The merger of glaciers and ice caps could release a wave of volcanic eruptions, known as the study | Climate crisis
The merger of glaciers and ice caps by the climate crisis could release a dam of explosive volcanic eruptions, suggests a study.
The loss of ice releases the pressure on the chambers of underground magma and makes the eruptions more likely. This process was seen in Iceland, an unusual island which is on a border of tectonic plate in the middle of the Oriean. But research in Chile is one of the first studies to show an increase in volcanism on a continent in the past, after the end of the last glacial period.
The global heating caused by fossil fuels burns is now melting ice caps and glaciers around the world. The greatest risk of resurgence of volcanic eruptions is in Western Antarctica, the researchers said, where at least 100 volcanoes are under thick ice. This ice is very likely to be lost in the coming decades and centuries when the world warms up.
Volcanic eruptions can temporarily cool the planet by pulling particles reflecting sunlight in the atmosphere. However, sustained eruptions would pump significant greenhouse gases in the atmosphere, including carbon dioxide and methane. This would heat the planet more and potentially create a vicious circle, in which the increase in temperatures melts the ice which leads to new eruptions and a more global heating.
Pablo Moreno-Yaeger, at the University of Wisconsin-Madison, in the United States, which led research, said: “While glaciers are withdrawing due to climate change, our results suggest that these volcanoes continue to break out more frequently and more exploded.”
The research, which was presented at the Goldschmidt Geochemistry Conference in Prague, and is in the last stages of the revision with an academic review, involved high camping in the Andes, among active and dormant volcanoes.
Detailed work on a volcano, called Mocho-Choshuenco, used the dating of radio-isotopes to estimate the age of volcanic rocks produced before, during and after the last ice age, when the patagonia ice cap 1,500 meters thick has covered the area. The analysis of minerals in rocks also revealed the depth and temperature at which the rocks were formed.
These data revealed that the thick ice coverage had deleted the volume of eruptions between 26,000 and 18,000 years, allowing a large magma tank to accumulate 10 to 15 km (6.2-9.3 miles) below the surface. After the ice melted, about 13,000 years ago, the pressure on the magma chamber was released, the gases in the liquid or the melted rock extended and the explosive eruptions followed.
“We found that after the deglaciation, the volcano begins to break out much more and also changes composition,” said Moreno-Yaeger. The composition changed when the magma melted the crustal rocks while the eruptions were deleted. This made the molten rock more viscous and more explosive on the eruption.
“Our study suggests that this phenomenon is not limited to Iceland, where increased volcanity has been observed, but could also occur in Antarctica,” he said. “Other continental regions, such as parts of North America, New Zealand and Russia, also deserve more in-depth scientific attention.”
Previous research has shown that volcanic activity has increased globally by two to six times after the last ice age, but the Chilean study was one of the first to show how it happened. A similar phenomenon was reported via the analysis of rocks in eastern California in 2004.
A recent review of scientists revealed that there had been relatively little study on how the climate crisis had affected volcanic activity. They said that more research was “of extremely important importance” in order to be better prepared for damage caused by volcanic eruptions to people and their livelihoods and for possible climate-volcano feedback loops which could amplify the climate crisis. For example, more extreme precipitation should also increase violent explosive eruptions.
