Abstract:
West Coast/Alaska Tsunami Warning Center (WCATWC) response criteria for earthquakes
occurring in the Atlantic and Caribbean basins are presented. Initial warning center decisions are
based on an earthquake’s location, magnitude, depth, distance from coastal locations, and precomputed
threat estimates based on tsunami models computed from similar events. The new criteria
will help limit the geographical extent of warnings and advisories to threatened regions, and
complement the new operational tsunami product suite. Criteria are set for tsunamis generated by
earthquakes, which are by far the main cause of tsunami generation (either directly through sea floor
displacement or indirectly by triggering of sub-sea landslides).
The new criteria require development of a threat data base which sets warning or advisory zones
based on location, magnitude, and pre-computed tsunami models. The models determine coastal
tsunami amplitudes based on likely tsunami source parameters for a given event. Based on the
computed amplitude, warning and advisory zones are pre-set.
