SCEC Award Number 18140 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title SCEC Borehole Instrumentation Program
Investigator(s)
Name Organization
Jamison Steidl University of California, Santa Barbara
Other Participants Ethan Wang
Sam Bell
SCEC Priorities 4a, 1d, 3a SCEC Groups Seismology, GM, EEII
Report Due Date 03/15/2019 Date Report Submitted 07/07/2019
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. The past two years, the program has been “in-between” funding from a large major sponsor, and currently the leverage is spread out across multiple agencies/organizations (PG&E, SCEC, USGS, UCSB) at a significantly lower cost to each. Some of the organizations the SCEC borehole instrumentation program continues to work with include Caltech/USGS, ANSS/NSMP, the California Geological Survey, the UC San Diego HPWREN program, the NSF GAGE PBO program at UNAVCO, and the 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 com-bined 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 nonlin-earity. These stations are helping GMPE modelers to understand the component of uncertainty in ground motion predic-tion that is related to the site effect.
Broader Impacts Undergraduate and graduate students have always been, and continue to be used in the borehole 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 are getting 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.