lake City to better determine the magmatic and basin structures, respectively. The detailed crustal structures revealed by this study will lead to better understanding of the potential volcanic and earthquake hazards within these areas. Through the research, the project will support undergraduate and graduate education as well as the development of K-12 educational earth science materials that address the Next Generation Science Standards. This project targets two lines of research related to advanced array imaging utilizing large N seismic arrays. First, using USArray data, the project aims to advance the current broadband ambient noise and surface wave tomography methods to resolve 3D velocity and density structure simultaneously by jointly inverting surface wave dispersion, Rayleigh wave ellipticity, surface wave amplification, and receiver function measurements. Moreover, the enigmatic 1-psi apparent anisotropy signals observed using directionally dependent measurements will be studied to better determine the sharpness of physiographic boundaries. The velocity and density model constructed in this project will be used to evaluate the nature of the major tectonic processes in the North America. Second, the project will support the deployment of large-N nodal geophone arrays in several locations within the Intermountain Seismic Belt (ISB). Two locations, Yellowstone and Salt Lake Valley, will be of particular interest in this study. By applying ambient noise tomography and receiver function analysis and using different dense array configurations, the project aims to resolve the precise geometries of the Yellowstone magma camber and the Salt Lake Basin, which are of great importance to the determination of the regional volcanic and seismic hazards, respectively. Broader impacts will support undergraduate and graduate education. They include developing earth science materials at the K-12 level that are in line with the Next Generation Science Standards. In addition, the PI will work with the Yellowstone National Park to inform the myriad of visitors to the park on the new scientific findings from this research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.