UPDATE: Volcanic activity observed at Veniaminof, Semisopochnoi
The U.S. Geological Survey says activity at Semisopochnoi volcano is continuing, with two explosions detected Wednesday morning from seismic and infrasound data.
USGS says the first explosion occurred just before 4 a.m. and another at around 10 a.m. Wednesday.
Ash clouds weren't observed at the time, but photos from two KTUU viewers showed ash clouds from two different vantage points.
Meanwhile, Mount Veniaminof, located on the Alaska Peninsula, is reportedly continuing to spew lava from the cone in the ice-filled summit caldera, according to USGS.
Veniaminof was captured erupting by KTUU viewer Joe Timmreck during a flight between Anchorage and Sand Point in September.
USGS says low-level activity is also being observed at Cleveland and Great Sitkin volcanoes, with elevated surface temperatures observed at Cleveland and seismic activity above background levels at Great Sitkin.
Strong seismic activity consistent with a volcanic eruption was measured by the U.S. Geological Survey on Semisopochnoi Island beginning at 8:47 p.m. Thursday night, with a small ash cloud observed by satellite at an altitude of 12,000 feet at 9:00 p.m. Thursday.
USGS has raised the Aviation Color Code and Alert Level to Orange for the volcano on Semisopochnoi or Unyak Island, located in the western Aleutian Islands at an elevation of 2,625 feet.
Southeast winds were reported in the area.
The seismic activity is reportedly diminishing.