Why and how do tsunami earthquakes occur

Knowledge pool
Japan - earthquake, tsunami, nuclear disaster

  • Tokyo Sky Tree will be the tallest television tower in the world at 634 meters. Since in Japan mostly digital television is broadcast via antenna, the Sky Tree will also be the most important transmission mast for future earthquake warnings from the state broadcaster NHK.

The Tohoku – Oki quake surprised the experts with its unexpected enormous strength and an extensive fracture zone of at least 250 kilometers. The submarine faults of the Pacific Plate north of Tokyo were considered to be well explored until 2011 and not as a candidate for the great catastrophe.

With the event in 2011, the conception of the course of mega-earthquakes also fundamentally changed. Everywhere in countries at the edge of the plate, studies are commissioned in the following years to determine the risk of so-called megathrust quakes, i.e. large quakes in the thrust area of ​​plates. After March 11, 2011, seismologists discovered that many findings about the course of mega tremors had turned out to be wrong. The amount of energy generated by the quake has also been underestimated so far.

For many years, major quakes were expected in Japan, especially south of Tokyo. In areas quite close to the coast between Tokyo and Osaka, along the Philippine plate boundary, Tokai, Tonankei and Nankei (between Tokyo and Osaka), the quake was expected, which would cause severe devastation in Tokyo.

Here, too, the quake of 2011 forced a rethink, a new beginning in terms of earthquake expectations. The motto for research and government is now: Prepare for the surprising, the unexpected. Virtually every location in Japan is at risk of earthquakes, and there are no high or low risk levels for any particular region.