Author(s)

Nils-Axel Mörner

Paleogeophysics & Geodynamics, Stockholm, Sweden.

There is a fairly strict relation between maximum tsunami wave heights and causation earthquake magnitudes. This provides a new tool for estimating the magnitude of past earthquakes from the observed wave heights of related paleo-tsunami events. The method is subjected to a test versus two paleoseismic events with multiple independent estimates of corresponding earthquake magnitude. The agreement to the tsunami wave height conversion is good, confirming very high magnitudes of M 8.5 - 9.0 and M 8.4 - 8.5. Applying the same method to two Late Holocene events of methane venting tectonics indicates a ground shaking of forces equivalent to a M 8.0 earthquake, seriously changing previous long-term crustal hazard assessments.

Tsunamis, Wave Height, Earthquakes, Magnitudes, Paleo-Tsunamis, Methane Venting Tectonics, Hazard Assessment

Mörner, N. (2017) Converting Tsunami Wave Heights to Earthquake Magnitudes. Open Journal of Earthquake Research, 6, 89-97. doi: 10.4236/ojer.2017.62005.