Eruption Causes White Spots in Highland River Skip to content

Eruption Causes White Spots in Highland River

White spots caused by carbon dioxide being carried into the water from the lava on the Fimmvörduháls mountain range have been seen in river Hvanná in the highland resort Thórsmörk. The spots are an unusual sight and can prove to be dangerous.

The volcanic eruption on Fimmvörduháls. Photo by Páll Stefánsson.

Gas collects within depressions near the water and can cause suffocation—not long ago a doctoral student suffered mild intoxication when taking samples from the river. The carbon dioxide has formed precipitations at the bottom of the river, Morgunbladid reports.

“I would like to iterate that it is a little risky to go near the water and people have to be careful,” said geologist Sigurdur Reynir Gíslason at the University of Iceland Institute of Earth Science.

“These are calcium precipitations similar to those created by geothermal heat—the carbon dioxide binds with the rock and sort of flows like an invisible cloud with the water,” he explained.

“When calcium comes loose from the rock it forms these spots, which are certainly beautiful but the gas which flows above can be dangerous,” Gíslason stated, adding that such precipitations are common in the Geysir area but very rare in cold water.

The white spots in Hvanná were first noticed in June and have been monitored by geologists since. Last weekend members of the search and rescue association Dagrenning from Hvolsvöllur noticed the spots while walking in the area.

“I was walking with a large group of people and no one had seen anything like it before. The spots begin at the small lava flow which fell into the [Hvannárgil] canyon and reached down to the river but below the channel is milky white and the precipitations are hard as rock so it is impossible to pry a stone loose,” hiker Lars Hansen described.

“The water is clear and beautiful to watch but the bottom is completely milky white at a stretch of a few hundred meters,” he added. No one in his group noticed any discomfort while walking along the river, he said.

The volcanic eruption on Fimmvörduháls, March 20 to April 12, 2010, produced lava flows down the canyons Hrunagil and Hvannárgil.

Click here to read more about the eruption.

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!

Share article