Powerful earthquakes hit Indonesia

Indonesia was hit yesterday (Wednesday) by one great (M8.4) and one major (M7.9) earthquakes, followed by a number of strong to moderate aftershocks. News reports about the quakes can be found all over the web, but also here, here, here and here.

The various tsunami warning centers, including the Pacific Tsunami Warning Center in Hawaii, reacted immediately, sending out first preliminary warnings then tsunami reports. Mike Dunford wrote a nice post about these tsunami warnings here.

Here are the ShakeMaps (earthquake intensity maps) published by the USGS for these two earthquakes, followed by the most up-to-date tsunami bulletin by the PTWC for the larger of the two events (the PTWC has issued a warning also for the second event, available here):

TSUNAMI BULLETIN NUMBER 005
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 1505Z 12 SEP 2007

THIS BULLETIN IS FOR ALL AREAS OF THE INDIAN OCEAN.

... FINAL INDIAN-OCEAN-WIDE TSUNAMI WATCH ...

THIS THE FINAL TSUNAMI WATCH FOR

INDONESIA / AUSTRALIA / INDIA / SRI LANKA / THAILAND / UNITED KINGDOM / MALDIVES / MYANMAR / MALAYSIA / BANGLADESH / MAURITIUS / REUNION / SEYCHELLES / MADAGASCAR / SOMALIA / OMAN / PAKISTAN / IRAN / YEMEN / COMORES / CROZET ISLANDS / MOZAMBIQUE / KENYA / TANZANIA / 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 - 1110Z 12 SEP 2007
COORDINATES - 4.5 SOUTH 101.3 EAST
LOCATION - SOUTHERN SUMATERA INDONESIA
MAGNITUDE - 8.2

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION LAT LON TIME AMPL PER
------------------- ----- ------ ----- --------------- -----
SIBOLGA ID 1.7N 98.8E 1434Z 0.09M / 0.3FT 52MIN
PADANG ID 0.9S 100.4E 1348Z 0.98M / 3.2FT 34MIN
COCOS CC 12.1S 96.9E 1236Z 0.11M / 0.4FT 22MIN
DART 23401 8.9S 88.5E 1421Z 0.02M / 0.1FT 15MIN
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.

EVALUATION

SEA LEVEL READINGS INDICATE A TSUNAMI WAS GENERATED. IT MAY HAVE BEEN DESTRUCTIVE ALONG COASTS NEAR THE EARTHQUAKE EPICENTER.

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.

BASED ON AVAILABLE DATA THIS CENTER DOES NOT EXPECT MORE WIDESPREAD DESTRUCTIVE EFFECT. HOWEVER ... DUE TO ONLY LIMITED SEA LEVEL DATA FROM THE REGION IT MAY NOT BE POSSIBLE FOR THIS CENTER TO RAPIDLY NOR ACCURATELY EVALUATE THE STRENGTH OF A TSUNAMI IF ONE HAS BEEN GENERATED.

ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES AT FORECAST POINTS WITHIN THE WARNING AND WATCH AREAS 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 SUCCESSIVE WAVES CAN BE FIVE MINUTES TO ONE HOUR.

