• GPS-Aided and DART-Ensured Real-time(GADER) Tsunami Early Detection System
Program Disasters Program
PI / Institution Y. Tony Song / Jet Propulsion Laboratory
Start Date October 1, 2012
End Date September 30, 2013
  • Summary

    Early tsunami warning critically hinges on rapid analysis of the triggering earthquake, but unfortunately, even precise knowledge of the earthquakes location and magnitude is not enough to predict a tsunamis power (scale) that is needed for effective early warnings. Recently, we have demonstrated the use of coastal Global Positioning System (GPS) stations to infer the seafloor displacements due to large earthquakes and from these displacements successfully determine a tsunamis power (scale) for issuing warnings before the tsunami reaches coastal areas [Song 2007]. This innovative method has been successfully tested in a NASA pilot programthe GPS-aided Real-Time Earthquake and Tsunami (GREAT) Alert System, during the events of the 2010 Chilean M8.8 earthquake and the 2011 Japanese M9.0 earthquake and associated tsunamis. We propose an important but practical enhancement to the existing GPS-aided alert system by augmenting it with the National Oceanic and Atmospheric Administrations (NOAA) Deep-ocean Assessment and Reporting of Tsunami (DART) system for a real-time tsunami detection and verification system. The DART system consists of an anchored seafloor bottom pressure recorder and a companion moored surface buoy for real-time communication, and measuring tsunami height at the anchored location (http://www.ndbc.noaa.gov/dart.shtml/). The GPS-Aided and DART-Ensured Real-time (GADER) tsunami detection system will: ""Improve near-field early warnings and save lives. Note that most of the tsunami victims are local. Our GPS data is used to estimate seafloor displacements, aiming to predict tsunami scales immediately following the earthquake, and before the tsunami reaches shore, enabling an early alert to local communities. ""Reduce false alarms and increase reliability. To avoid possible bias from the land-based GPS measurements of the earthquake, nearby ocean-based DART measurements of tsunami height will be assimilated into the system based on the recently proposed all-source Greens function (ASGF) method [Xu and Song 2011] to verify the GPS-aided alert scale. The combination of these two existing real-time systems offers the best solution for early detection and early cancelation. To demonstrate the feasibility of the combined system we will perform the following two tasks: 1.Assimilate the DART array data into and refine the GREAT alert system to automatically verify the GPS-based tsunami prediction and ensure the alert scales; and 2.Demonstrate the feasibility and reliability of the combined automation system in selected historical events and scenario tests. The Stage 1-Feasibility study will be carried out in collaboration with Dr. Eddie Bernard, a tsunami expert and former director of NOAAs Pacific Marine Environmental Laboratory (PMEL), who implemented the DART system. This is a low risk, innovative and practical project that aims to mitigate one of the most catastrophic natural disasters. It strongly aligns with the NASA Applied Sciences Programs priority objectives to improve disaster forecasting, response, and mitigation by using data from two mature real-time operational systems: NASAs Global Differential GPS (GDGPS) System, and NOAAs DART system. Significant national and global societal benefits will follow from enhancing the existing disaster alert and management systems.