UNAVCO installed 891 permanent and continuously operating Global Positioning System (CGPS) stations and integrated 209 PBO Nucleus stations, which were previously part of legacy GPS networks.
Each GPS monument is deeply anchored to ensure high-quality measurements of station positions and velocities. CGPS stations are ideal for measuring volcanic and plate tectonic motions, strain accumulation on faults, earthquake surface displacement, and post-seismic deformation. These data provide constraints on fault zone behavior and the earthquake cycle on time scales of days to decades.
UNAVCO installed 74 borehole tensor strainmeters (BSM) and 78 short-period borehole seismometers as part of PBO. BSMs measure subtle shape changes of an instrument cemented into bedrock and are highly sensitive to ground deformation at periods of minutes to months, bridging the sensitivity and frequency gap between seismic and GPS measurements. Observations from UNAVCO's borehole seismometers provide low-noise seismic data at depth in remote regions, which have been key in distinguishing wind noise from tremor in the Yellowstone caldera.
The Plate Boundary Observatory installed five long-baseline laser strainmeters (LSM) and took over the operation and maintenance of a legacy station that was built to similar specifications. LSMs use a laser to measure the change in the relative position of end monuments hundreds of meters apart. These very stable and high-precision instruments measure strain change from months to decades and are an important tool for cross-validating long-term GPS measurements and monitoring stored energy near a major fault.
PBO operates a pool of 100 portable GPS systems for stand-alone temporary or semi-permanent deployments. These instruments support densification of observations around key tectonic targets and are used for rapid response to volcanic and tectonic events.
GeoEarthScope included the acquisition of airborne LiDAR imagery for the detailed mapping of Earth's surface, satellite InSAR imagery for the precise mapping of surface change during deformation events, and geochronology data to provide age constraints on prehistoric earthquakes and long-term fault offsets. Combined, these techniques allow the measurement of strain rates over broad time scales.
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National Aeronautics and |
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National |
Overview
2010