Shiveluch volcano in Russia. Image courtesy of KVERT.

Over this past weekend, Shiveluch in Kamchatka experienced a plinian eruption, producing a 7-km / 23,000 foot ash column. The NASA Terra satellite caught a great image of the ash plume over the snowy landscape of the Kamchatkan Peninsula on April 26, 2009. KVERT issued these comments on the current eruptive activity:
Seismic activity of the volcano slightly decreased but continues to remain at high levels. A continuous spasmodic volcanic tremor and series of weak shallow events continue to registering at volcano at present.

According to video data, moderate ash explosions continue to occur at
the lava dome of the volcano. Ash continuously appears from a big
fissure on the lava dome southern flank. Ash plumes extend to the
east-north-east from the volcano on the height about 4 km ASL.

These are typical eruptions from Shiveluch, with ash plumes from lava dome-extruding events. For updated information on Shiveluch's activity, check out the KVERT page for the volcano.