Seismic Autocorrelation to Explore Subglacial Crustal Structure
Description:
Recent advances in autocorrelation of teleseismic waves enable a new approach to study subglacial geologic structure in Greenland and Antarctica, capable of producing new estimates of crustal thickness and the first crustal P-wave velocity estimates using the timing of Pmp arrivals. Ice-rock interfaces at the bases of ice sheets generate high-amplitude ice multiples that mask subtler concurrent arrivals that are useful for studying crustal structure, such as the Pms phase typically identified in receiver function analysis. These multiples have hindered previous receiver function studies of subglacial crustal structure, forcing them to use more uncertain methods, such as identifying crustal multiple arrivals. We autocorrelated over twenty years of teleseismic earthquake records from stations in Greenland and Antarctica and developed a suite of forward models to compare our results to. We demonstrate that autocorrelation can resolve the Pmp phase through ice sheets at certain stations and use the arrival timing of this phase to directly estimate crustal thickness and P-wave velocity at select sites in Greenland and Antarctica. We additionally find that the Pmp phase is absent in data collected at some stations, implying either unexplained amplitude losses in these Moho arrivals or a diffuse crust-mantle boundary.
Session: Earth’s Structure From the Crust to the Core [Poster]
Type: Poster
Date: 4/18/2023
Presentation Time: 08:00 AM (local time)
Presenting Author: Rishi Chandra
Student Presenter: Yes
Invited Presentation:
Authors
Rishi Chandra Presenting Author Corresponding Author chandra@arizona.edu University of Arizona |
Daniella DellaGiustina danidg@lpl.arizona.edu University of Arizona |
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Seismic Autocorrelation to Explore Subglacial Crustal Structure
Category
Earth’s Structure From the Crust to the Core