2023-12-19 19:00:54
Late on Monday evening, the earth on Iceland’s southwestern tip finally cracked. This was preceded by five weeks of uncertainty about a possible outbreak on the southern coast of the Reykjanes peninsula. Videos and photos from the night show glowing lava fountains shooting up from a fissure and lava flows flowing out of the side of the fissure. There had previously been more than 350 earthquakes in the region on Tuesday night.
For geologist Matt Genge from Imperial College London, the images are typical of eruptions in Iceland. “The lava appears to be hot and liquid.” This basalt lava, which can reach temperatures of up to 1,200 degrees, is typically mined on the Mid-Atlantic Ridge. Along this boundary, the North American and Eurasian plates are moving away from each other. Basaltic molten rock then oozes out of the Earth’s mantle. Magma often accumulates on its way to the surface before erupting at the surface.
“About ten times as much magma”
There is another geological peculiarity on the Reykjanes peninsula. It is due to a leaky transformer fault. The plates slide past each other laterally, but at the same time they spread out slightly, which facilitates the formation and rise of magmatic melts. “About ten times as much magma erupts in Iceland as on the rest of the Mid-Atlantic Ridge,” says Genge.
In fact, the rate of lava production at the beginning of the eruption, up to 100 cubic meters per second, was significantly higher than that of the previous eruptions in 2021, 2022 and the summer of 2023. Then, as now, the eruptions occurred in the Fagradalsfjall volcanic complex, northeast of the already in the November evacuated fishing village Grindavík.
According to the Icelandic Meteorological Office, the activity of the volcanic eruption decreased towards the morning, but the decreasing activity is not an indication of an imminent end. “It is very difficult to say how long these eruptions will last. It could be days or months. Larger, more intense eruptions tend to last for a shorter period of time, but if the flow rate becomes low it can continue for some time,” says volcanologist Sam Mitchell from the University of Bristol.
Whether the eruption becomes a threat to Grindavík’s power plants and the nearby Blue Lagoon depends largely on the topography, says geologist Genge. “The lava continues to flow downhill until it cools enough to stop, and there is little you can do to redirect it.”
Ulf von Rauchhaupt Published/Updated: Recommendations: 10 Julian Staib Published/Updated: Recommendations: 5 Published/Updated: Recommendations: 5
According to the experts, the current eruption does not pose a threat to air traffic. “This is a very different eruption than that of Eyjafjallajökull in 2010, where a large explosive eruption under a glacier created a very large cloud and very fine ash in the atmosphere generated,” says Mitchell. The current outbreak has a different mechanism. The lava flows out of the eruption fissure. This type of eruption produces hardly any ash.
#volcanic #eruption #Iceland #wont #affect #air #traffic