On Friday 11 March 2011 at 2:46pm local time, an 8.9 magnitude earthquake struck close to the north east coast of Japan approximately 250 miles from Tokyo with a depth of up to 15 metres. The quake triggered a huge tsunami which swept inland near the city of Sendai in Miyagi.
Fast Facts: - This is the largest earthquake on records to have hit Japan - Confirmed death toll Is 15,890 as of February 10, 2015. -Material damage from the earthquake and tsunami is estimated at about 25 trillion yen ($300 billion). - The Japanese government estimates that the tsunami swept about five million tons of debris offshore, but that 70 percent sank, leaving 1.5 million tons floating in the Pacific Ocean. Tsunami Forecast Model:
The map below shows the Pacific Tsunami Warning Center's "tsunami forecast model" of wave heights above normal sea level across the region and how long after the 0546 GMT earthquake they were expected. |
Future Prediction:
When the powerful earthquake of 11 March triggered a tsunami that struck swathes of Japan's north-east coast, residents, TV crews and fixed cameras captured images of the devastating wave. Footage of the debris-filled water sweeping across fields and through houses has since been broadcast all over the world. But as well as providing an idea of how it felt to experience the tragedy first-hand, experts say the images can now be used to better understand the characteristics of tsunamis and help save lives in the future. As an earthquake strikes, early models of tsunamis are produced by millions of calculations and vast amounts of data-gathering which attempt to accurately predict the size and path of the wave. Much of this data is collected by tsunamographs, instruments that lie up to 5,000 metres below the water's surface, measuring changes in water pressure and transmitting information to nearby buoys. The buoys then send this data, via satellite, back to warning centres. "As the wave keeps on propagating across the Pacific, more and more tsunamograph recordings become available, so the forecast improves," - Dr Synolakis. from the University of Southern California and the Hellenic Centre for Marine Research in Greece However, even with these increasingly sophisticated techniques, there are still surprises. Often, due to inconsistencies in the sea bed and other natural variations, a tsunami can take a dramatically different course. Even with better equipped building defences, some natural disasters will always cause devastation. |