A satellite image showing the volcanic cloud from Bogoslof's January 5, 2017 eruption.
© Dave Schneider, AVO/USGS

A satellite image showing the volcanic cloud from Bogoslof's January 5, 2017 eruption.
Two hours after lowering the aviation code for an Eastern Aleutian volcano, it's back at the highest alert level.

The reasoning? According to the Alaska Volcano Observatory, there was a significant explosion at Bogoslof volcano Thursday afternoon.

The observatory detected a raised level of seismicity around 1:30 p.m. as well as reports from the World Wide Lightning Detection Network of lightning strikes. A pilot reported seeing a volcanic cloud at 35,000 ft.

The volcano has been erupting since mid-December.