Magnitude
6.8
Date-Time
Wednesday, March 14, 2012 at 09:08:37 UTC
Wednesday, March 14, 2012 at 07:08:37 PM at epicenter
Tuesday, March 13, 2012 at 11:08:37 PM HST
Location
40.899°N, 144.923°E
Depth
26.6 km (16.5 miles)
Region
OFF THE EAST COAST OF HONSHU, JAPAN
Distances
235 km (146 miles) S of Kushiro, Hokkaido, Japan
265 km (164 miles) SSE of Obihiro, Hokkaido, Japan
293 km (182 miles) E of Hachinohe, Honshu, Japan
734 km (456 miles) NE of TOKYO, Japan

TSUNAMI BULLETIN NUMBER 001
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 0917Z 14 MAR 2012

THIS BULLETIN APPLIES TO AREAS WITHIN AND BORDERING THE PACIFIC
OCEAN AND ADJACENT SEAS…EXCEPT ALASKA…BRITISH COLUMBIA…
WASHINGTON…OREGON AND CALIFORNIA.

… TSUNAMI INFORMATION BULLETIN …

THIS BULLETIN IS FOR INFORMATION ONLY.

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 REPORTED BY THE JAPAN METEOROLOGICAL AGENCY.

ORIGIN TIME – 0908Z 14 MAR 2012
COORDINATES – 40.7 NORTH 145.2 EAST
DEPTH – 10 KM
LOCATION – OFF EAST COAST OF HONSHU JAPAN
MAGNITUDE – 6.8

EVALUATION

NO DESTRUCTIVE WIDESPREAD TSUNAMI THREAT EXISTS BASED ON HISTORICAL EARTHQUAKE AND TSUNAMI DATA.

HOWEVER – EARTHQUAKES OF THIS SIZE SOMETIMES GENERATE LOCAL TSUNAMIS THAT CAN BE DESTRUCTIVE ALONG COASTS LOCATED WITHIN A HUNDRED KILOMETERS OF THE EARTHQUAKE EPICENTER. AUTHORITIES IN THE REGION OF THE EPICENTER SHOULD BE AWARE OF THIS POSSIBILITY AND TAKE APPROPRIATE ACTION.

THIS WILL BE THE ONLY BULLETIN ISSUED FOR THIS EVENT UNLESS ADDITIONAL INFORMATION BECOMES AVAILABLE.

THE JAPAN METEOROLOGICAL AGENCY MAY ALSO ISSUE TSUNAMI MESSAGES FOR THIS EVENT TO COUNTRIES IN THE NORTHWEST PACIFIC AND SOUTH CHINA SEA REGION. IN CASE OF CONFLICTING INFORMATION… THE MORE CONSERVATIVE INFORMATION SHOULD BE USED FOR SAFETY.

THE WEST COAST/ALASKA TSUNAMI WARNING CENTER WILL ISSUE PRODUCTS FOR ALASKA…BRITISH COLUMBIA…WASHINGTON…OREGON…CALIFORNIA.

Only slight sea level changes of 0.2m or less were recorded in Japan.

Japan Meteorological Agency Tsunami Warning/Advisory

Issued at 19:40 JST 14 Mar 2012

Tsunami Warnings and/or Advisories have been cancelled.

*******************Text********************
Tsunami Advisories have been cancelled for the following coastal regions of Japan:
EASTERN PART OF PACIFIC COAST OF HOKKAIDO
CENTRAL PART OF PACIFIC COAST OF HOKKAIDO
PACIFIC COAST OF AOMORI PREF.
IWATE PREF.
The above-mentioned Tsunami Warnings/Advisories have been cancelled.
Pay attention when fishing, swimming or engaging in other activities, as there may be still slight sea-level changes for the time being.

*******Tsunami Warning/Advisory now in effect********
No Tsunami Warnings and Advisories are currently in effect.

For more information visit the Japan Meteorological Agency – http://www.jma.go.jp/en/tsunami/index.html

USGS: How large does an earthquake have to be to cause a tsunami?

Magnitudes below 6.5
Earthquakes of this magnitude are very unlikely to trigger a tsunami.

Magnitudes between 6.5 and 7.5
Earthquakes of this size do not usually produce destructive tsunamis. However, small sea level changes may be observed in the vicinity of the epicenter. Tsunamis capable of producing damage or casualties are rare in this magnitude range but have occurred due to secondary effects such as landslides or submarine slumps.

Magnitudes between 7.6 and 7.8
Earthquakes of this size may produce destructive tsunamis especially near the epicenter; at greater distances small sea level changes may be observed. Tsunamis capable of producing damage at great distances are rare in the magnitude range.

Magnitude 7.9 and greater
Destructive local tsunamis are possible near the epicenter, and significant sea level changes and damage may occur in a broader region.

Note that with a magnitude 9.0 earthquake, the probability of an aftershock with a magnitude exceeding 7.5 is not negligible. To date, the largest aftershock recorded has been magnitude 7.1 that did not produce a damaging tsunami.