A Decade of Great Earthquakes
US NWS Pacific Tsunami Warning Center (PTWC), 5 December 2014.

December 2014 includes the 10-year anniversary of the 9.1 magnitude Sumatra-Andaman earthquake that generated the 2004 Indian Ocean Tsunami, one of the worst disasters in history with a death toll exceeding 200,000 people. In the decade following this event there have been many more tsunamis triggered by great earthquakes, and this animation shows all earthquakes in sequence at a speed of 30 days per second from 1 December 2004 to 30 November 2014, concluding with a map showing all earthquakes recorded in this span of time. It then transitions to a map showing just those earthquakes with magnitude 6.5 or greater (about 500 total), the smallest size known to generate a dangerous tsunami and thus the threshold PTWC typically uses to begin assessing tsunami risk. It then transitions one more time to a map showing earthquakes with magnitude 8.0 or greater (17 total), the "great" earthquakes that are most likely to pose a tsunami hazard if they occur near the sea floor.

Top image: YouTube screen capture.

[Source: US NWS Pacific Tsunami Warning Center. Top image added.]

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