Grímsvötn volcano, Iceland
Grímsvötn, a volcano located in southeast Iceland, is giving strong indications that an eruption may be coming in "the next weeks or months", a summary from the Icelandic Met Office reports. An atmospheric volcanologist The Grapevine spoke with says that if it does, it will probably be smaller than the eruption of 2011.

Dr. Melissa Anne Pfeffer, the atmospheric volcanologist in question, is part of a team of scientists who regularly study the activity of Iceland's volcanoes, Grímsvötn amongst them. She told The Grapevine that she had detected high levels of magmatic gasses which are usually not present when there is not an eruption happening. Furthermore, Grímsvötn is experiencing inflation, indicating an increase in magma.

As Grímsvötn's lake drains during the summer, this means less pressure on the volcano. Given the current conditions, when the flooding starts this summer, preparations for an eruption will begin. This may happen in the weeks or months to come.

That said, volcanoes are always mercurial phenomena and unpredictable. Glacial flooding does not necessarily lead to an eruption. If it does, though, Melissa says that scientists are expecting this eruption to be smaller than the one in 2011.

As to what kind of eruption it might be, this depends: if it erupts through the ice cap, then it will most likely be an ash eruption, but if the magma manages to make its way out away from the ice cap — as the eruption at Holuhraun did — than it could be a lava eruption.