Reykjanes Eruption: Man-made Protective Barriers Submerged By Lava Skip to content

Reykjanes Eruption: Man-made Protective Barriers Submerged By Lava

By Gréta Sigríður Einarsdóttir

Aerial view of lava flowing from the Geldingadalur crater and the audience gathered to admire it
Photo: Golli. Spectators admiring the eruption.

Lava from the Fagradallsfjall eruption is now flowing over both protective barriers erected in an effort to hinder its progress into Nátthagi, RÚV reports. The flowing lava is now only 2 km from the road along the southern coast of the Reykjanes peninsula but experts disagree on if and when it will reach the road if the eruption continues, with estimates ranging from a week or two to several months. Authorities are currently weighing their options for further measures to protect infrastructure from the eruption.

Lava could reach the road in weeks or months

Lava is now pooling in four places by the eruption site, in an unnamed valley south of the eruption, in Meradalir, Geldingadalir, and Nátthagi below the unnamed valley. The shortest route to the road along the peninsula is from Nátthagi, just over 2 km but lava from Meradalir could also reach the road. In addition to the road, authorities were interested in protecting some fibre optic cables in Nátthagi. Experts don’t agree on how long it would take the lava to flow from Nátthagi but have guessed that it would be from one or two weeks to one or two months.

Golli. The protective barriers were made from material found on-site and were meant to slow down the lava flow by allowing the lava to pool and gather
Golli. Hikers admiring lava from the Reykjanes eruption
Golli. The protective barriers were made from material found on-site and were meant to slow down the lava flow by allowing the lava to pool and gather

Authorities weigh options for further protective measures

Superintendent with the Department of Civil Protection and Emergency Response Rögnvaldur Ólafsson told RÚV that the protective barriers had been built because it was a relatively simple operation. Authorities are looking into what kind of structures can and should be erected to affect the flow of lava from the eruption to protect infrastructure in the area. “We’re looking into what options are in the situation. We started this operation in the mountain because it was a relatively simple operation. We hoped for better results but the conditions changed by the eruption site and the lava started streaming towards the south towards Nátthagi. So these barriers we erected lasted shorter than we had expected” Rögnvaldur stated.

Rögnvaldur stated that no decision has been made on what further protective measures will be erected in Nátthagi. When erecting the protective barriers, it was already foreseen that more extensive measures would have to be built. Asked what possible measure could entail, Rögnvaldur replied: “It would possibly be guiding barriers, directing the flow of the lava in a particular direction. Or we could erect similar barriers to the ones we made above Nátthagi, slowing the flow of the lava and allowing it to pool.”

Lava on the hiking trail could threaten eruption views

The road across the southern part of the peninsula isn’t the only trail in danger, as the lava is also flowing south towards Geldingadalir, approaching a mountain pass on the main hiking trail toward the eruption. If the eruption continues, the lava could cross the pass, flow over the hiking path thereby closing access to the hill closest to the crater. “[Preserving the hiking path] is less of a priority for us,” Rögnvaldur stated. “But it could happen that lava flows over the hiking path, in which case a new path will presumably have to be built.”

The protective barriers were erected at the height of 4 metres but were later raised to 8 metres. Only one of the barriers was fully built when lava started flowing over it, the other one stood at 6 metres. The structures were built from material from the area and while authorities weren’t confident the barriers would stop the lava, they hoped it would slow it down. Engineer Hörn Hrafnsdóttir who was in charge of the project stated that while the barriers likely wouldn’t stop the lava flow, their construction would offer valuable experience for future lava-related projects.

Below is a 3d model of the lava flow from the eruption since May 18, a few days before the lava crossed the protective barriers:

Aerial photos of the lava flow can also be seen on a map from the National Land Survey of Iceland.

Sign up for our weekly newsletter

Get news from Iceland, photos, and in-depth stories delivered to your inbox every week!

* indicates required

Subscribe to Iceland Review

In-depth stories and high-quality photography showcasing life in Iceland!