I got datasets about Tsunami events.

According to International Tsunami Information Center and Indian Ocean UNESCO Tsunami center, for an earthquake to cause Tsunami it should have a large magnitude (> 6.5) and shallow focal depth ( < 100 km ).

But there are entries in NOAA tsunami dataset with focal depth of 260 km and a magnitude of 6.8 occurred at sea with the epicenter located at 21.1 km from the nearest coast. There are also entries with magnitude range of 4-5 causing tsunamis.

Are there some other characteristics of earthquake that may cause tsunami?


1 Answer 1


The rupture velocity of earthquakes is another factor that determines the magnitude of a tsunami. The term tsunami earthquakes was coined by Hiroo Kanamori in 1972 to describe when an earthquake having a slower rupture velocity (~1km/sec), compared to a more normal velocity (2.5-3.5 km/sec) of a typical earthquake, causes a tsunami greater in magnitude than expected.

This paper investigates the effect of a horizontal movement of sediments due to an 1896 earthquake that may have created a tsunami earthquake.

  • $\begingroup$ Is there any relatioship between magnitude, focal depth and rupture velocity of an earthquake so that we can compute rupture velocity by magnitude and focal depth. $\endgroup$ Dec 18, 2017 at 8:00
  • $\begingroup$ I'm not finding any definitive equation relating these parameters, but this paper from the Journal of Geophysical Research presents ways of estimating rupture velocity of large deep focus earthquakes. Maybe there is something within this that will help. $\endgroup$
    – user11318
    Dec 18, 2017 at 12:29

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