Using Global Navigation Systems for Early Tsunami Warning about Tsunamis Excited by Magnitude 7–8 Earthquakes

Abstract

Rapid and reliable tsunami forecasting for regions close to the epicenter of an undersea earthquake remains an unsolved problem. The only method of rapid tsunami hazard estimation used in Russia is the magnitude criterion. It leads to an unacceptably high percentage of false alarms. One promising new method is the modeling of the earthquake source based on the coseismic displacements recorded at coastal observation sites by Global Navigation Satellite Systems (GNSS). In this paper, we focus on the possibility of using this method for the magnitude 7–8 intraplate earthquakes, for which it is necessary to determine the rupture plane orientation. Based on numerical experiments, we obtained estimates of the accuracy and reliability of the earthquake parameters depending on the magnitude, number and relative positions of GNSS stations. We show that it is possible to determine all the main parameters of the source model of an M ≥ 7.4 earthquake based on the GNSS data, although the accuracy would not be very good. We conclude that it is advisable to use GNSS data in tsunami warning systems, at first in the testing mode.