LOCATION FORECAST POINT COORDINATES ARRIVAL TIME
-------------------------------- ------------ ------------
INDONESIA BENGKULU 3.9S 102.0E 1123Z 12 SEP
SIBERUT 1.5S 98.7E 1203Z 12 SEP
PADANG 0.9S 100.1E 1214Z 12 SEP
BANDAR LAMPUNG 5.7S 105.3E 1242Z 12 SEP
SIMEULUE 2.5N 96.0E 1243Z 12 SEP
CILACAP 7.8S 108.9E 1307Z 12 SEP
BANDA ACEH 5.5N 95.1E 1329Z 12 SEP
BALI 8.7S 115.3E 1345Z 12 SEP
KUPANG 10.0S 123.4E 1453Z 12 SEP
BELAWAN 3.8N 99.0E 1703Z 12 SEP
AUSTRALIA CHRISTMAS IS 10.4S 105.4E 1220Z 12 SEP
COCOS ISLAND 12.1S 96.7E 1234Z 12 SEP
NORTH WEST CAPE 21.5S 113.9E 1429Z 12 SEP
CAPE INSPIRATIO 25.9S 113.0E 1526Z 12 SEP
CAPE LEVEQUE 16.1S 122.6E 1542Z 12 SEP
PERTH 32.0S 115.3E 1545Z 12 SEP
AUGUSTA 34.3S 114.7E 1559Z 12 SEP
GERALDTOWN 28.6S 114.3E 1603Z 12 SEP
ESPERANCE 34.0S 121.8E 1726Z 12 SEP
KINGSTON SOUTH 37.0S 139.4E 1906Z 12 SEP
EUCLA MOTEL 31.8S 128.9E 1934Z 12 SEP
DARWIN 12.1S 130.7E 1948Z 12 SEP
HEARD ISLAND 54.0S 73.5E 1955Z 12 SEP
HOBART 43.3S 147.6E 2015Z 12 SEP
INDIA GREAT NICOBAR 7.1N 93.6E 1338Z 12 SEP
LITTLE ANDAMAN 10.7N 92.3E 1421Z 12 SEP
PORT BLAIR 12.0N 92.5E 1440Z 12 SEP
NORTH ANDAMAN 13.3N 92.6E 1453Z 12 SEP
CHENNAI 13.4N 80.4E 1540Z 12 SEP
KAKINADA 17.2N 82.7E 1604Z 12 SEP
TRIVANDRUM 8.3N 76.9E 1608Z 12 SEP
BALESHWAR 21.6N 87.3E 1701Z 12 SEP
MANGALORE 13.3N 74.4E 1732Z 12 SEP
BOMBAY 18.8N 72.6E 2005Z 12 SEP
GULF OF KUTCH 22.7N 68.9E 2019Z 12 SEP
SRI LANKA DONDRA HEAD 5.8N 80.5E 1447Z 12 SEP
TRINCOMALEE 8.7N 81.3E 1502Z 12 SEP
COLOMBO 6.9N 79.8E 1515Z 12 SEP
JAFFNA 9.9N 80.0E 1625Z 12 SEP
THAILAND PHUKET 8.0N 98.2E 1508Z 12 SEP
KO PHRA THONG 9.1N 98.2E 1554Z 12 SEP
KO TARUTAO 6.6N 99.6E 1626Z 12 SEP
UNITED KINGDOM DIEGO GARCIA 7.3S 72.4E 1526Z 12 SEP
MALDIVES GAN 0.6S 73.2E 1528Z 12 SEP
MALE 4.2N 73.6E 1544Z 12 SEP
MINICOV 8.3N 73.0E 1614Z 12 SEP
MYANMAR PYINKAYAING 15.8N 94.2E 1537Z 12 SEP
CHEDUBA ISLAND 18.9N 93.4E 1554Z 12 SEP
SITTWE 20.0N 92.9E 1629Z 12 SEP
MERGUI 12.8N 98.4E 1647Z 12 SEP
YANGON 16.2N 96.5E 1713Z 12 SEP
MALAYSIA GEORGETOWN 5.4N 100.1E 1704Z 12 SEP
PORT DICKSON 2.5N 101.7E 2048Z 12 SEP
BANGLADESH CHITTAGONG 22.5N 91.2E 1801Z 12 SEP
MAURITIUS PORT LOUIS 20.0S 57.3E 1803Z 12 SEP
REUNION ST DENIS 20.8S 55.2E 1820Z 12 SEP
SEYCHELLES VICTORIA 4.5S 55.6E 1847Z 12 SEP
MADAGASCAR TOAMASINA 17.8S 49.8E 1900Z 12 SEP
ANTSIRANANA 12.1S 49.5E 1905Z 12 SEP
MANAKARA 22.2S 48.2E 1919Z 12 SEP
CAP STE MARIE 25.8S 45.2E 2009Z 12 SEP
MAHAJANGA 15.4S 46.2E 2009Z 12 SEP
TOLIARA 23.4S 43.6E 2034Z 12 SEP
SOMALIA HILALAYA 6.5N 49.2E 1922Z 12 SEP
CAPE GUARO 11.9N 51.4E 1933Z 12 SEP
MOGADISHU 2.0N 45.5E 1938Z 12 SEP
KAAMBOONI 1.5S 41.9E 2004Z 12 SEP
OMAN SALALAH 17.0N 54.2E 1930Z 12 SEP
DUQM 19.7N 57.8E 1939Z 12 SEP
MUSCAT 23.9N 58.6E 1943Z 12 SEP
PAKISTAN GWADAR 25.1N 62.4E 1937Z 12 SEP
KARACHI 24.7N 66.9E 2031Z 12 SEP
IRAN GAVATER 25.0N 61.3E 1943Z 12 SEP
YEMEN AL MUKALLA 14.5N 49.2E 2003Z 12 SEP
ADEN 13.0N 45.2E 2100Z 12 SEP
COMORES MORONI 11.6S 43.3E 2006Z 12 SEP
CROZET ISLANDS CROZET ISLANDS 46.4S 51.8E 2009Z 12 SEP
MOZAMBIQUE CABO DELGADO 10.7S 40.7E 2034Z 12 SEP
ANGOCHE 15.5S 40.8E 2044Z 12 SEP
QUELIMANE 18.0S 37.1E 2213Z 12 SEP
MAPUTO 25.9S 32.8E 2218Z 12 SEP
BEIRA 19.9S 35.1E 2246Z 12 SEP
KENYA MOMBASA 4.0S 39.7E 2039Z 12 SEP
TANZANIA LINDI 9.8S 39.9E 2039Z 12 SEP
DAR ES SALAAM 6.7S 39.4E 2047Z 12 SEP
KERGUELEN ISLAN PORT AUX FRANCA 49.0S 69.2E 2049Z 12 SEP
SOUTH AFRICA PRINCE EDWARD I 46.6S 37.6E 2146Z 12 SEP
DURBAN 29.8S 31.2E 2205Z 12 SEP
PORT ELIZABETH 33.9S 25.8E 2256Z 12 SEP
CAPE TOWN 34.1S 18.0E 2359Z 12 SEP
SINGAPORE SINGAPORE 1.2N 103.8E 0048Z 13 SEP

THE JAPAN METEOROLOGICAL AGENCY MAY ISSUE ADDITIONAL INFORMATION FOR THIS EVENT. IN THE CASE OF CONFLICTING INFORMATION...THE MORE CONSERVATIVE INFORMATION SHOULD BE USED FOR SAFETY.