Watch this audio slideshow of the new lava on Fimmvörduháls mountain ridge between the glaciers Eyjafjallajökull and Mýrdalsjökull in south Iceland, where a volcanic eruption took place between March 20 and April 12. It is now possible to hike across the lava, which is still hot, and look at glowing magma in crevasses.
Fimmvörduháls is a mountain ridge between the glaciers Eyjafjallajökull and Mýrdalsjökull in south Iceland. The path across the ridge from Skógar to Thórsmörk is among the most popular hiking paths in the country. It is 22 kilometers long and has an elevation of 1,000 meters.
The south-north route is especially beautiful because there is an unusually high number of waterfalls in the Skógá river and the view on the way down from the ridge of the highland oasis of Thórsmörk is breathtaking.
On March 20, 2010 a volcanic eruption began on Fimmvörduháls, which lasted until April 12. The lava flow from the crater formed a 200-meter long lava fall, which cascaded into the canyons Hrunagil and Hvannárgil. Two mounds were formed around the craters, which have been named Magni and Módi.
In July the hiking route across Fimmvörduháls was reopened with a new path marked across the new lava, which is still hot and red-hot magma can be spotted in crevasses.
Ingi Rúnar Bragason, a cabin guard at Básar in Thórsmörk, said the hike across the new landscape on Fimmvörduháls is unique. “It is a magnificent sight, foreigners who come here are at loss of words for describing this experience,” he told pressan.is in late July, expressing his surprise that many more foreign tourists than Icelanders had hiked across the new lava.
In June white spots were noticed in the river Hvanná, which have been monitored by geologists since. They were created when carbon dioxide from the lava was carried into the river. Such precipitations are common in the Geysir area but very rare in cold water. However, it is dangerous to go close to the river because of toxic gases.
The following is an excerpt from the article ‘The Volcanic Eruption in Fimmvörduháls’ by volcanologist Haraldur Sigurdsson at the Volcano Museum in Stykkishólmur, west Iceland, published in the print edition of Iceland Review, issue IR 48.01 2010.
Once again we are thoroughly reminded by a natural disaster that Iceland is a very active volcanic country. The eruption in Fimmvörduháls, starting just before midnight 20 March, had a long prelude. In 1994 a series of earthquakes under the volcano started at a depth ranging from 5 to 14 kilometers. This seismic activity occurred again in 1996, 1999 and 2000. Then it became evident that magma was breaking through, deep from the earth’s mantle but it had stopped in the middle of the earth’s crust. The earthquakes were caused by magma intrusions, which happen when magma breaks through the layers of the earth’s crust, like thin wedges of molten steel.
The overall picture of the crust beneath the volcano is like that of a Christmas tree, with many branches and wedges of magma intrusions and channels, but all this happened deep under the earth’s surface.
Geologists immediately became wary because Eyjafjallajökull is a powerful volcano. Eruptions took place there in the years 920, 1612 and most recently in 1821 to 1823. In January 2010 seismic activity increased once more with a series of deep earthquakes. The earthquakes increased in number little by little and the earth’s crust started to rise upwards, which pointed to magma thrusting up through the layers of rock. In March alone more than 1,200 quakes were recorded under the mountain but all were deep. On 18 March several shallow quakes occurred in Fimmvörduháls ridge east of the volcano, and two days later an eruption resumed on the northernmost part of the ridge. A fissure had formed pointing north, right on the mountain ridge above the beautiful Thórsmörk valley.
To begin with as many as twelve fire fountains were active on the rift, like a row of gigantic glowing candles, but they got fewer as the eruption progressed until only four or five craters were active. The eruption spews lava at a temperature of about 1200 degrees Centigrade, or nearly 2500 degrees Fahrenheit, and the magma erupting is of the basalt kind which is the most common type of magma in Iceland. It forms viscous blocky lava which initially streamed north and fell from the mountain ridge from a height of more than one hundred meters down Hrunagil canyon, crawling through the canyon towards Thórsmörk. When the glowing hot lava fell over ice and snow in the canyon it created huge, extremely hazardous steam explosions which tore the hot lava apart and formed huge ash plumes.