Imaggeo on Mondays: Snow and ash in Iceland

Imaggeo on Mondays: Snow and ash in Iceland

Featuring today on the blog is the land of ice and fire: Iceland. That title was never better suited to (and exemplified), than it is in this photograph taken by Daniel Garcia Castellanos in June 2013. Snow capped peaks are also sprinkled by a light dusting of volcanic ash. Dive into this post to find out the source of the ash and more detail about the striking peak.

The picture is dominated by a snowed mountain in Southern Iceland, captured in June 2013, three years after the Eyjafjallajökull eruption. When Eyjafjallajokull erupted, it sent ash kilometers high into the atmosphere disrupting the air traffic in most Europe for weeks.

“This striking Icelandic landscape also inspired Tolkien’s fantasy in The Lord of the Rings,” explains Daniel, a researcher at the  Instituto de Ciencias de la Tierra Jaume Almera, in Barcelona.

Eyjafjallajokull is located in the Eastern Volcanic Zone in southern Iceland and the area photographed is among the youngest (less than 0.7 yr in age) and most active areas of Iceland, right on the contact where the Eurasian and the North American tectonic plates meet.The black rock seen in the image is tephra – fragments of rock that are produced when magma or or rock is explosively ejected (USGS) – from the neighboring Torfajökull rhyolitic stratovolcanic system, know for its cone shaped volcanoes built from layer upon layer of lava rich in silica and consequently very viscous. The light-green colour consists of the ubiquitous Icelandic moss.

In the image, the remnants of winter white snow are dotted with fine grey ashes from the Eyjafjallajökull 2010 eruption (about 30 km to the south of this image). Years after the Eyjafjallajökull eruption, the volcano still burns hot and its lighter ashes are still blown over southern Iceland providing this magical colors over the entire region.

Daniel’s adventures in Iceland didn’t stop at simply photographing stunning volcanic landscapes. He also had the privilege to see the inside of one of the volcanoes in the Eastern Volcanic Zone close up. Watch his descent into the Thrihnukagigur volcanic conduit over on his blog, Retos Terrícolas.

Imaggeo on Mondays: Gothic Snow Architecture.

Whilst on a family holiday in Norway, Gerrit de Rooij took this incredible photograph of an ice arch. Understandably geoscience is not his top priority whilst taking photographs on holiday, however Gerrit points out that pretty much every picture of a landscape has hydrology in there somewhere”, as he goes on to describe below.

This picture was taken near Balestrand, a village along the Sognefjord in Norway (Norway’s largest fjord and the second largest in the world!). The altitude was approximately 900 m above sea level (asl), and not always does all snow vanish during summer over there (we were there in August 2013). What you can see in the picture are the remnants of a much thicker snow pack that covered the stream that trickles down. On the right hand side you can see a glimpse of the other side of the arch that  must have gradually been carved out by the stream during the snow melt season (as they call spring over there). Once a tunnel was carved out, thaw took over. The black lines of rock dust on the ridges of the snow arch presumably were left behind by water streaming down along them from the top of the melting snow cover. In the top rim the source of this material is still visible.

Gothic Snow Architecture. (Credit: Gerrit de Rooij via

Gothic Snow Architecture. (Credit: Gerrit de Rooij via

Exposed are ancient rocks, heavily eroded by several glaciations and subsequent Holocene freeze-thaw cycles and snow melt flows. The location of the picture is on the west side of Norway’s mountain range. These mountains force western winds from the Atlantic upward, which makes the air cool down and release a lot of its moisture. The very frequent rains (we had 3 rain free days out of 16) create lush vegetation at lower altitudes (the tree line is between 600 and 700 m asl) and sustain extensive moss carpets higher up, as visible in the image. In places where the rock face is too steep to support moss, lichen covers it, which is evidence of very clean air – lichen are highly sensitive to air pollution.

The stream (and many similar streams nearby) feed a small lake that supplies Balestrand with drinking water. The lake can be reached in a day from Balestrand, but hiking further requires an overnight stay, even for most Norwegians, rugged as they may be. There are no huts or any other facilities, so you need to carry your camping gear with you. We camped a little higher without seeing anybody, and from the condition of the trails it was clear that everything beyond the reach of a day trip was used very infrequently. This unperturbed state, the abundant precipitation, and the inertious rocks made the water of the lake crystal clear (several meters of visibility) and very poor in nutrients (hardly any underwater vegetation), making it an excellent source of local drinking water.

In the composition, I liked the two halves of the snow arch mirroring each other, and the fact that the lines and the slope of the large exposed rock face are similar to those in the larger snow arch. The bright green of the moss upslope adds liveliness and draws the eye. I have a relatively simple camera (you want something light when backpacking) and at the time had no software to manipulate my pictures so I had to choose my viewpoint carefully and work with the light that was there. I scooped and stood very close to the snow to create a sense of perspective and have the arch reach over the camera.

