At Sheveluch, in the Kamchatka peninsula, the explosive-extrusive eruption continues.
On April 27, the KVERT reports an ash plume at 4,400 meters asl., drifting southeast over a hundred km.
On April 28, a Sentinel 2 image, taken during clearings, allows to see the hot spots of the summit area and the flows.
The aviation code remains orange, ash explosions can occur at any time.
Sources: KVERT & Sentinel 2
In Costa Rica, three volcanoes are on alert level 3 / eruption, steady state: Rincon de la Vieja, Turrialba and Poas.
In Poas, inacandescence is observed in the early hours of April 28th; during the morning, a white degassing (majority of steam) continues.
At Merapi, Java, the BPPTKG reports a pyroclastic flow on April 28 at 10:00, for more than two minutes, not observed directly because of the haze.
Seven blast earthquakes and 44 earthquakes of collapses are reported at the PVMBG for the same day.
The activity level remains at 2 / waspada, with a prohibited area of 3 km radius.
Sources: BPPTKG, Magma Indonesia & PVMBG
Some quieter news:
In New Zealand, the period of high temperature that marked the Te Wai crater lake of Ruapehu, as well as the associated volcanic tremor, has passed. During the past week, small plumes of steam have been observed; we can expect a gradual cooling as winter approaches.
The volcanic alert is at level 1, minor instability ... an eruption is likely to occur without or with little warning.
In Japan, Sakurajima remains calm for the moment.
Some photos of my friend Pierre Gondolff, on the spot, attest of the situation.
The Sakurajima remains on alert level 2 / do not approach the volcano, established on February 5, 2016 by the JMA
Sources: PierreGondolff, whom I thank for sharing photos, and JMA