The earth split as if along a seam: a new volcanic eruption in Iceland

The most intense eruption in the recent series on Iceland’s Reykjanes peninsula has commenced, according to Professor of Geophysics Magnus Toomey. Fortunate to soon embark on a helicopter survey of the area, he witnessed the magnificent spectacle firsthand.

The sight was indeed remarkable. Lava burst forth from a newly formed fissure, propelled by immense pressure, resembling a formidable wall. The lava flows rapidly expanded across the landscape, encroaching upon the coast near the historic town of Grindavik.

In addition to other natural geological wonders, there is the Swarzengi volcanic system, characterized by numerous cracks, craters, cones, and remnants of past eruptions in the form of solidified lava fields.

For eight centuries until 2019, the underground magma remained dormant. However, it proved beneficial for humans: the renowned geothermal resort “Blue Lagoon” is located here, where one could capture stunning photographs in the warm blue pools set against the iconic Icelandic landscapes—blanketed with snow in winter and a mix of black and green in summer; this is also the site of the Swarzengi geothermal station.

Data from the station was instrumental in predicting the impending eruption. Increasing pressure in the wells indicated that subterranean tension was mounting, signaling that magma was about to surface. Scientists started discussing the eruption a couple of weeks before it commenced on May 29.

It occurred: the land north of Grindavik split open. From the widening fissure, red-orange magma erupted in a fiery display.

Geophysicist Kristina Jónsdóttir reported lava fountains reaching at least 50 meters high, showcasing the force of the erupting magma.

By 16:00 local time, the fissure had extended 1.5 km. Less than an hour later, at 16:46, it had grown to 2.5 km, with the earth continuing to fracture. The latest update at 18:28 indicated the gap had reached 3.4 km. At this point, the eruption’s intensity was evident as the fissure expelled 1000 cubic meters of lava every second.

The red color marks a new fissure created by the eruption. The yellow signifies the defensive structures erected at the onset of volcanic activity on the Reykjanes Peninsula. The gray area represents the expanse of lava that has been discharged.

The assertion that the “Sundhnukur volcano” is erupting is not entirely accurate. Sundhnukur refers to ancient craters within the Swarzengi volcanic system. This designation is applied to the specific section where the fissure emerged, splitting and enveloping one of these craters to the north and south.

As lava interacted with groundwater, it generated vast clouds of dark gray steam and surged through the area, melting an asphalt road and electrical lines.

Grindavik, a city established by Vikings, has lost power. Lava has started to breach the protective barriers constructed at the start of the volcanic activity on the peninsula. However, most of these barriers have successfully fulfilled their purpose, preventing lava from encroaching on the city’s western flank.

Two roads leading to Grindavik were severed by surging lava flows, while others were obstructed by emergency services. Several dozen individuals who had stayed in the city despite escalating eruptions were evacuated. However, three Grindavik residents refused to leave their homes, requesting that rescuers let them be.

Icelandic volcanologists provide an optimistic outlook. Significant ground deformation occurred in the first two hours, then progressively subsided. The estimated volume of lava ejected since the eruption’s onset is 20 million cubic meters. Calculations suggest this volume is sufficient to alleviate the pressure built up in magma chambers. The situation is expected to stabilize gradually, with no further occurrences of 50-meter high lava fountains as seen on the initial day.