Grishin S. Yu.
Proceedings of the Russian geographical society 2018; 150(6): 72-88
Assessments of the volcanic hazard for the territory of the Matua Island are based on incomplete data collected in a short observation period (less than 100 years), and therefore cannot reliably characterize the frequency and scale of hazardous events. In addition to the phenomena recorded during the strong eruption of the Sarychev Peak volcano in 2009 (and during a number of eruptions of the 20th century), which scale and range of impact on the nature of the island has not been sufficiently studied, new signs of potential hazards have been revealed. These are gas emissions that caused damage to woody vegetation in 2007, as well as data on the large-scale destruction of woody vegetation that occurred about 150 years ago. These can also include particularly high eruptive columns (the 2009 eruption). The high frequency of strong eruptions was revealed: during the last century and a half, 4 eruptions of the VEI 4 class occurred, not counting the smaller ones. During strong eruptions, a combination of unfavorable factors can develop suddenly and unpredictably, it will lead to devastating consequences in the south-eastern half of the island. In the aspect of the new colonization phase of the island, potential hazard may be represented by pyroclastic flows and surges on the southeastern slopes of the volcano, lahars, and the impact of strong gas emissions. A powerful ashfall can cause damage to ecosystems, including contaminating and poisoning accessible sources of water, damaging the infrastructure. The obtained data allow drawing a conclusion that in the next 30-50 years no part of the island can be considered safe.
