Uplift of the Crater Bottom of the Sarychev Peak Volcano (Matua Island, Kurils) in 2017–2019 Inferred from Satellite Images As a Precursor of an Upcoming Strong Eruption

The lava plug in the crater of the Sarychev Peak volcano (Kuril Islands) was removed in June 2009 as a result of explosions that accompanied a strong eruption, and the crater-bottom elevation abruptly decreased thereafter. Based on satellite imagery and images taken during a helicopter overflight in 2016, the level of crater-bottom sinking was measured at about 190–220 m from the crater rim. The crater bottom had been stable up until autumn 2017, when it began to rise, as revealed from the satellite imagery. As of autumn 2019, the crater bottom has been uplifted by approximately 150 m. The crater volume filled during this rising is about 10 million m 3 . The cycles of subsidence and rising in the last 75 years were repeated three times with respect to every strong (considerable) eruption. The new period of rising probably indicates the preparation for a new, potentially dangerous eruptive event.