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000
WEPA40 PHEB 190403
TSUPAC

TSUNAMI MESSAGE NUMBER 4
NWS PACIFIC TSUNAMI WARNING CENTER HONOLULU HI
0400 UTC FRI MAY 19 2023

...PTWC TSUNAMI THREAT MESSAGE...


**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

 THIS MESSAGE IS ISSUED FOR INFORMATION ONLY IN SUPPORT OF THE
 UNESCO/IOC PACIFIC TSUNAMI WARNING AND MITIGATION SYSTEM AND IS
 MEANT FOR NATIONAL AUTHORITIES IN EACH COUNTRY OF THAT SYSTEM.

 NATIONAL AUTHORITIES WILL DETERMINE THE APPROPRIATE LEVEL OF
 ALERT FOR EACH COUNTRY AND MAY ISSUE ADDITIONAL OR MORE REFINED
 INFORMATION.

**** NOTICE **** NOTICE **** NOTICE **** NOTICE **** NOTICE *****

THE TSUNAMI FORECAST IS UPDATED IN THIS MESSAGE.

NOTE EARTHQUAKE MAGNITUDE WAS LOWERED TO 7.7 FROM 7.8.

PRELIMINARY EARTHQUAKE PARAMETERS
---------------------------------

  * MAGNITUDE      7.7
  * ORIGIN TIME    0257 UTC MAY 19 2023
  * COORDINATES    23.2 SOUTH  170.7 EAST
  * DEPTH          10 KM / 6 MILES
  * LOCATION       SOUTHEAST OF LOYALTY ISLANDS


EVALUATION
----------

  * AN EARTHQUAKE WITH A PRELIMINARY MAGNITUDE OF 7.7 OCCURRED
    SOUTHEAST OF THE LOYALTY ISLANDS AT 0257 UTC ON FRIDAY MAY
    19 2023.

  * TSUNAMI WAVES HAVE BEEN OBSERVED.

  * BASED ON ALL AVAILABLE DATA... HAZARDOUS TSUNAMI WAVES ARE
    FORECAST FOR SOME COASTS.


TSUNAMI THREAT FORECAST...UPDATED
---------------------------------

  * TSUNAMI WAVES REACHING 0.3 TO 1 METERS ABOVE THE TIDE LEVEL
    ARE POSSIBLE FOR SOME COASTS OF

      VANUATU.


  * TSUNAMI WAVES ARE FORECAST TO BE LESS THAN 0.3 METERS ABOVE
    THE TIDE LEVEL FOR THE COASTS OF

      AMERICAN SAMOA... AUSTRALIA... CHUUK... COOK ISLANDS...
      FIJI... FRENCH POLYNESIA... HOWLAND AND BAKER... JARVIS
      ISLAND... KERMADEC ISLANDS... KIRIBATI... KOSRAE...
      MARSHALL ISLANDS... NAURU... NEW ZEALAND... NIUE...
      PALMYRA ISLAND... PAPUA NEW GUINEA... POHNPEI... SAMOA...
      SOLOMON ISLANDS... TOKELAU... TONGA... TUVALU...
      WALLIS AND FUTUNA... AND NEW CALEDONIA.


  * ACTUAL AMPLITUDES AT THE COAST MAY VARY FROM FORECAST
    AMPLITUDES DUE TO UNCERTAINTIES IN THE FORECAST AND LOCAL
    FEATURES. IN PARTICULAR MAXIMUM TSUNAMI AMPLITUDES ON ATOLLS
    AND AT LOCATIONS WITH FRINGING OR BARRIER REEFS WILL LIKELY
    BE MUCH SMALLER THAN THE FORECAST INDICATES.

  * FOR OTHER AREAS COVERED BY THIS PRODUCT A FORECAST HAS NOT
    YET BEEN COMPUTED. THE FORECAST WILL BE EXPANDED IF
    NECESSARY IN SUBSEQUENT PRODUCTS.


RECOMMENDED ACTIONS
-------------------

  * GOVERNMENT AGENCIES RESPONSIBLE FOR THREATENED COASTAL AREAS
    SHOULD TAKE ACTION TO INFORM AND INSTRUCT ANY COASTAL
    POPULATIONS AT RISK IN ACCORDANCE WITH THEIR OWN
    EVALUATION... PROCEDURES AND THE LEVEL OF THREAT.

