GeoLog

Iceland

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/.

What is in your field rucksack? Camping in Iceland

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When you head out into the field, which is the one item you can’t do without? For Rebecca Williams, a volcanologist at the University of Hull, good footwear is essential!

Inspired by a post on Lifehacker on what your average geologist carries in their rucksack/backpack, we’ve put together a few blog posts showcasing what a range of our EGU members carry in their bags whilst in the field!

Beautiful, eyrie, the land where fire meets ice: Iceland. An Earth scientist’ dream, complete with lava, volcanoes, earthquakes, impossible landscapes, ice, snow, the ocean…Iceland, is a top destination for many scientist who want to better understand the processes which shape our planet. Among them, Rebecca Williams, a volcanologist at the University of Hull, who spent a few days camping on the volcanic island this summer.

This bag belongs to: Rebecca Williams, University of Hull.

Field Work location: Þórsmörk, Iceland

Duration of field work: 10 days

What was the aim of the research?: I was working with Dave McGarvie and Jonathan Moles, from the Open University. They are working on a volcano in the area and had come across the Þórsmörk Ignimbrite. Ignimbrites are the deposits from pyroclastic density currents. This unit is quite complicated and not well understood. It is best exposed in Þórsmörk, so we spent 4 days here doing a recce of the exposure in the Þórsmörk area, trying to understand its many facies and their relationship to each other. I then spent the remainder of the time with a field assistant (Steph Walker from Royal Holloway) doing some detailed work on the best exposures, collecting some samples and recording the details of the deposit. We also recce’d some new areas to try to determine the extent of the deposit and finding new localities for future work.

The one item I couldn’t live without:

Footwear! We covered over 10 miles of rough ground and varied terrain each day, so good footwear is essential. I was very thankful for the trekking sandals when fording the rivers. One fording point is on the famous Laugavegur trekking from the hot springs area of Landmannalaugar to the glacial valley of Þórsmörk. We would often see people trying to ford the river in trainers, crocs and even bare feet! It was clear that this wasn’t ideal, and from some of the screeches, very difficult! But in these trekking sandals, I was able to wade over in relative ease and comfort.

Rebecca in the field. Credit: Rebecca Williams

Rebecca in the field. Credit: Rebecca Williams

In the picture of me in the field, you can see what I actually carry when I’m out and about. The zip off trousers were great for fording rivers – I wasn’t expecting it to be hot enough in Iceland to wear them to work! Strapped to my bag are my sandals for fording rivers, and my hammer. The poles were great for getting around on slopes like the one in the background, and for helping out when fording rivers. Here I’m also carrying a spade – acquired once in Iceland. This is unusual for me, I’m used to working with much harder rocks like the welded ignimbrites in Pantelleria. The spade was very useful for digging through scree slopes and material broken up and crushed by glaciers.

 

If you’ve been on field work recently, or work in an industry that requires you to carry equipment, and would like the contents of your bag to feature on the blog, we’d love to hear from you. Please contact the EGU’s Communication Officer, Laura Roberts (networking@egu.eu)

Announcing the winners of the EGU Photo Contest 2016!

Announcing the winners of the EGU Photo Contest 2016!

The selection committee received over 200 photos for this year’s EGU Photo Contest, covering fields across the geosciences. Participants at the 2016 General Assembly have been voting for their favourites throughout the week  of the conference and there are three clear winners. Congratulations to 2016’s fantastic photographers!

 Glowing_Ice. Credit:  Vytas Huth (distributed via  imaggeo.egu.eu). Ice on Jokulsarlon beach in Iceland. Ice calving off the Breidamerkurjokull, one of the glaciers comprising the Vatnajokull, the largest glacier in Iceland. The is retreating rapidly, and in the process has created a large glacial lagoon known for its spectacular icebergs.

Glowing_Ice. Credit: Katharine Cashman (distributed via imaggeo.egu.eu). Ice on Jokulsarlon beach in Iceland. Ice calving off the Breidamerkurjokull, one of the glaciers comprising the Vatnajokull, the largest glacier in Iceland. The is retreating rapidly, and in the process has created a large glacial lagoon known for its spectacular icebergs.

 'Living flows'. Credit:  Marc Girons Lopez (distributed via  imaggeo.egu.eu). River branches and lagoons in the Rapa river delta, Sarek National Park, northern Sweden. The lush vegetation creates a stark contrast with the glacial sediments transported by the river creating a range of tonalities.

Living flows’. Credit: Marc Girons Lopez (distributed via imaggeo.egu.eu). River branches and lagoons in the Rapa river delta, Sarek National Park, northern Sweden. The lush vegetation creates a stark contrast with the glacial sediments transported by the river creating a range of tonalities.

 'There is never enough time to count all the stars that you want.' . Credit:  Vytas Huth (distributed via  imaggeo.egu.eu). The centre of the Milky Way taken near Krakow am See, Germany. Some of the least light-polluted atmosphere of the northern german lowlands.

‘There is never enough time to count all the stars that you want.’ . Credit: Vytas Huth (distributed via imaggeo.egu.eu). The centre of the Milky Way taken near Krakow am See, Germany. Some of the least light-polluted atmosphere of the northern german lowlands.

In addition, this year, to celebrate the theme of the EGU 2016 General Assembly, Active Planet, the photo that best captured the theme of the conference was selected by the judges. The winner is the stunning ‘Mirror Mirror in the sea’, by Mario Hopmann! Congratulations! Scroll to the top of this post to view Mario’s image.

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: 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.