Alaska's Pavlof Volcano erupts

Pavlof volcano, which is one of the most active on the Alaska peninsula, began erupting this past weekend according to earthsky.com. The volcano spewed ash as high as 20,000 feet over the weekend and as high as 37,000 feet on Monday, March 28.

Jessica Larsen of the University of Alaska's Geophysical Institute told British Columbia's CBC News that the eruption has been unexpected. She told them:

"Pavlof is known to us for having a pretty quick onset to eruptions. It doesn't always give us long precursory signals.

"If you look at some of the seismic data that we have, the intensity really ramped up pretty fast. It was quite abrupt.

Above: Pavlof volcano in eruption, 3 am, March 28, 2016. Taken by Royce Snapp from Cold Bay, AK, with a 500 mm lens. Cold Bay is 36 miles southwest of Pavlof. (Source: Alaska Volcano Observatory)

The following is the update that the USGS released on Monday:

Lightning associated with the ash eruption has been detected this morning, and infra-sound (pressure sensor) data from a sensor network located in Dillingham (400 miles or 650 km) also indicate sustained ash emissions.

As of 7:00 Alaska Daylight Time (15:00 UTC), a continuous plume of ash is observed in satellite images extending for a distance of more than 400 miles (650 km) to the northeast over interior Alaska.

SIGMET warning messages issued by the National Weather Service Alaska Aviation Weather Unit indicate maximum ash cloud altitude of 37,000 feet above sea level.

The USGS said the eruption appeared to be declining as of Tuesday morning.