NASA System Detects Two Tsunami Energies In The Palu Event

October 7, 2018

NASA System Detects Two Tsunami Energies In The Palu Event

 

Figure 1: Tele-seismic data

Fig. 1: Tele-seismic data used in real-event calculation, black denotes observations and red means synthetic values.

Figure 2: Potential Energy and Kinetic Energy

Fig. 2: Two tsunami source energies were derived: Potential Energy (PE) due to seafloor uplift and Kinetic Energy (KE) due to horizontal seafloor displacement.

Figure 3: Strike-slip earthquake

Figure 3: How could strike-slip earthquake generate tsunamis? Most strike-slip earthquakes don’t generate damaging tsunamis if no seafloor-slope involved (Fig. 3(a)-(b)).  However this Palu earthquake was different. In addition to the commonly known tsunami energy caused by the vertical uplift of seafloor (Fig. 3(c)), the seafloor slope off the Gulf of Palu slipped into the ocean (Fig. 2), created kinetic energy to the ocean (Fig. 3(d)), which magnified the tsunami.

 

NASA and NOAA are collaborating to develop a Global Navigation Satellite System (GNSS) based tsunami early-detection system. GNSS based tsunami early-detection systems allow for rapid and more accurate tsunami warnings. Some of the technology components from NASA/NOAA's GNSS based tsunami early-detection system prototype have been transferred to NOAA’s Tsunami Warning Centers for testing. The prototype system was running at NASA’s Jet Propulsion Laboratory (JPL) during the Palu, Indonesia event. Results were generated from the prototype system within 14 minutes after the earthquake, and forwarded to Tsunami Warning Centers. Previously, earthquake magnitude has been the key parameter for tsunami early warning. In some cases, earthquake magnitude often does not scale the resulting tsunami, like the Palu event. The new NASA/NOAA system uses both GNSS and seismic data to detect tsunami energy scale for early warning. In the future, systems like these will provide rapid tsunami warnings and therefore save lives.