The PBO borehole seismometer network

During of the installation of the Plate Boundary Observatory, UNAVCO installed 79 borehole seismometers from Vancouver Island to Southern California, including Yellowstone. 74 are co-located with borehole strainmeters and five are stand alone installations. The sensors installed are Sonde-2 seismometers. This sensor uses three 2 HZ geophones in a triaxial configuration. Eight sites in the Anza, CA region also have MEMS accelerometers. The data set generated by this network has become an integral component to research being done in regional seismic networks, such as those in Anza, CA and Yellowstone NP. The depth of installation allows for the detection and location of microseisms that can be missed by a surface installation. To improve the data quality of the network UNAVCO is calibrating and orientating the seismometers in the PBO network. Local and regional earthquakes are used in conjunction with a co-located surface seismometer for the orientation process. A birddog is utilized to determine the instrument response for the individual geophones in the seismic package.