Plate Boundary Observatory
The Plate Boundary Observatory (PBO) was the geodetic component of the
PBO precisely measured Earth deformation resulting from the constant motion of the Pacific and North American tectonic plates in the western United States. These Earth movements can be very small and incremental and not felt by people, or they can be very large and sudden, such as those that occur during earthquakes and volcanic eruptions. The high-precision instrumentation of the PBO enabled detection of motions to a sub-centimeter level. PBO measured Earth deformation through a network of instrumentation including: high-precision Global Positioning System (GPS) and Global Navigation Satellite System (GNSS) receivers, strainmeters, seismometers, tiltmeters, and other geodetic instruments.
The PBO GPS network included 1100 stations extending from the Aleutian Islands south to Baja and eastward across the continental United States. During the construction phase, 891 permanent and continuously operating GPS stations were installed, and another 209 existing stations were integrated (PBO Nucleus stations) into the network. Geodetic imaging data was transmitted, often in realtime, from a wide network of
The GPS stations were categorized into clusters. The transform cluster was near the
Data from the PBO was, and NOTA data continue to be, transmitted to the GAGE Facility, operated by EarthScope Consortium, to the data center where it is collected, archived and distributed. These data sets continue to be freely and openly available to the public, with equal access provided for all users. PBO data includes the raw data collected from each instrument, quality-checked data in formats commonly used by PBO's various user communities, and processed data such as calibrated time series, velocity fields, and error estimates.
Some scientific questions that addressed by the EarthScope project and the PBO data include:[3]
- How does accumulated strain lead to earthquakes?
- Are there recognizable precursors to earthquakes?
- How does the evolution of the continent influence the motions that are happening today?
- What happens to geologicstructures at depth?
- What influences the location of features such as mountain ranges?
- Is it inherited from earlier tectonic events or related to deeper processes in the mantle?
- How is magma generated? How does it travel from the mantle to reach the surface?
- What are the precursors to a volcanic eruption?[4]
References
- ^ "EarthScope". EarthScope.
- ^ UNAVCO (2009). Plate Boundary Observatory: The first five years. p. 10.
- ^ Williams, M.L., K.M. Fische r, J.T. Freymuelle r, B. Tikoff, A.M. T réhu; et al. (February 2010). Unlocking the Secrets of the North American Continent: An EarthScope Science Plan for 2010-2020 (PDF). p. 78. Archived from the original (PDF) on 14 April 2015. Retrieved 9 April 2015.
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: CS1 maint: multiple names: authors list (link) - ^ National Research Council, Review of EarthScope Integrated Science (Washington D.C., National Academy Press, 2001).