Iceland Volcano Update As Town's Cracked Ground at Risk of Collapse

The Icelandic town of Grindavík is at risk of collapsing in the aftermath of the recent volcanic eruption.

The volcano erupted on January 14, with lava pouring from fissures that opened at the edge of the town, setting fire to several of the houses.

Now, despite the eruption coming to a halt, these fissures are further endangering the town.

"The risk associated with cracks is still assessed as very high. It is the hazard that is now called 'crack collapse' and describes a hazard that may exist where cracks are hidden beneath an unstable surface that may give way," the Icelandic Met Office (IMO) said in a translated statement on Thursday. "The risk from crack movements is now estimated to be considerable."

The most recent eruption marked the second on the Reykjanes peninsula in the past month, and the fifth since 2021. The December eruption emerged around 2.5 miles away from Grindavík, but the January eruption saw lava pouring directly into the town. The 4,000 or so residents of Grindavík were evacuated on January 13 just before the volcano began erupting again in earnest.

"Iceland is sitting on the boundary between two tectonic plates - the Eurasian and North American plates, which are moving apart from each other. This drives melting of the mantle to create magma which eventually makes its way to the earth's surface to cause an eruption," Chris Firth, a volcano researcher at Macquarie University in Australia, told Newsweek.

"But it also explains how the location of the eruptions can move. The boundary between the plates creates a rift that magma can use to get to the surface. In this case, the magma has also been moving along the rift, rather than just moving vertically to the earth's surface. The current eruption is probably part of a wider series of linked eruptions that began in 2021 with the eruptions of Fagradalsfjall."

Now, the "crack collapse" may occur in areas of the town where the ground is already unstable, and could lead to the ground surface giving way. Additionally, another eruption may be imminent, due to the rate at which the ground is deforming to due magma gathering in the chamber beneath it.

"In recent days, land has risen by up to 8 mm per day, which is slightly faster than what was measured before the eruption on January 14," the IMO said in the statement. "At this point, it is difficult to say how much magma has accumulated since the eruption ended on January 16. It is likely that the time it takes to reach the same level of magma as before the last eruption is measured in weeks rather than days."

Despite the construction of rocky defenses at the edge of the town in an attempt to stem the flow of lava toward the houses and redirect it away, the eruption surged out of both sides of the barriers, and many of the buildings were inundated by the intensely hot stream of molten rock.

"The lava temperature would be in the range of 1,000-1,200 degrees Celsius. Unfortunately, its high temperature and power (think the force of hundreds of bulldozers pushing against something) mean that a lava flow can be incredibly destructive for infrastructure. There are efforts to build mounds and walls to try to divert the lava flows around parts of the town and these may make a difference as the lava flows are bound by gravity and will flow downhill taking the easiest path. At least they are relatively slow moving allowing some time for evacuation and management."

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