An Assessment of the Influence of Earthquake Duration in Inducing Landslides

Abstract

Earthquake duration is a complex natural phenomenon associated with the sudden energy release induced by fault rupture. The shaking during an earthquake is a result of the primary, secondary and surface waves. This study is aimed at establishing the relationship between earthquake duration and other seismic parameters: magnitude, peak ground acceleration, focal distance, fault length in relation to landslides generated by the major earthquakes. To achieve this objective, we made an intensive review of published data on major earthquakes (Mw ≥ 6.6) that generated landslides between 1998 and 2015 in the world. The results reveal that magnitude, focal length and focal depth times fault length are strong determinants of earthquake duration. However, it is noted that peak ground acceleration (PGA) and focal depth do not necessarily determine the duration of earthquake shaking. It is also observed that duration of an earthquake is moderately correlated to area affected by earthquake induced landslides. Additionally, much as the number of landslides produced during and/or after an earthquake does not necessarily augment with increasing duration majority of the investigated major earthquakes that produced great damage, with respect to landslides, were noticed to have lasted for not more than 60 seconds.