Shiveluch volcano, Kamchatka: elevated activity, large explosive eruption on 6 Feb

A phase of intense activity has been taking place at the volcano over the past few days. On 6 Feb afternoon (or early morning 7 Feb in Kamchatka), a large eruption occurred. VAAC Tokyo spotted an ash plume drifting at approx. 27,000 ft (9 km) altitude more than 300 km northwest. The ash plume reached the Sea of Okhotsk and ash fall occurred in the village Sedanka at more than 200 km distance from the volcano.
Unfortunately, webcam images do not allow to determine whether this eruption had been caused by an explosion liberating accumulated pressure, or whether a major collapse of the actively growing viscous lava dome had taken place, producing pyroclastic flows and related co-ignimbrite ash plumes. It is possible if not likely that it was the result of a combination of both.