Operational users guide for the Pacific Tsunami Warning and Mitigation System (PTWS)

Technical series no. 87:

This guide’s primary purpose is to provide a summary of the operational procedures of the Centers*, an overview of the seismic and sea level monitoring networks used by the Centers, the criteria for issuing tsunami messages, and the methods by which messages are sent.

The Guide is intended for use by the responsible agencies within each country of the PTWS who are recipients of tsunami messages from the international Centres.

Section 1 provides the objectives and purposes of the Guide. Section 2 describes the administrative procedures, the organizations involved, and how to subscribe to services offered. Section 3 provides an overview of the three operational Centers, while Sections 4-6 describe in detail the services each of them provide. Annexes provide additional background on tsunamis, earthquake source characterizations, message interpretation and emergency response, sea level measurements, travel time calculations and wave forecasting.

*The Centers are the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Pacific Tsunami Warning Center (PTWC), the NOAA West Coast / Alaska Tsunami Warning Center (WC/ATWC) and the Japan Meteorological Agency’s (JMA) Northwest Pacific Tsunami Advisory Center (NWPTAC).