  * PERSONS LOCATED IN THREATENED COASTAL AREAS SHOULD STAY ALERT
    FOR INFORMATION AND FOLLOW INSTRUCTIONS FROM NATIONAL AND
    LOCAL AUTHORITIES.


ESTIMATED TIMES OF ARRIVAL
--------------------------

  * ESTIMATED TIMES OF ARRIVAL -ETA- OF THE INITIAL TSUNAMI WAVE
    FOR PLACES WITHIN THREATENED REGIONS ARE GIVEN BELOW. ACTUAL
    ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE
    LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN
    WAVES CAN BE FIVE MINUTES TO ONE HOUR.

    LOCATION         REGION             COORDINATES    ETA(UTC)
    ------------------------------------------------------------
    ANATOM ISLAND    VANUATU           20.2S 169.9E   0331 05/19
    ESPERITU SANTO   VANUATU           15.1S 167.3E   0431 05/19


POTENTIAL IMPACTS
-----------------

  * A TSUNAMI IS A SERIES OF WAVES. THE TIME BETWEEN WAVE CRESTS
    CAN VARY FROM 5 MINUTES TO AN HOUR. THE HAZARD MAY PERSIST
    FOR MANY HOURS OR LONGER AFTER THE INITIAL WAVE.

  * IMPACTS CAN VARY SIGNIFICANTLY FROM ONE SECTION OF COAST TO
    THE NEXT DUE TO LOCAL BATHYMETRY AND THE SHAPE AND ELEVATION
    OF THE SHORELINE.

  * IMPACTS CAN ALSO VARY DEPENDING UPON THE STATE OF THE TIDE AT
    THE TIME OF THE MAXIMUM TSUNAMI WAVES.

  * PERSONS CAUGHT IN THE WATER OF A TSUNAMI MAY DROWN... BE
    CRUSHED BY DEBRIS IN THE WATER... OR BE SWEPT OUT TO SEA.


TSUNAMI OBSERVATIONS
--------------------

  * THE FOLLOWING ARE TSUNAMI WAVE OBSERVATIONS FROM COASTAL
    AND/OR DEEP-OCEAN SEA LEVEL GAUGES AT THE INDICATED
    LOCATIONS. THE MAXIMUM TSUNAMI HEIGHT IS MEASURED WITH
    RESPECT TO THE NORMAL TIDE LEVEL.

                            GAUGE      TIME OF   MAXIMUM     WAVE
                         COORDINATES   MEASURE   TSUNAMI   PERIOD
    GAUGE LOCATION        LAT   LON     (UTC)     HEIGHT    (MIN)
    -------------------------------------------------------------
    LIFOU NEW CALEDONIA  20.9S 167.3E    0340   0.05M/ 0.2FT  10
    MARE NEW CALEDONIA   21.5S 167.9E    0342   0.08M/ 0.3FT  12


NEXT UPDATE AND ADDITIONAL INFORMATION
--------------------------------------

  * THE NEXT MESSAGE WILL BE ISSUED IN ONE HOUR... OR SOONER IF
    THE SITUATION WARRANTS.

  * AUTHORITATIVE INFORMATION ABOUT THE EARTHQUAKE FROM THE U.S.
    GEOLOGICAL SURVEY CAN BE FOUND ON THE INTERNET AT
    EARTHQUAKE.USGS.GOV.

  * FURTHER INFORMATION ABOUT THIS EVENT MAY BE FOUND AT
    WWW.TSUNAMI.GOV.

  * COASTAL REGIONS OF HAWAII... AMERICAN SAMOA... GUAM... AND
    CNMI SHOULD REFER TO PACIFIC TSUNAMI WARNING CENTER MESSAGES
    SPECIFICALLY FOR THOSE PLACES THAT CAN BE FOUND AT
    WWW.TSUNAMI.GOV.

  * COASTAL REGIONS OF CALIFORNIA... OREGON... WASHINGTON...
    BRITISH COLUMBIA AND ALASKA SHOULD ONLY REFER TO U.S.
    NATIONAL TSUNAMI WARNING CENTER MESSAGES THAT CAN BE FOUND
    AT WWW.TSUNAMI.GOV.

$$