The Plate Boundary Observatory Borehole Network: Combining Geodetic, Seismic and Environmental Data to Understand Plate Boundary Deformation Abstract

abstract

  • The Plate Boundary Observatory (PBO), the geodetic component of the NSF-funded Earthscope program, is designed to capture the continuous three-dimensional deformation field across the western US plate boundary. Installed and maintained by UNAVCO, the observatory currently consists of over 1100 continuously operating GPS stations and 79 borehole installations. PBO boreholes are multi-instrumented sites containing a combination of strainmeters, seismometers, pore pressure sensors, tiltmeters, barometric pressure sensors, and rainfall and temperature sensors. Measurements include 100-sps seismic data, 20-sps strain, 1-sps pore, barometric and tilt data plus low frequency rainfall and temperature measurements. The sites are built in targeted arrays with spacing between boreholes ranging from a few hundred meters to several kilometers. Combining the different geophysical measurements over this range of sample rates and instrument spacing improves both the temporal and spatial resolution of tectonic signals, creating a rich data set that can yield better understanding of the tectonic processes involved in plate boundary deformation. In this presentation we will highlight some of the unique signals recorded by the borehole network in the past 12 months, including the evolution of strain transients associated with the summer 2010 Cascadia Episodic Tremor and Slip event, recordings of tsunamis-generated strain signals as they arrived along the North American coastline and aseismic slip events along the creeping section of the San Andreas in Parkfield. Between 50 and 60 separate channels of data are collected from most of the PBO boreholes. The majority of the data are made available to the scientific community within one to two hours of download, the exception being the seismic data, which are available in near-real time. Providing the scientific community with an easily-accessible, rapidly available data set plus all the associated metadata presents challenges of its own. We will outline how PBO monitors data quality for several data streams and data products available to the scientific community via the PBO web page (http://pboweb.unavco.org/), the Northern California Earthquake Data Center and the IRIS DMC .

publication date

  • 2010

presented at event