National Tsunami Warning Center, NOAA/NWS

TSUNAMIS of 20 August, 2011 (Vanuatu)

A major earthquake with a moment magnitude of 7.1 (USGS magnitude) occurred at 16:55:02 UTC 20 August 2011 (day 232) and was located 39 miles/63 km SSW of Port-Vila, Efate, Vanuatu (18.260S, 168.069E, 25.2 mi/40.6 km depth--USGS location).

A second major earthquake with a moment magnitude of 7.0 (USGS magnitude) occurred at 18:19:02 UTC 20 August 2011 (day 232) and was located 42 miles/69 km SSW of Port-Vila, Efate, Vanuatu (18.287S, 168.132E, 17.7 mi/28.5 km depth--USGS location).

These earthquakes produced two tsunamis that were recorded at tide gages monitored by the National Tsunami Warning Center (NTWC). Many observatories provide data to the 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 wave arrival computed at the NTWC based on the earthquake origin time and location. The Sample Interval column shows the time between data samples.

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

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