Magnitude
7.3
Date-Time
Friday, December 07, 2012 at 08:18:24 UTC
Friday, December 07, 2012 at 06:18:24 PM at epicenter
Thursday, December 06, 2012 at 10:18:24 Hawaii Standard Time
Location
37.889°N, 144.090°E
Depth
36.1 km (22.4 miles)
Region
OFF THE EAST COAST OF HONSHU, JAPAN
Distances
284 km (176 miles) E (97°) from Sendai, Honshu, Japan
296 km (184 miles) ENE (71°) from Iwaki, Honshu, Japan
319 km (198 miles) E (86°) from Fukushima, Honshu, Japan
459 km (285 miles) NE (56°) from TOKYO, Japan

TSUNAMI BULLETIN NUMBER 001
PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS
ISSUED AT 0825Z 07 DEC 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 -  0818Z 07 DEC 2012
 COORDINATES -  37.7 NORTH  144.6 EAST
 DEPTH       -   33 KM
 LOCATION    -  OFF THE EAST COAST OF HONSHU  JAPAN
 MAGNITUDE   -  7.3

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.

Japan Tsunami Warning/Advisory info: 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.