UPDATE: Aleutian Island Volcano Spews Ash 35,000 Feet Altitude, Prompting USGS to Issue “RED ALEART”

For the second straight day, the Alaska Volcano Observatory issued its highest alert level for aviation when a volcano erupted with a towering ash cloud in the Aleutian Islands.

Observatory volcanologist Robert McGimsey says yesterday afternoon’s eruption of the Bogoslof volcano was “almost a carbon copy” of an eruption 24 hours earlier. He says both eruptions prompted the highest alert level, “Red Alert” for Aviation and level “Warning” for Volcano Activity Notice, then hours later by one level.

The first eruption sent ash and steam 34,000 feet into the air, while the second burst went 1,000 feet higher. Officials say both volcanic explosions were also short-lived. The observatory said early Thursday that it was reducing the alert level because there had been no recent volcano activity. The volcano is on an island of the same name in the Bering Sea about 850 miles southwest of Anchorage.

Recent satellite imagery shows that this eruption dramatically changed Bogoslof Island, and that a new, small island has formed just offshore of the northeast end of the main island. The former shore and much of the northeast side of Bogoslof Island adjacent to this island has been largely removed, and deposition of material has occurred on the west side of the island. The excavated area of the former northeast shore is likely the vent for this recent eruption, which appears to be just below sea level.