Icelandic Volcano Made 68-Square-Mile 'Kettle'

The 2014 eruption was most violent in Europe since the late 1700s.

The most recent eruption of the Icelandic volcano Bardarbunga, which began on Aug. 29, 2014 and lasted for nearly six months, ranks as one of the most powerful in history. Fortunately, it wasn't as destructive as the legendary 1783 eruption of Laki, another Icelandic volcano, whose eight-month outburst spewed so much sulfur dioxide into the air that the resulting acid rain killed off most of the island's vegetation and caused about 10,000 people to die from starvation and disease, according to BBC.

But Bardarbunga's fury, while benign, led to one particularly startling record. According to a just-published study in the journal Science by researchers from the GFZ German Research Centre, Bardarbunga's caldera, or kettle--a bowl created when the volcano partially collapsed into itself, a rare occurrence--that covers 68 square miles, making it the biggest such structure ever observed.

RELATED: Mystery of Volcano Lightning Explained

The caldera, which was triggered by the intrusion of lava from 7.5 miles below the surface, carved out a bowl that grew over six months to about 6.8 miles across and 213 feet deep.

The German scientists used satellite images, seismological and geochemical data, GPS data and modeling to make their calculations.

FFZ researcher Thomas Walter notes that Bardarbunga could have been much more destructive of an eruption, if it actually had happened under the Vatnajökull, Europe's largest glacier, which partially covers the volcano. That would have led to a much bigger water vapor explosion and ash cloud.

WATCH: Why Does Earth Have Volcanoes?

"The event was a blessing in disguise," he said in a press release.

According to an account of the research in Atlas Obscura, scientists were already watching the volcano in August 2014 when the ground began to move, from one of the 77 earthquakes with a magnitude of 5 or greater that accompanied the eruption. About two or three weeks after the event began, the caldera started to form.

Calderas are relatively rare. According to Atlas Obscura, only seven such formations have occurred since 1900.