SCEC Award Number 20072 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Deriving Shallow Structure from Colocated Broadband Seismic and Pressure Data
Name Organization
Toshiro Tanimoto University of California, Santa Barbara
Other Participants Jiong Wang (Ph.D. student, UCSB)
Yehuda Ben-Zion (USC)
Lei Qin (USC)
Sunyoung Park (Caltech)
SCEC Priorities 4b, 4a, 3g SCEC Groups Seismology, CXM, EEII
Report Due Date 03/15/2021 Date Report Submitted 03/03/2021
Project Abstract
We developed an inversion method for deriving shallow elastic structure from co-located pressure and seismic data. Such co-located stations have rapidly increased in the last 10 years, including the EarthScope Transportable Array. We have tested the method by comparing our results for Vs30 against independent Vs30 measurements by other studies. During 2020, we improved this inversion method and applied it to the EarthScope data and selected stations in Southern California.
Intellectual Merit Our inversion method for shallow elastic structure from co-located pressure and seismic data is new. The method analyzes deformation of solid Earth by surface pressure changes. We developed an algorithm for this inversion. We verified this approach by comparing our results of Vs30 against Vs30 measured by other researchers. We then applied the technique to the EarthScope TA data from 2012 to 2019 and some selected stations in Southern California that had pressure sensors between about 2000 and 2010.
Broader Impacts Detailed knowledge of shallow structure, especially in the uppermost 50-100 m, is important for earthquake hazard mitigation. This is because ground shaking amplitudes can dramatically increase if a structure contains soft layers at its top. Our method is based on an analysis of seismic noise that is generated from interactions between the atmosphere and the solid Earth. Development of this approach requires some understanding of interactions between the atmospheric and solid Earth. A graduate student is finishing his Ph.D. thesis based on this technique.
Exemplary Figure Figure 6: Vs30 at the EarthScope stations from 2012 to 2019.