Magma beneath Svartsengi hits record volume, Grindavík reopens grocery store anyway

• Magma accumulation beneath Svartsengi has reached 23 million cubic metres, the highest since eruptions began on the Sundhnúkur crater row
• Eight months without eruption marks the longest pause in the current series — scientists say a new eruption is probable
• Grindavík's first grocery store since the late 2023 evacuation opened last week, with the owner expecting summer tourist traffic
• The most likely eruption zone remains the Sundhnúkur crater row northeast of Svartsengi

The magma reservoir beneath Svartsengi on Iceland's Reykjanes Peninsula has swollen to its largest volume since the Sundhnúkur eruption series began, with an estimated 23 million cubic metres of molten rock now pooled underground. RÚV reports that eight months have passed since the last eruption — the longest inter-eruption pause on record — and that scientists consider a new eruption probable. The most likely breach point remains the Sundhnúkur crater row, northeast of Svartsengi.

Land uplift and magma accumulation have been slow but steady in recent weeks, a pattern that Icelandic geoscientists have tracked through the entire eruption sequence that began in late 2023. Each previous cycle followed a similar script: gradual inflation, rising seismicity, then a fissure eruption. What distinguishes this cycle is its duration. More time means more magma, and 23 million cubic metres exceeds any previous inter-eruption accumulation in the series. The volume alone does not dictate timing — magma can sit for weeks or months before finding a path to the surface — but it raises the ceiling on how large the next eruption could be when it arrives.

Against this geological backdrop, Grindavík is quietly rebuilding. Last week, the town got its first grocery store since the mass evacuation in late 2023. No shop had operated in the town for over two years. Bjarney Högnadóttir, the store owner, told RÚV there was "a complete lack of any small shop to grab the essentials." Asked whether she worries about having to evacuate the store if a new eruption begins, she was blunt: "Not at all. We're used to everything. We'll just deal with it if we have to."

The store is quiet for now, but Högnadóttir expects business to pick up in summer. "There were a lot of tourists last summer, so I'm just expecting the same. Or hoping for it, at least." Tourism on the Reykjanes Peninsula has, paradoxically, benefited from the eruption series — visitors come to see the lava fields and active geology. That creates a peculiar economic dynamic: the same volcanic activity that displaced Grindavík's residents also draws the spending that could sustain its recovery.

Iceland's civil protection authorities maintain evacuation plans for Grindavík and surrounding areas, and the defensive barriers built to divert lava flows from critical infrastructure — including the Svartsengi geothermal power plant — remain in place. The monitoring network is dense: GPS stations, seismometers, and satellite data feed continuous updates to the Icelandic Meteorological Office. If the magma finds a way up, warning time is measured in hours, not days.

Högnadóttir stocked her shelves knowing all of this. The magma reservoir is fuller than it has ever been, the scientists say another eruption is a matter of when rather than if, and a shopkeeper in the evacuation zone is hoping for a good tourist season.

Sources: RÚV