Spatial Distribution of Landslides vis-à-vis Epicentral Distribution of Earthquakes in the Vicinity of the Main Central Thrust zone, Uttarakhand Himalaya, India

Abstract

Landslides and related mass movement activities along with earthquakes are common in the Himalayan terrain. The distribution of seismic activities in the vicinity of the Main Central Thrust (MCT) is well known. However, in order to assess the relationship between these seismic events and landslides, the spatial distribution of landslides and earthquake events (magnitude >1.5) on either side of the MCT zone was evaluated. It has been observed that seismic events of magnitude <2.1 are clustered around the 1991 Uttarkashi earthquake rupture, 1999 Chamoli earthquake rupture and around Munsiyari. The zone surrounding 1999 Chamoli earthquake rupture indicates the highest earthquake and landslide density of ~75% and 53% respectively.