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  4. Deploying Technology for Distributed Use of Global Navigation Satellite System Products in Earthquake and Tsunami Warning

Deploying Technology for Distributed Use of Global Navigation Satellite System Products in Earthquake and Tsunami Warning

Rapid modeling of the earthquake source is critical to earthquake and tsunami early warning systems, in particular for mitigating hazards to near-source coastal communities. Operational earthquake early warning and rapid response in the U.S. is the role of the U.S. Geological Survey, and for tsunamis, the National Oceanic and Atmospheric Administration (NOAA) through its Tsunami Warning Centers. Traditionally, monitoring of earthquakes and tsunamis has been based on seismic networks for rapidly estimating earthquake magnitude and slip, and tide gauges and deep-ocean buoys for measurement of tsunami waves offshore. Since the under-estimation of the size of the 2011 Mw 9.0 Tohoku-Oki, Japan, earthquake and the resulting under-prediction of tsunami inundation in the presence of the most extensively instrumented warning system in the world, it has become clear that additional observations are necessary to mitigate a future repeat of the massive destruction as a consequence of large subduction zone earthquakes. Replay of the recorded data from Tohoku and other large subduction zone events has definitively demonstrated that now-time analysis of high-rate GPS, and more generally Global Navigation Satellite Systems (GNSS), observations for station displacements provides rapid magnitude estimates and direct fault displacement measurements that remove any ambiguity about the maximum size of the earthquake. It provides direct inputs to tsunami generation models, especially critical for the most vulnerable populations and infrastructure nearest the earthquake source. The integration of GNSS with other data types, i.e., seismogeodesy (the combination of GNSS and strong-motion accelerometers), near-shore GNSS buoys and ocean-bottom pressure sensors has proven to further increase warning accuracy.

This proposal leverages more than a decade of research funded by NASA and NSF at the Scripps Institution of Oceanography’s Orbit and Permanent Array Center (SOPAC) and other research groups in developing prototype geodetic-enhanced earthquake and tsunami early warning systems. Based on our development of algorithms for each of the required functions, we will implement plug-in modules for real-time access to and management of GNSS data, estimation of displacement and velocity waveforms using precise point positioning technology, rapid determination of earthquake source properties, sea floor uplift parameters, and tsunami extent and inundation using seamless interfaces to a user’s other in-house Earth observations and models. Specifically, we will collaborate with NOAA TWCs to integrate now-time GNSS-based observations and models into their operational systems. Collaboration with NOAA on tsunami warning in the Indo-Pacific Rim is a key NASA objective and falls within the Earth Surface and Interior science focus area “How can our knowledge of Earth surface change be used to predictand mitigate natural hazards?”

The primary objective of our proposal is seamlessly enabling GNSS into NOAA TWC operations with the following Java and C based plug-ins:

  1. (1) GNSS real-time data streaming in parallel with other data types.
  2. (2) GNSS PPP with ambiguity resolution with the option to optimally integrate collocated accelerometer data.
  3. (3) Near-source real-time earthquake detection and rapid magnitude estimation.
  4. (4) Earthquake fault parameter estimation as input to sea floor uplift models.
  5. (5) Tsunami prediction methodology based on heterogeneous data. Considering the maturity of SIO’s system, the project will begin at TRL 7 and end at TRL 8 after two years. The links with the respective agencies have already been established through the Real-Time Earthquake Analysis for Disaster mItigation network (READI) working group and requests for these capabilities have originated within NOAA. Therefore, we expect that the operations concept will be supported beyond the two-year Advancing Collaborative Connections for Earth System Science (ACCESS) funding and become operational at NOAA (TRL 9).
Yehuda Bock, University of California San Diego

Last Updated: Nov 15, 2017 at 3:38 PM EST