GPS Measurements at Vandenberg, AFB
Abstract
Recent geological and geodetic studies have suggested that the region surrounding Vandenberg AFB is undergoing active crustal deformation, with important implications for both the geodetic stability and the seismogenic potential of the Western Test Range (WTR) (Feigl et al., 1990. Part of the evidence for significant deformation was obtained from GPS measurements over a broad area of central and southern California, which we carried out in cooperation with other university and government scientists from 1987 through 1991. Although useful in defining the regional tectonic setting, these measurements are of insufficient spatial and temporal density to answer many important questions about the seismogenic potential of Vandenberg. The sites observed in the March 1992 survey are given in Table 1, and a map of the enlarged network is shown in Figure 1. Four new sites (CASM, FAARF, RDRK, and FIGP) were established on or bridging three of the four major anticlines that cut the Santa Maria Basin. Our primary scientific goal is to localize the measured deformation on one or more of these structures. One of the new sites (SOAP) provides a more stable anchor for that part of our network south of the Santa Ynez River Fault. Three other sites occupied for the first time (ARG3, VINA, VANP), as well as two previously occupied (ALVA, VNDN), are existing DMA sites near the south Base PGGA site (VNDP). This small sub-network provides a means to monitor the local stability of the three sites (VAND, VNDN, and VNDP) that have been or will be used for long-term monitoring of deformation. The two- day occupation of the South Base sub-network also provided us the opportunity to study more carefully the effects of atmospheric water vapor on GPS measurements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 22, 1993
- Accession Number
- ADA262280
Entities
People
- Robert King
Organizations
- Massachusetts Institute of Technology