U.S. West Coast, Alaska, and British Columbia coastal regions
NOAA/NWS/West Coast and Alaska
Tsunami Warning Center
Tsunami Watch and Advisory
#3 issued 03/11/2011 at 12:26AM PST
The magnitude is updated and water level observations have been
The Tsunami Advisory
continues in effect for the coastal areas of Alaska from Chignik Bay, Alaska to Attu, Alaska.
The Tsunami Watch
continues in effect for the coastal areas of California, Oregon, Washington, British Columbia and Alaska from the California-Mexico border to Chignik Bay, Alaska.
A Tsunami Advisory means that a tsunami capable of
producing strong currents or waves dangerous to persons in or very near
the water is expected. Significant, widespread inundation
is not expected for areas
under an advisory. Currents may be hazardous to swimmers, boats,
and coastal structures and may continue for several hours after the
initial wave arrival.
A Tsunami Watch means that all coastal residents in the
should prepare for possible evacuation. A tsunami watch is issued
to areas which will not be immediately impacted by the tsunami.
Watch areas will either be upgraded to warning or advisory status,
At 9:46 PM Pacific Standard Time on March 10, an
preliminary magnitude 8.9
occurred near the east coast of Honshu, Japan
(Refer to the United States Geological Survey for official earthquake parameters.)
This earthquake has generated a tsunami which could
cause damage to coastal regions in a warning or advisory.
The waves are expected to first reach
Shemya, Alaska at 12:13 AM AKST on March 11.
Estimated tsunami arrival times
along with safety rules
and other information
can be found on the WCATWC
Measurements or reports of tsunami activity:
Location Lat. Lon. Time Amplitude
Time - Time of measurement.
------------------------ ----- ------ ------- -----------
Tosashimizu Japan 32.8N 132.9E 0747UTC 00.9FT/00.27M
Tokai Japan 33.8N 137.6E 0645UTC 00.8FT/00.25M
Ofunato Japan 39.0N 141.8E 0605UTC 10.8FT/03.29M
Hanasaki Japan 43.3N 145.6E 0643UTC 09.3FT/02.82M
Boso Japan 34.8N 140.8E 0609UTC 02.6FT/00.78M
Amp. - Tsunami amplitudes are measured relative to normal sea
level. It is NOT crest-to-trough wave height.
Values are given in both meters (M) and feet (FT).
can be dangerous waves that are not survivable. Wave heights are
amplified by irregular shoreline and are difficult to forecast.
Tsunamis often appear as a strong surge and may be preceded by a
receding water level. Mariners in water deeper than 600 feet should
not be affected by a tsunami. Wave heights will increase rapidly as
water shallows. Tsunamis are a series of ocean waves which can be
dangerous for several hours after the initial wave arrival. DO NOT
return to evacuated areas until an all clear is given by local civil
Pacific coastal regions outside California, Oregon, Washington,
British Columbia, and Alaska should refer to the
Pacific Tsunami Warning Center
messages for information on the event.
This message will be updated in 30 minutes or sooner if
the situation warrants. The tsunami message will remain
in effect until further notice. For further information stay tuned
to NOAA Weather Radio, your local TV or radio stations, or see
the WCATWC web site.
Link to Standard Warning Message
Link to Public Warning Message
Link to XML/CAP Message
Link to Printable Message