Updated: 12/30 at 10:30 a.m.
Eruptions at a volcano in the Eastern Aleutian Islands are thought to have begun earlier than previously thought.
According to a retrospective analysis, the Alaska Volcano Observatory now thinks Bogoslof volcano first erupted on December 16.
So far, the observatory believes there have been eight eruptions this month and there could be more. Previous eruptions have lasted weeks.
The eruptions have lasted as long as an hour, thrown ash up to 35,000 ft into the air, and dramatically changed the island.