ANI | Updated: Apr 09, 2021 19:44 IST New Delhi [India], April 9 (ANI): Scientists have found that the Himalayas are not uniform and assume different physical and mechanical properties in different directions - a property present in crystals called anisotropy which could result in significantly large earthquake events in the Himalayas. The northwestern region of India, an area covering Garhwal and Himachal Pradesh, has been hit by four destructive moderate to great earthquakes since the beginning of the 20th century -- the Kangra earthquake of 1905, the Kinnaur earthquake of 1975, the Uttarkashi earthquake of 1991, and the Chamoli earthquake of 1999. A Science and Technology Ministry release said that these seismic activities manifest large-scale subsurface deformation and weak zones, underlining the need for deeper insights into the ongoing deformation beneath these tectonically unstable zones.