Endogenic and Exogenic Hazardous Relief-Forming Processes on Sakhalin Island

Abstract Endogenous and exogenous relief-forming processes on Sakhalin Island are very dynamic. This can be due to both geological and tectonic (the position of the island on the border of tectonic plates, the predominance of easily destroyed rocks), and geographic factors (including the active interaction between oceanic and continental air masses and altitude). An active Central Sakhalin fault separating microplates provides primary control over seismicity and can have a noticeable effect on mud volcanism. The activity of a mud volcano, taking into account the impact on adjacent valleys, can affect up to 10 km2. The most common exogenous processes of the island are landslides, avalanches and mudflows. Up to 70% of Sakhalin’s territory is subject to these dangerous processes. They are also often triggered by seismic events. It is extremely difficult to predict the exact location and type of activated processes, as well as the time and frequency of their activation. The proposed map of tension in geomorphic systems makes it possible to conduct a reconnaissance assessment of the region, as well as a comparison between individual zones and determine the most dangerous ones.