SCEC Award Number 19137 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title SCEC5: Borehole Instrumentation Program
Investigator(s)
Name Organization
Jamison Steidl University of California, Santa Barbara
Other Participants TBN - Undergraduate Geophysics Student(s)
SCEC Priorities 3a, 4a, 1d SCEC Groups Seismology, GM, EEII
Report Due Date 04/30/2020 Date Report Submitted 08/28/2020
Project Abstract
 The borehole instrumentation program at UCSB is a continuing collaborative data gathering effort between SCEC and other agencies. We help to maintain the existing network of borehole stations in California, to facilitate the integration of this data into the regional seismic networks and the Southern California Earthquake Data Center (SCEDC), and to improve the dissemination of this data to the research community world-wide. We also seek targets of opportunity for collaborations that will augment the number of borehole stations providing publicly available data in Southern California. In the past, this program has been heavily leveraged through major funding from a single agency, with the NSF Engineering Directorate for more than a decade (2002-2014), and more recently, the Nuclear Regulatory Commission (NRC) from 2015-2017. From 2017-2019, the program was “in-between” funding and reduced funding available was spread out across multiple agencies/organizations (PG&E, SCEC, USGS, UCSB). Currently, this project is supported by DOE via a collaborative project with USC and UCSD, along with support from PG&E and UCSB. Some of the organizations the SCEC borehole instrumentation program continues to collaborate with include Caltech/USGS, ANSS/NSMP, California Geological Survey, UC San Diego HPWREN program, NSF GAGE PBO program at UNAVCO, and UC San Diego Anza network of shallow borehole sensors along the San Jacinto fault. The data gathered under this project are made available online to the public and research community, through one or more common repositories, including the UCSB geotechnical data portal, the SCEDC, and the IRIS DMC.
Intellectual Merit The borehole instrumentation program contributes to SCEC goals in a number of ways. While funded primarily as a data gathering effort, the data is useful for locating regional seismicity, and improving our understanding of crustal structure and imaging faults. Data from the borehole sensors can also provide better estimates of earthquake source properties as this data is less contaminated by the effects of the near-surface soft soil conditions. The downhole and surface data combined is also important for understanding both the linear and non-linear response of near-surface geology. They provide the baseline low-strain data, as well as more important yet less frequent large strain case histories for the study of nonlinearity. These stations are helping GMPE modelers to understand the component of uncertainty in ground motion prediction that is related to the site effect.
Broader Impacts Undergraduate and graduate students have always been, and continue to be used in the bore-hole instrumentation program for both fieldwork, and data analysis and more recently data dissemination through integration with the NEES@UCSB data portal. Matching funds from UCSB augment the funds provided from SCEC to support the students on this project. These students get hands-on experience with instrumentation and data processing and analysis techniques, a unique aspect of their education and training as the next generation seismologist and geophysicist.
Exemplary Figure Figure 1. Map of the Borehole Instrumentation in Southern California with seismic, strain, and pore pressure sensors, including SCEC/CISN sites (yellow), CGS Geotechnical Array sites (green), UCSB sites (red), SCEC/PBO sites (blue), AnzaNet Shallow Borehole sites (orange) shown.