By Gerrit de Rooij, Helmholtz Centre for Environmental Research – UFZ, Halle (Saale), Germany


Imaggeo is the EGU’s open access geosciences image repository. Photos uploaded to Imaggeo can be used by scientists, the press and the public provided the original author is credited. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. You can submit your photos here.

GeoCinema Online: Our changing Climate

Welcome to the third instalment of Geocinema! The focus this week is on climate change and how it impacts on local communities. Sit back, relax and make sure you’ve got a big bucket of popcorn on the go, as this post features a selection of short documentaries as well as trailers of feature length films.

Documenting the effects of the warming conditions on the surface of our planet is the primary focus of many researchers but understanding how these changes directly affect communities is just as important. The two are intrinsically linked and the films this week  highlight just to what extent this is true.

Thin Ice

In this feature film, a global community of researchers, from the University of Oxford and the Victoria University of Wellington, race to understand the science behind global warming and our planet’s changing climate.

Find detailed information of the project here.


High Mountain Glacial Watershed Program

How are communities in mountainous regions affected by significant watershed? In the film, scientist try to find a way to better manage these events.


The wisdom to Survive

What are the challenges of adapting to an ever changing climate? The film explores how we can adjusts to living in the wake of this significant challenge through talking to leaders in the realms of science, economics and spirituality.


Glacial Balance

Humans have depended on supplies of water since the dawn of mankind.  Ever changing weather patterns means supplies of water are shifting and communities are having to relocate to access fresh provisions. Glacial Balance takes us on a journey from Colombia to Argentina, getting to know those who are affected by melting glacial reserves in the Andes.


Enjoyed the series so far? There are more films you can catch up on here and here.

We will explore further facets of our ever changing planet in the next instalment of GeoCinema, stay tuned to the blog for more posts!


Thin Ice: Keith Suez,

High Mountain Glacial Watershed Program : Daniel Byers,

The Wisdom to Survive: Gwendolyn Alston,

Glacial Balance: Ethan Steinman,

Imaggeo on Mondays: Plate it up – a recipe for sea ice errors

Last week, a team of cryospheric scientists published a paper in The Cryosphere that showed how tiny plates of ice can lead to spurious estimates of sea ice thickness. This week, we’re featuring their findings, as well as some spectacular sea ice images in the latest in our Imaggeo on Mondays series…

Viewing the poles from above is a stunning sight – a seemingly endless expanse of brilliant white, ridged blue crests, and delicate grey fringes that stretch like lace over the ocean. Such a vantage point also allows scientists to get to grips with what’s happening to these delegate fringes, seeing how far the sea ice stretches from year to year and how its thickness changes over time.

One of the best ways to measure how thick a large expanse of sea ice is, is to measure its elevation, comparing it to the level of the surrounding water to see just how much is floating on the ocean. This can be done swiftly using satellites, which have the added bonus of keeping a continuous record of change over time. But recent research reveals there may be a problem with this technique.

Spying on sea ice from some 20,000 feet above the surface. (Credit: NASA)

Spying on sea ice from some 20,000 feet above the surface. (Credit: NASA)

Beneath sea ice you find a fine crystalline mush composed of thin ice crystals, or platelets. These platelets bridge the boundary between sea ice and the sea below. Because ice is buoyant, this icy mush (aka the sub-ice platelet layer) pushes the sheet of sea ice upwards, increasing its elevation. Small differences in the proportion of platelets below the ice could make it appear thicker than it really is, leading to inaccurate measures of sea ice thickness.

Looking out over Antarctic sea ice. (Credit: Andrew Chiverton via

Looking out over Antarctic sea ice. (Credit: Andrew Chiverton via

To know just how big a difference these platelets make, first you need to know how much solid ice is present in the mush. Using drill hole data collected in 2011, a team of scientists from New Zealand and Canada estimated that solid platelets made up about 16% of the mush beneath Antarctic sea ice. It may not sound much, but this many platelets could cause ice thickness to be overestimated by almost 20%.

You also need to know just how dense the platelets are. If they have a very low density, they can buoy the ice up more, and if they’re denser, they will have less of an affect on sea ice thickness. The findings mean a fair bit of ground-truthing will be needed to get better estimates of sea ice thickness from satellites in the future.

By Sara Mynott, EGU Communications Officer


Price, D., Rack, W., Langhorne, P. J., Haas, C., Leonard, G., and Barnsdale, K.: The sub-ice platelet layer and its influence on freeboard to thickness conversion of Antarctic sea ice, The Cryosphere, 8, 1031-1039, 2014.

Imaggeo is the EGU’s open access geosciences image repository. Photos uploaded to Imaggeo can be used by scientists, the press and the public provided the original author is credited. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. You can submit your photos here.