Geoscience Reference
In-Depth Information
COMPREHENSIVE RISK ASSESSMENT
Tsunami risk assessment is fundamental to the nation's tsunami programs, because it can
help support and guide risk reduction efforts, including tsunami education, preparedness plan-
ning, and warning system development. In particular, it can help allocate resources according
to greatest risk and thus ensure that efforts are prioritized to protect the most people. The
following three examples illustrate the beneits of such an assessment:
•
Priorities among states
. A comprehensive tsunami risk assessment could improve
resource allocations among states, territories, and commonwealths. In 2006, the Gov-
ernment Accountability Ofice (GAO) observed that “with the likely expansion of the
NTHMP from 5 state participants to potentially 28 state and territorial participants in
2006, it will be dificult for NOAA to ensure that the most threatened states receive the
resources they need to continue and to complete key mitigation activities without an
updated, risk-based strategic plan” (Government Accountability Ofice, 2006). To this
date, NTHMP resources are being allocated on the basis of estimated hazards, without
regard for vulnerability (National Tsunami Hazard Mitigation Program, 2009a).
•
Priorities among program elements
. A comprehensive tsunami risk assessment coupled
with cost-beneit analyses could also help NOAA weigh the value of warning and
forecasting on the one hand against that of education and community preparedness
on the other. The GAO's 2006 report noted that
NOAA's initial strengthening efforts emphasize detection and warning for
distant tsunamis, while the greater risk to most locations in the United States—
according to NOAA data as well as the National Science and Technology
Council's (NSTC) December 2005 report on tsunami risk reduction—[is] likely
to be posed by local tsunamis. For example, the deployment of Deep-ocean
Assessment and Reporting of Tsunamis (DART) stations and warning center en-
hancements will not reduce the local tsunami risk as directly as other strategies
such as educating vulnerable populations to immediately head for high ground
when the earth shakes near the coast (Government Accountability Ofice, 2006).
•
Program development
. Understanding tsunami risk helps averts surprises. In the 1980s,
the Cascadia subduction zone became known as a source of catastrophic tsunamis,
irst from geophysical clues that it might produce such waves and then through geo-
logical signs that it had (Atwater et al., 2005). These discoveries about the tsunami haz-
ard were the irst indication of the need for Washington, Oregon, and California to take
steps to prepare to build tsunami-resilient communities before the next great Casca-
dia tsunami strikes. These discoveries also helped create the NTHMP itself. When the
NTHMP originated in the mid-1990s, it was founded in part on then-recent discoveries
about tsunami risk. Oregon's concern about Cascadia tsunami hazards played a central
role in the NTHMP's establishment, according to committee members' interviews with
founding members of the NTHMP steering group.
