Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Pacific Tsunami Warning Center (PTWC) is one of two tsunami warning centers that are operated by NOAA in the United States. Headquartered in Ewa Beach, Hawaii, the PTWC is part of an international tsunami warning system (TWS) program and serves as the operational center for TWS of the Pacific issuing bulletins and warnings to participating members and other nations in the Pacific Ocean area of responsibility . It is also the regional (local) warning center for the State of Hawai''i. The other tsunami warning center is the West Coast and Alaska Tsunami Warning Center (WCATWC) in Palmer, Alaska, serving all coastal regions of Canada and the United States except Hawai''i.