An 'Unusually Large' Ice Volcano in Iceland Had the Biggest Outbreak in More Than 300 Years Creating a Huge Hollow Lava Field

The volcano system of Bárðarbunga, which in 2014 produced Iceland's largest eruption in three centuries, is again showing some worrying signs of activity. On the morning of January 14, 2025, over 130 earthquakes struck the northwestern region of the volcano within five hours, with the strongest recorded at a magnitude of 5.1, according to the Icelandic Met Office. This seismic swarm is the biggest activity at the volcano since the last major eruption, which began in August 2014 and ended in February 2015. This latter created the Holuhraun lava field, as big as Manhattan Island, New York, spewing noxious fumes across Iceland and Europe.

The Bárðarbunga system is a geological giant, stretching approximately 120 miles long and 16 miles wide through Iceland's Eastern Volcanic Zone. Inside the middle of it stands a central volcano reaching a height of 6,598 feet above sea level, and its 25-square-mile caldera is buried under a thick skin of glacier ice. One of six volcanic systems located beneath Europe's largest glacier, Vatnajökull, makes its behavior—and possible eruption scenarios—tough to predict, according to Barron's.

"The volcano is unusually large, with several possible scenarios for future developments," said the IMO representatives, according to Live Science. These scenarios include eruptions outside the caldera, as happened in 2014, but also one that carries a bit more risk: an eruption beneath the glacier inside the caldera that could force explosive ash emissions and life-threatening glacial floods.

Recent seismicity has convinced the authorities to change the aviation color code from green to yellow due to precautionary reasons. While the volcano's remote location in Iceland's uninhabited highlands means no immediate risk to infrastructure, authorities are closely monitoring the situation. The earthquake swarm included 17 earthquakes with a magnitude of three or higher, at least two of them measuring magnitude four or above, stated CBS News.

According to IMO officials, the intensity of the earthquake swarm peaked at 8:05 A.M. when the largest earthquake struck. While this activity has, since then, reduced, the continued seismic events in the area indicate the continued process beneath the surface. According to experts, what was obtained presently showed an increase in magma buildup beneath the volcano—an ominous development, if there ever was any—after many months of raised seismic readings from the area.

Local experts, including Professor Magnús Tumi Guðmundsson, from the University of Iceland, have noted that this activity is distinct from other geological events in Iceland, stated Iceland Monitor. To begin with, the earthquake swarm around Bárðarbunga has nothing to do with yet another current event—the flash flood at nearby Grímsvötn lakes—a fact that shows just how complicated and independent some of the volcanic systems in Iceland are vis-à-vis one another.