Iceland faces an ongoing volcanic threat affecting key infrastructure and 70% of the population on the Reykjanes Peninsula. Ongoing scientific analysis aims to predict future eruptions and their consequences using seismic and geochemical data.
Constant volcanic threats in Iceland
Using local earthquake data and geochemical data, researchers estimate that current volcanic eruptions in Iceland could last for years or even decades, threatening the country’s most populous region and vital infrastructure.
Eruptions on the Reykjanes Peninsula forced authorities to declare a state of emergency, a string of eight explosions since 2021. This southwestern region is home to 70 percent of the country’s population, has a single international airport and numerous geothermal power plants. those that provide hot water and electricity. The latest eruption in May and June led to the evacuation of residents and visitors to the Blue Lagoon geothermal resort, a popular tourist attraction, for the third time in more than two months.
The beginning of a new volcanic era
Iceland sits above a volcanic hotspot, where regular eruptions have occurred, but the Reykjanes peninsula has been dormant for 800 years. But the last volcanic episode lasted for centuries, leading scientists to predict that renewed volcanism will be the beginning of a long period.
The eruptions, an hour’s drive from the island’s capital Reykjavik, pose significant risks of economic disruption and leave evacuated communities uncertain about possible return.
Scientific analysis of volcanic activity
An international team of scientists has been monitoring the volcanoes for the past three years. By analyzing seismic tomography images and the composition of lava samples, they discovered parts of the geological processes underlying the new volcanic epoch. They predict that the region may have to prepare for repeated eruptions that will last years, decades, and possibly centuries.
The researchers report their findings in a paper published June 26 in the journal terra nova . The project involved collaboration between the University of Oregon, Uppsala University in Sweden, the University of Iceland, the Czech Academy of Sciences, and the University of California at San Diego. This study is the result of a previous study Nature Communication About Reykjanes’ first eruptions of 2021.
Future geological research and predictions
The island of Iceland consists almost entirely of lava, said Ilya Bindeman, a volcanologist and professor of earth sciences at the UO. The country lies on the Mid-Atlantic Ridge, a tectonic plate boundary separating North America and Eurasia. The drift of these plates can trigger volcanic eruptions as hot rocks from the Earth’s mantle (the planet’s middle and largest layer) melt and rise to the surface.
Bindemann said that while scientists know that current eruptions on the Reykjanes peninsula are caused by plate movement, the type of magma reservoirs and plumbing systems that feed them are unknown. The peninsula consists of eight volcanically active areas, so understanding whether there is a single common magma source or several independent sources and their depths could help predict the duration and impact of these eruptions.
Isotopic analysis to understand volcanism
Using geochemical and seismic data, the researchers investigated whether magma from the first eruption of a volcano on the peninsula between 2021 and 2023 came from the same source as magma from the most recent eruption of another volcano to the west.
Bindemann specializes in isotopic analysis, which can help determine the “fingerprint” of magma. Magma is composed primarily of eight elements, including oxygen and hydrogen, and 50 different trace elements in lower concentrations and different ratios. A unique combination of trace elements can help distinguish magma sources from one another. Scientists can also measure the amount of isotopes, elements that have the same chemical properties but different masses, in the magma. For example, oxygen has three different isotopes, Bindemann said.
“The air we breathe has a mixture of oxygen isotopes and we can’t tell the difference,” he said. “Their differences are not usually important for chemical reactions, but their recognition is important because their relative abundance in the magma can distinguish one magma source from another.”
When lava rock samples from two different volcanoes on the peninsula were analyzed, their similar fingerprints suggested the existence of a common magma storage area beneath the peninsula. Imaging of the Earth’s interior based on local earthquakes also revealed the existence of a reservoir at a depth of about 5.5 to 7.5 miles in the crust, the shallowest layer.
However, Bindemann said, this storage is ultimately fed by the melting of deeper rocks in the mantle, which can trigger eruptions that last for decades and spew magma across hundreds of square kilometers. The Icelandic hotspot would have no problem supporting this flow, he said. This marks the beginning of potentially sustained volcanic events in Iceland, although researchers are not yet able to fully estimate how long these episodes will last and the intervals between each one.
Unpredictability of volcanic activity
“Nature is never orderly,” Bindemann said. “We don’t know how long this will last and how often over the next ten or even a hundred years. A regularity will emerge, but nature always has exceptions and irregularities.”
Discussions continue over plans to safely drill into volcanic areas to learn about the geological processes that cause eruptions.
Volcanic activity is less variable and less explosive than eruptions elsewhere, giving scientists a rare opportunity to get close to fissures that are actively spewing lava, Bindemann said. He described it as a “laboratory of nature” that was both wonderful and terrifying.
“When you watch a volcano erupt, you feel like these are huge forces of nature and you feel like you’re so small,” Bindemann said. “These events are common on a geological scale, but they can be devastating on a human scale.”
Source: Port Altele
