Title: Seismic Imaging of Salt Lake Basin Sediment Using Joint Inversion of Receiver Functions and Rayleigh wave Ellipticity
Abstract: The 2020 Mw 5.7 Magna earthquake in Salt Lake City, Utah, reminded residents that the Salt Lake Valley (SLV) region is prone to damaging earthquakes from the Wasatch fault and other faults. In seismically active regions, a three-dimensional seismic velocity model is important for predicting ground-shaking hazards. The current model for the SLV area was constructed primarily from gravity data due to the limited amount of seismic data then available in the valley. Since 2018, multiple temporary geophone arrays have reduced gaps in seismic station coverage. The expanded dataset enables us to revise existing velocity models using distant earthquakes recorded by SLV seismic stations. The new velocity model from this study shows thicker sediment deposits in the northeastern SLV between the active traces of the west-dipping Wasatch fault on the east and the east-dipping West Valley fault zone on the west. Predicted gravity variations using the new velocity models show patterns consistent with the observed gravity. Moreover, our analysis shows a sharp change in sediment thickness across the Wasatch fault which is caused by movement on this fault. Our new velocity model provides a basis for revising the SLV part of the velocity model used for ground motion predictions.
Biography: HyeJeong Kim is a postdoctoral research associate at the University of Utah working with Fan-Chi Lin. Before joining the University of Utah, she earned her Ph.D. in solid earth geophysics at the Earthquake Research Institute, the University of Tokyo in 2023. She has been working on ocean bottom seismometers to image the subduction zone and oceanic plates. Currently, she is working on high-resolution imaging in various tectonic settings, including but not limited to joint analysis of surface waves and body waves recorded by large-N arrays in various sedimentary basins.
To join virtually: Zoom
Contact: hyejeong.kim@utah.edu
Website: https://sites.google.com/view/seislab/home
Recording: Zoom Recording (will be available within a week after the seminar)