Hekla in the distance. (Photo: Hansueli Krapf/CC BY-SA 2.0)

For years, Hekla, a volcano in southern Iceland, was active, erupting regularly—and sometimes with great force—over the past century. But it hasn’t been heard from since a small eruption in 2000, when it spewed ash for nearly two weeks. 

An Icelandic geophysicist said recently, though, that he thinks Hekla is getting ready to erupt again, according to the Iceland Monitor.

“Hekla is a dangerous volcano,” Páll Einarsson, a professor at the University of Iceland, told the news website Vísir. “We could be looking at a major disaster when the next eruption begins if we are not careful.”

The volcano, located in the southern part of the country, is also a popular site for hikers, but Einarsson thinks it could blow any minute. Pressure indicators on the volcano, he says, are higher than they’ve been before the last two eruptions, in 2000 and 1991. 

Hekla is around 70 miles to the east of the capital Reykjavik, where over a third of the country’s population live. One of Hekla’s biggest eruptions occurred in the Middle Ages, when, in 1104, an eruption is said to have covered at least half the island in ash and tephra. 

But while an eruption of that force may not be in the offing, it also probably isn’t a good time for a hike up Hekla.