How does PTWC evaluate earthquakes for tsunami potential?
First, we use seismic data to determine the earthquake hypocenter (location, depth) and magnitude. If the earthquake is underwater, less than 100 km in depth, and above a certain magnitude threshold, PTWC will issue the appropriate tsunami message (see About PTWC Messages). As more seismic data becomes available, PTWC can use more sophistocated methods to measure the earthquake’s slowness, which correlates with its tsunamigenic potential.
