Geoscience Reference
In-Depth Information
BOX 3.5
Example of a Message from a Tsunami Warning Center
WC/ATWC Information Statement - TW
WEAK53 PAAQ 270857
TIBAK1
PUBLIC TSUNAMI INFORMATION STATEMENT NUMBER 3 NWS WEST COAST/ALASKA TSUNAMI
WARNING CENTER PALMER AK
1257 AM PST SAT FEB 27 2010
...A STRONG EARTHQUAKE HAS OCCURRED BUT A TSUNAMI IS NOT
EXPECTED ALONG THE CALIFORNIA/ OREGON/ WASHINGTON/
BRITISH COLUMBIA OR ALASKA COASTS...
NO WARNING... NO WATCH AND NO ADVISORY IS IN EFFECT FOR THESE AREAS.
A TSUNAMI HAS BEEN GENERATED THAT COULD POTENTIALLY IMPACT THE U.S. WEST COAST/
BRITISH COLUMBIA AND ALASKA.
THE WEST COAST/ALASKA TSUNAMI WARNING CENTER IS INVESTIGATING THE EVENT
TO DETERMINE THE LEVEL OF DANGER. MORE INFORMATION WILL BE ISSUED AS IT BECOMES
AVAILABLE.
A TSUNAMI HAS BEEN OBSERVED AT THE FOLLOWING SITES
to issue evacuation orders based on the messages released by the TWCs. Given the separation in
responsibilities and authorities, close coordination between the TWCs, states, and local juris-
dictions is needed to ensure that the public receives information about the threat and proper
protective action (see the section on interagency coordination for more discussion). Observa-
tions during the 2010 Chilean event suggest that confusion still exists among the public about
actions to take in response to the TWC messages (Wilson et al., 2010). Initial observations of the
warning messages issued related to the 2010 Chilean earthquake and tsunami suggest that
California jurisdictions did not have a consistent understanding of lines of communication, what
an “advisory” alert level means in terms of recommended next steps, or who should be involved
in taking next steps (Wilson et al., 2010).
The committee also found inconsistencies between the warning products of the TWCs and
those of the NWS. For example, the NWS issues a “watch” for an event that has an 80 percent
chance of becoming a warning, but this is not the case with the TWCs whose watches rarely
