Tsunami Warnings and Watches Issued for Alaska & West Coast

To: U.S. West Coast, Alaska, and British Columbia coastal regions
From: NOAA/NWS/West Coast and Alaska Tsunami Warning Center
Subject: Tsunami Watch and Advisory #3 issued 03/10/2011 at 11:33PM PST

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 watch area 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, or canceled.

At 9:46 PM Pacific Standard Time on March 10, an earthquake with preliminary magnitude 8.8 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 and maps along with safety rules and other information can be found on the WCATWC web site.

Hawaii Tsunami Warning update

000
WEHW40 PHEB 110731
TSUHWX
HIZ001>003-005>009-012>014-016>021-023>026-110931-
/O.CAN.PHEB.TS.A.0001.000000T0000Z-000000T0000Z/
/O.NEW.PHEB.TS.W.0001.110311T0731Z-000000T0000Z/
BULLETIN
TSUNAMI MESSAGE NUMBER   3
NWS PACIFIC TSUNAMI WARNING CENTER EWA BEACH HI
931 PM HST THU MAR 10 2011
TO - CIVIL DEFENSE IN THE STATE OF HAWAII
SUBJECT - TSUNAMI WARNING
A TSUNAMI WARNING IS ISSUED FOR THE STATE OF HAWAII EFFECTIVE AT
0931 PM HST.
AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS
   ORIGIN TIME - 0746 PM HST 10 MAR 2011
   COORDINATES - 38.2 NORTH  142.5 EAST
   LOCATION    - NEAR EAST COAST OF HONSHU  JAPAN
   MAGNITUDE   - 8.8  MOMENT
MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY
 GAUGE LOCATION        LAT   LON    TIME        AMPL         PER
 DART 21413           30.5N 152.1E  0659Z   0.76M /  2.5FT  32MIN
 HANASAKI HOKKAIDO J  43.3N 145.6E  0657Z   2.79M /  9.2FT  76MIN
 DART 21401           42.6N 152.6E  0643Z   0.67M /  2.2FT  40MIN
 DART 21418           38.7N 148.7E  0619Z   1.08M /  3.5FT  06MIN
 LAT  - LATITUDE (N-NORTH, S-SOUTH)
 LON  - LONGITUDE (E-EAST, W-WEST)
 TIME - TIME OF THE MEASUREMENT (Z IS UTC IS GREENWICH TIME)
 AMPL - TSUNAMI AMPLITUDE MEASURED RELATIVE TO NORMAL SEA LEVEL.
        IT IS ...NOT... CREST-TO-TROUGH WAVE HEIGHT.
        VALUES ARE GIVEN IN BOTH METERS(M) AND FEET(FT).
 PER  - PERIOD OF TIME IN MINUTES(MIN) FROM ONE WAVE TO THE NEXT.
 NOTE - DART MEASUREMENTS ARE FROM THE DEEP OCEAN AND THEY
        ARE GENERALLY MUCH SMALLER THAN WOULD BE COASTAL
         MEASUREMENTS AT SIMILAR LOCATIONS.
EVALUATION
 A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG
 COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION
 SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.
 A TSUNAMI IS A SERIES OF LONG OCEAN WAVES. EACH INDIVIDUAL WAVE
 CREST CAN LAST 5 TO 15 MINUTES OR MORE AND EXTENSIVELY FLOOD
 COASTAL AREAS. THE DANGER CAN CONTINUE FOR MANY HOURS AFTER THE
 INITIAL WAVE AS SUBSEQUENT WAVES ARRIVE. TSUNAMI WAVE HEIGHTS
 CANNOT BE PREDICTED AND THE FIRST WAVE MAY NOT BE THE LARGEST.
 TSUNAMI WAVES EFFICIENTLY WRAP AROUND ISLANDS. ALL SHORES ARE AT
 RISK NO MATTER WHICH DIRECTION THEY FACE. THE TROUGH OF A TSUNAMI
 WAVE MAY TEMPORARILY EXPOSE THE SEAFLOOR BUT THE AREA WILL
 QUICKLY FLOOD AGAIN. EXTREMELY STRONG AND UNUSUAL NEARSHORE
 CURRENTS CAN ACCOMPANY A TSUNAMI. DEBRIS PICKED UP AND CARRIED
 BY A TSUNAMI AMPLIFIES ITS DESTRUCTIVE POWER. SIMULTANEOUS HIGH
 TIDES OR HIGH SURF CAN SIGNIFICANTLY INCREASE THE TSUNAMI HAZARD.
 THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS
                     0259 AM HST FRI 11 MAR 2011
MESSAGES WILL BE ISSUED HOURLY OR SOONER AS CONDITIONS WARRANT.

http://www.weather.gov/ptwc/text.php?id=hawaii.2011.03.11.073148