GeoLog

Iceland geology

Imaggeo on Mondays: In-tents Icelandic sunset

Imaggeo on Mondays: In-tents Icelandic sunset

This photograph was taken at the campsite near lake Mỳvatn during a field trip to Iceland. Every year a group of students from Wageningen University travels from the Netherlands to Iceland for a weeklong excursion as part of a course on catchment hydrology. The aim of the trip is to provide students with real life examples of the processes they learned during their lectures.

After a rainy morning that day, tents and equipment were packed away as quickly as possible in order to escape the wetness. The drive took the group from the campsite in Höfn, at the foot of the Vatnajökull glacier in southeastern Iceland, along the coastal highway up north towards Myvatn. Iceland is famous for its raw and beautiful nature, with waterfalls seemingly around every corner and the imposing presence of the glaciers and volcanos in the distance.

Upon our arrival at the campsite in the evening, people begrudgingly noticed that the tents were still wet from the morning rain. The campsite was situated at the bottom of a formidable hill, which provided stunning views over the lake and landscape. Not wanting to sleep in a damp tent, a few students picked up their tents, dismantled them, went up the hill and let the evening breeze do the rest, all amid the backdrop of a stunning sunset. The desire for dry covers even outweighed the very real danger of being eaten alive by masses of midges, a known pest and hazard in these parts.

When camping there is always things that can go wrong. But for places like Iceland it is the only way to truly appreciate and experience the country’s stunning beauty and wilderness. Gazing up at the northern lights from your sleeping bag is a once-in-a-lifetime experience. While waking up in the middle of the night and having to put on boots and jacket to run to the bathroom is vexing, you might be rewarded with views of the top of the glacier that has been shrouded in clouds all day, making it seem like Zeus himself is taking a peek down from Mount Olympus to see what is going on. Iceland has to be experienced, not from a cosy hotel bed, but from a tent put up in the evening and taken down the next day. As Albert Einstein once said: “Look deep into nature, and then you will understand everything better”. Even if that means hiking up a hill and holding your tent up into the wind to dry.

By Maria Warter, PhD student at Cardiff University

 

Imaggeo on Mondays: Iceland’s original birch forest

Imaggeo on Mondays: Iceland’s original birch forest

Iceland is a country of dramatically rugged landscapes. The region is home to sweeping valleys and mountain ranges, dotted with lava fields, large glaciers, hot springs and impressive waterfalls.

The territory is also notoriously treeless. As of 2016, forests only made up 1.9 percent of Iceland, according to the Icelandic Forest Service. However, about a thousand years ago the country’s landscape was far more vegetated, and remnants of Iceland’s original woodlands still exist today.

It is a common misconception that Iceland is too cold to sustain a forest. “On the contrary, it has been observed that, at the time of human settlement, birch woods and scrubs have covered large parts of Iceland,” said Marco Cavalli, a researcher at the Research Institute for Geo-Hydrological Protection in Italy and the photographer of today’s featured image. In fact, Iceland’s fossil evidence suggests that, before human settlement, 25-40 percent of the island was dominated by woodlands and thickets.

When humans migrated to the island about 1100 years ago, much of Iceland’s natural forests were chopped down to make way for fields and pastures. In the centuries following human settlement, intensive sheep grazing and volcanic eruptions prevented forests from regenerating. By 1950, less than one percent of the country was covered by trees.

Iceland’s vegetation-devoid state presents an environmental problem to local Icelanders, since the lack of trees, combined with the island’s volcanic activity, has left the land vulnerable to severe soil erosion. Since the soil conditions prevent vegetation from taking root, erosion has limited farming and grazing efforts. Iceland’s loose soil and strong winds are also responsible for damaging sandstorms.

Soil conservation and forestry services have made substantial efforts to repopulate the Icelandic environment with trees, just about doubling Iceland’s tree cover since the mid-20th century. However, there is still a long road ahead to reach the Icelandic Forest Service’s goal to see 12 percent of Iceland afforested by 2100.

