Written by Glen Mattioli
16 April 2019
Continuous GPS (and now GNSS) networks capture our Earth’s surface deformation at time scales from seconds to weeks and months. This deformation is associated with plate motion, strain accumulation along plate boundaries, earthquakes, volcanic unrest, and the earth’s response to changes in water availability. UNAVCO was awarded operations of the NSF Geodetic Facility for the Advancement of Geoscience (GAGE) starting in October 2018. As a critical component of GAGE, UNAVCO has integrated and federated pre-existing, NSF-funded continuous GPS/GNSS-meteorological networks into a single pan-American network. The newly designated Network of the Americas (NOTA) incorporates three major networks: the EarthScope Plate Boundary Observatory (PBO), 1,100 stations spanning Alaska, the continental US, and Puerto Rico; TLALOCNet, 40 stations in Mexico; and COCONet, 85 stations spanning the Caribbean. This hemispherical-scale, distributed resource will support a wide range of scientific applications and stakeholders.
NOTA is comprised of ~1,257 continuous GPS/GNSS and 270 surface meteorological stations. UNAVCO intends to maintain as many of these stations as feasible within the budget constraints over the 5-year period of this new GAGE Facility (2018-2023). Additionally, the GAGE Facility will support 1) Continued modernization of NOTA, as resources permit, to high-rate (>1 Hz), low-latency (<1 s), well-hardened sites to support research activities related to transient phenomena such as earthquakes and volcanic unrest and eruption, and loading from hydrospheric events, such as flooding and storm surge from hurricanes; and 2) Upgrading of ~1/4 of existing NOTA GPS stations to full multi-constellation GNSS capabilities.
Other NOTA station enhancements will include the integration of GNSS and seismic systems to support research and development in hazard monitoring and earthquake early warning. In particular, when coupled with real-time-GNSS-capable sites, low-cost micro-electro-mechanical systems (MEMS) accelerometers will greatly enhance real-time risk mitigation during large earthquakes (>M7) and volcanic eruptions (>VEI6).
One of the most exciting opportunities afforded by NOTA is the potential to use the network as an expandable platform on which ancillary scientific instrumentation can be added to further scientific goals of the global geodetic community (Figure 2). Currently, 270 stations have co-located surface meteorological instruments (145 PBO, all 40 TLALOCNet , and all 85 COCONet Core). Together, GNSS data and metpacks constrain column-integrated precipitable water vapor. This measurement enhances hurricane forecasting and flood warnings.
Last modified: 2020-01-28 22:54:06 America/Denver