POWERFUL AFTERSHOCK HITS WEST COAST OF NORTHERN SUMATRA

AKG SEISMOLOGY-

*** POWERFUL AFTERSHOCK HITS WEST COAST OF NORTHERN SUMATRA***
*** USGC REPORTS 8.2M***




A STRONG AFTERSHOCK HAS BEEN REPORTED AT 0.773°N, 92.452°E 


AT 10:43:09 UTC

AS OF NOW, TSUNAMI IS HEADING TOWARDS THE THAILAND COAST

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UPDATED INFORMATION FROM PACIFIC TSUNAMI WARNING CENTER IS INDICATING A STRONGER TSUNAMI WAVE THAN THE PREVIOUS HITING INDONESIA COAST

TSUNAMI BULLETIN NUMBER 004
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 1054Z 11 APR 2012

THIS BULLETIN IS FOR ALL AREAS OF THE INDIAN OCEAN.

... AN INDIAN-OCEAN-WIDE TSUNAMI WATCH IS IN EFFECT ...

... A MAJOR AFTERSHOCK OCCURRED AT 11:43Z WITH MAGNITUDE 8.3 ...

A TSUNAMI WATCH IS STILL IN EFFECT FOR

 INDONESIA / INDIA / AUSTRALIA / SRI LANKA / MYANMAR / THAILAND /
 MALDIVES / UNITED KINGDOM / MALAYSIA / MAURITIUS / REUNION /
 SEYCHELLES / OMAN / PAKISTAN / SOMALIA / MADAGASCAR / IRAN /
 UAE / YEMEN / COMORES / MOZAMBIQUE / KENYA / TANZANIA /
 CROZET ISLANDS / BANGLADESH / KERGUELEN ISLANDS / SOUTH AFRICA /
 SINGAPORE

THIS BULLETIN IS ISSUED AS ADVICE TO GOVERNMENT AGENCIES.  ONLY
NATIONAL AND LOCAL GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKE
DECISIONS REGARDING THE OFFICIAL STATE OF ALERT IN THEIR AREA AND
ANY ACTIONS TO BE TAKEN IN RESPONSE.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

 ORIGIN TIME -  0839Z 11 APR 2012
 COORDINATES -   2.3 NORTH   93.1 EAST
 LOCATION    -  OFF W COAST OF NORTHERN SUMATRA
 MAGNITUDE   -  8.7

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

 GAUGE LOCATION        LAT   LON    TIME        AMPL         PER
 -------------------  ----- ------  -----  ---------------  -----
 TELUKDALAM ID         0.6N  97.8E  0952Z   0.15M /  0.5FT  08MIN
 SABANG ID             5.8N  95.3E  1010Z   0.36M /  1.2FT  06MIN
 MEULABOH ID           4.1N  96.1E  1007Z   1.06M /  3.5FT  12MIN
 DART 23401            8.9N  88.5E  0956Z   0.03M /  0.1FT  06MIN
 SABANG ID             5.8N  95.3E  0956Z   0.31M /  1.0FT  08MIN

 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

 SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY
 ALREADY HAVE BEEN DESTRUCTIVE ALONG SOME COASTS.

 BASED ON THESE DATA THE THREAT CONTINUES FOR ALL COASTAL AREAS OF
 THE INDIAN OCEAN. FOR THOSE AREAS - WHEN NO MAJOR WAVES HAVE
 OCCURRED FOR AT LEAST TWO HOURS AFTER THE ESTIMATED ARRIVAL TIME
 OR DAMAGING WAVES HAVE NOT OCCURRED FOR AT LEAST TWO HOURS THEN
 LOCAL AUTHORITIES CAN ASSUME THE THREAT IS PASSED. DANGER TO
 BOATS AND COASTAL STRUCTURES CAN CONTINUE FOR SEVERAL HOURS DUE
 TO RAPID CURRENTS.  AS LOCAL CONDITIONS CAN CAUSE A WIDE
 VARIATION IN TSUNAMI WAVE ACTION THE ALL CLEAR DETERMINATION MUST
 BE MADE BY LOCAL AUTHORITIES.