This picture was taken by Cavalli while on a field trip in Rangárvellir, a southern region of Iceland near Gunnarsholt, the headquarters of the Soil Conservation Service of Iceland (SCSI). The workshop focused on the area’s severe degradation from both human activities and natural causes, and efforts to restore the ecosystem.

During the workshop he spotted this particular grove of dwarf birch trees. “I was impressed to see a small remnant patch of the Icelandic original birch forest resisting all these adverse conditions,” said Cavalli. “I would say this is a good example of nature fighting to survive.”

References

Forestry in a Treeless Land, Icelandic Forest Service

Changes in vegetation cover from the time of Iceland’s settlement, Icelandic Institute of Natural History

Vikings Razed the Forests. Can Iceland Regrow Them?, The New York Times

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: A lava layer cake

Imaggeo on Mondays: A lava layer cake

Brekkuselslækur, a small river, carves its way across Iceland’s ancient volcanic landscape. At Hengifoss, Iceland’s third-highest waterfall, it tumbles fiercely down thick, dark layers of lavas erupted from volcanoes some 18 to 2.58 million years ago, during a period of geological time known as the Tertiary.

Eruptions are rarely continuous; during hiatuses in the extrusion of lavas, ash is able to settle atop the smoldering layers. If the pauses are long enough and the conditions just right (a warm and humid climate is needed) the ashes, through the addition of clay and iron minerals, slowly turn to soil . When new lavas are layered over the top of the ash-rich soils, a chemical reaction takes place between the iron trapped in the soil and the oxygen transported by the lavas, to form iron oxide. In essence, the soils rust and turn a distinctive red colour.

As the process is repeated time and time again, layers of alternating black lavas and red soils are built up to form a giant ‘mille feuilles’ cake.

In the summer months, tourists flock to this popular site. An unspoilt view of the 188m high torrent means an early morning hike to beat the crowds. For a bird’s eye view of Hengifoss, the adventurous can even scarmble to the cliff tops too.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: harnessing Earth’s inner heat

Imaggeo on Mondays: harnessing Earth’s inner heat

Iceland, the land of ice and fire, is well known for its volcanicity. Most famously, it is home to Eyjafjallajökull: the volcano which caused wide spread mayhem across European airspace when it erupted in 2010.

But not all the local volcanic activity is unwelcome. High temperature geothermal areas are a byproduct of the volcanic setting and the energy released can be used to power homes and infrastructure. Indeed, geothermal power facilities currently generate 25% of the country’s total electricity production.

“I took the photograph during a three hour walk in the Krafla area, a few kilometres away from Myvatn Lake in Northern Iceland,” explains Chiara Arrighi, a PhD student at the University of Florence in Italy, who took today’s featured image while on a two week holiday on the island.

There are 20 high-temperature areas containing steam fields with underground temperatures reaching 250°C within 1,000 m depth dotted across the country. Krafla, a caldera of about 10 km in diameter, and the wider Myvatn area is one of them. The volcano has a long history of eruptions, which drives the intrusion of magma at (geologically) shallow depths which in turn heats groundwater trapped deep underground, generating the steam field. Only a few hundred meters from the shooting location a power station of 60 MW capacity exploits high- and low-pressure steam from 18 boreholes.

Fumaroles and mud pots, like the one photographed by Chiara, are the surface expression of the geothermal activity. The discoloration of the rocks in the immediate vicinity of the bubbling mire is due to the acidic nature of the water in the pool. The steam is rich in hydrogen sulphide, which oxidises to sulphur and/or sulphuric acid as it mixes with oxygen when it reaches the surface. It deposits around the vents of fumaroles and as sulphuric acid in the stagnant waters, leading to alteration of the surrounding bedrock and soil.

If you pre-register for the 2017 General Assembly (Vienna, 22 – 28 April), you can take part in our annual photo competition! From 1 February up until 1 March, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.