Geoscience Reference
In-Depth Information
These efforts were originally part of the National Geodetic Survey, which developed the two
tsunami warning centers (TWCs) in Hawaii and Alaska after the 1946 Aleutian tsunami (Unimak
Island, AK) and the 1964 Alaskan tsunami (Prince William Sound, AK) (Figure 1.2). These centers
eventually became part of NOAA's National Weather Service (NWS), but each is located in differ-
ent NWS regions and is managed independently.
Concern about tsunamis in Washington, Oregon, and California increased in the late 1980s
and early 1990s when several new scientiic studies revealed their near-ield tsunami threat
from the Cascadia subduction zone (Atwater, 1987; Heaton and Hartzell, 1987). California was
reminded of its potential tsunami threat by an earthquake near Cape Mendocino in 1992,
which generated a small tsunami that arrived in Eureka only minutes after the earthquake
occurred. These and other developments prompted a more urgent call to produce comprehen-
sive assessments of tsunami risk and preparedness at the state and federal level.
Congress responded to this call in a 1995 Senate Appropriations Committee request to
NOAA to develop a plan for reducing tsunami risk to coastal communities. NOAA suggested
the formation of a national committee to address tsunami threat, leading to the establishment
of the NTHMP that same year. The NTHMP is tasked with coordinating the various federal, state,
territorial, and commonwealth tsunami efforts. NOAA's Tsunami Program was established in
2005 to incorporate all the current tsunami efforts at NOAA (see below). To respond to the
committee's charge (see Appendix B) and assess progress made toward improved tsunami
warning and preparedness, the committee begins its evaluation with an inventory of the ele-
ments of the NTHMP and NOAA's Tsunami Program.
National Tsunami Hazard Mitigation Program
The NTHMP has a Coordinating Committee (steering committee) that works to collabo-
rate on the tsunami mitigation efforts of the NTHMP and three subcommittees: a Mapping
and Modeling Subcommittee, a Warning Coordination Subcommittee, and a Mitigation and
Education Subcommittee.
3
In addition to coordinating individual efforts, the NTHMP provides
guidance to NOAA's TWSs. Federal partners include NOAA, the U.S. Geological Survey (USGS),
and the Federal Emergency Management Agency (FEMA). State partners originally included
Hawaii, Alaska, Washington, Oregon, and California, and now include all 29 U.S. coastal states
and territories.
The USGS contributes to the seismic network that the TWCs use through operating and
maintaining their respective seismic networks and to the tsunami research and risk assess-
ments and conducts an independent seismic analysis of potential tsunamigenic earthquakes
at its National Earthquake Information Center (NEIC). The USGS and NOAA both support the
Global Seismographic Network (GSN), which provides high-quality seismic data to assist earth-
quake detection (including tsunamigenic earthquakes). Both agencies also support earthquake
and seismic studies to improve tsunami warning efforts and tsunami disaster response and
hazards assessments. FEMA is responsible for hazard mitigation and emergency response; as
3
nthmp.tsunami.gov.
