Published December 19, 2023
It was perhaps only a matter of time before Iceland’s Reykjanes Peninsula ran out of luck.
During the night of December 18, the peninsula exploded in a volcanic outburst—its fourth in under three years, and a decidedly dangerous entry in the nation’s volcanic saga.
Just two hours after a swarm of earthquakes warned of the impending eruption, it was firing out 10 times more lava per second than any of the past three at their peaks, all while the fissure itself expanded to an astonishing 2.5 miles in length in a matter of minutes.
After nearly a millennium of dormancy, this southwesterly strip of land entered a new volcanic era in March 2021. The past three eruptions—in 2021, 2022, and earlier this summer—were nothing less than scientific and aesthetic spectacles. The last time there was a period of multiple eruptions on the peninsula was in the early 13th century. That it is undergoing another similar span of lava-oozing eruptions is one reason the world has been watching so closely.
(Iceland has entered a new volcanic era.)
But this fourth eruption has caught the attention of the international media for another three reasons: the ramp up to the main event was unusual compared to the last three; the location, combined with its vigorous opening salvo of molten rock, threatens to destroy a town; and its overall behavior created an uncomfortable amount of uncertainty as to what may happen next.
“Just in context of the past three years on the Reykjanes Peninsula, it is pretty mind-blowing,” says Tom Winder, a volcano seismologist at the University of Iceland.
As of the afternoon of December 19, just a third of the fissure remains volcanically active, and the eruption’s output has greatly diminished. Things could still change for the worse, but hopefully it continues to fizzle.
Regardless, this volcanic pyre has already cemented its reputation as one of the most consequential and scientifically beguiling Icelandic eruptions of the last few decades—which is why scientists from across the world are on the case gathering clues to its origins.
A chaotic prelude
Although most people understandably think of volcanic eruptions as coming from a volcano, all four of the most recent eruptions have actually been fissure-style: when lava forces its way out of Earth’s crust through a newly formed thin crevasse, often at location that cannot be identified prior to the paroxysm. Unpredictable fissure eruptions happen around the world, including on Hawai‘i, but they aren’t as well known.
But this latest eruption is especially notable because it did something the 2021, 2022, and mid-2023 events didn’t. Instead of materializing once again in a secluded spot near the volcanic mountain of Fagradalsfjall, it made its underground way to Svartsengi—home to a region-critical geothermal power plant, the tourism hotspot Blue Lagoon spa,
