The National Tsunami Warning Center (NTWC) is one of two tsunami warning centers in the United States, covering all coastal regions of the United States and Canada, except Hawaii, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands. Until 2013, it was known as the West Coast and Alaska Tsunami Warning Center.
The NTWC, operated by the National Oceanic and Atmospheric Administration (NOAA), detects and analyzes earthquakes worldwide, issuing warnings to local officials in the hazard zones about the advisability of evacuating low-lying coastal areas and moving ships to deep water.
The Pacific Tsunami Warning Center has the responsibility for areas of the U.S. which are not covered by NTWC.