National Tsunami Warning Center, NOAA/NWS

Tsunami of 21 December 2010 (Bonin Islands, Japan Region)

A Major earthquake with a moment magnitude of 7.4 (USGS magnitude) occurred at 17:19:40 UTC 21 December 2010 (day 355) and was located 95 miles/150 km E of Chichi-shima, Bonin Islands, Japan (26.892N, 143.726E, 8.7mi/14.0km depth--USGS location).

This earthquake produced a tsunami that was recorded at a number of tide gages operated by the Japan Meteorological Agency (JMA) as well as at DART buoys operated by the NOAA/NWS National Data Buoy Center (see the NDBC site for DART data). Many observatories provide data to the tsunami warning centers; such as the NOAA National Ocean Service, the U. of Hawaii Sea Level Center, the Chilean Navy, and the National Tidal Facility in Australia among others. Click on the site name to see a graph of the tsunami, when available. Listed wave heights are maximum amplitude in cm (above sea level). Observed Arrival time is the actual tsunami arrival time in UTC on gages where it could be determined. The Computed Arrival time is the estimated time of arrival computed at the National Tsunami Warning Center (NTWC) based on the origin time and location. The Sample Interval column shows the time between samples.

For additional information about this tsunami event see the Pacific Tsunami Warning Center's homepage.

 

travel time map

energy map

Travel Time Map
(click to enlarge)

Maximum Amplitude Graph
(click to enlarge)

 

Tide gage/
Measurement Location

Peak amplitude (above sea level in cm)

Observed Initial Arrival time
[UTC (J.Day)]

Estimated Arrival time (UTC)

Initial motion

Sample Interval (min)

Data File (Julian Day Starts at  0000 UTC)

Tosashimizu, Japan

13

1939 (355)

none

rise

1

355, 356

Hanasaki, Japan

7

2000 (355)

1943

?

1

355, 356

Ofunato, Japan

30

1918 (355)

1915

?

1

355, 356

Saipan, USA

8

1926 (355)

1908

?

1

355, 356

Arena Cove, CA

7

0351

?

1

356

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