Fast Tsunami Predictions with the All-Source Green's Functions and the GPS-Aided Source Functions --- Illustrated by the 2011 Tohoku Tsunami

This paper proposes a new approach on how to predict tsunamis almost instantaneously when a submarine earthquake breaks out. The new approach is comprised of quick generation of a tsunami source and an instantaneous transfer of the source to a tsunami arrival time series at one or several points of interest. The seismic data and the coastal GPS-station displacements sensed by the satellites are all used to derive the tsunami source in real-time. The derived tsunami source consists of the initial sea surface elevations and the water depth averaged initial velocities. The instantaneous transfer of a source function to the arrivals at a point of interest is realized by an all-source Green's function (ASGF), which is pre-calculated for the destination point. The ASGF can operate on a source function originated anywhere in the oceans and allows the resolution of the source function as fine as the model's native resolution. The new approach is verified by the 2011 Tohoku tsunami data measured by the DART buoys.