The Indo–Eurasia convergent margin and earthquakes in and around Tibetan Plateau

Abstract

After a brief review on tectonic settings of the Himalayas and Tibetan Plateau, we survey the literature on characteristics of earthquakes occurring in Tibetan Plateau and the surrounding regions. Shallow events (focal depths <50 km) show remarkable correlation with surface fault systems in both spatial locations and focal mechanisms. Some shallow events appear to be triggered by remote earthquakes and seasonal variations of ground water storage, suggesting stress levels nearing critical threshold. Intermediate–depth earthquakes (IDEQs; i.e., earthquakes with focal depths between 50 and 300 km) are concentrated beneath southern Tibet, the Hindu Kush–Pamir region, and the Burmese subductions zones. Underneath southern Tibet, the subducted Indian plate extends northward to at least the Bangong–Nujiang suture zone, with IDEQs occurring in the lower crust and the adjacent upper mantle. Possible mechanisms for IDEQs are also reviewed.