Satellite images show a new caldera forming in the ice with a diameter of one kilometer (6/10ths of a mile) in Öræfajökull glacier.
Öræfajökull glacier is located in Vatnajökull, Iceland’s largest glacier.
Although seismic activity has subsided in recent days, activity had increased activity in recent months.
Öræfajökull volcano hasn’t erupted since 1727, and although the alert has been raised to yellow, the Met Office says there are no signs of an imminent eruption.
In addition to the siesmic activity, a great sulphuric stench emanated from the river Kvíá last week.
“(The smell) suggests that a hydrothermal systems have opened up somewhere under the glacier in Öræfajökull volcano,” says a post on Iceland Geology. “This means that magma has now reached depth of 1 km or less.”
According to Wikipedia, Öræfajökull is an ice-covered volcano in south-east Iceland at the southern end of the Vatnajökull glacier. It is the largest active volcano in the country.
Thanks to Laurel for this link
“The smelly river is a huge tipoff,” says Laurel. “Same happened prior to other kabooms;-)”