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Imaggeo on Mondays: Polygon ponds at sunset.

27 Oct

Thinking of the Arctic conjures up images of vast expanses of white icy landscapes punctuated by towering icebergs and a few dark rocky masses; certainly not a green landscape with a series of water pools amongst rolling hills. The image below is perhaps more reminiscent of the temperate Scottish or Welsh countryside; but don’t be fooled, out Imaggeo on Monday’s image was captured by Reinhard Pienitz  (Laval University, Canada) in western Bylot Island, part of the Canadian Arctic Archipelago.

Polygon ponds at sunset. (Credit: Reinhard Pienitz, via imaggeo.egu.eu)

Polygon ponds at sunset. (Credit: Reinhard Pienitz, via imaggeo.egu.eu)

The uniqueness of Bylot Island is due to the convergence of a number of ecosystems. It lies to the north of Baffin Island and is dominated by high mountain peaks and glaciers. The southern plain of the island is at relatively low-elevations and covered by tundra vegetation. Wetlands are common in the low lying terrain where grasses, brown moss and sedges carpet the landscape. Think of them as ‘polar oasis’ which support hundreds of plant species and tens of animal and bird species. In contrast, the slopes of the hills are much drier and support shrubs, grasses and forbs.

The ground in the low-lying areas is perpetually frozen which means the drainage of water from the melted snow is hampered; it is the presence of this permafrost which allows the formation of the widespread wetlands. Year on year, organic matter accumulates, rising upwards, as the permanently wet and cold conditions mean it is very difficult for organic material to break down. As time passes, cyclic layers of peat and permafrost build up. The importance of the wetland ecosystem in the Arctic cannot be underestimated. The peat-rich soils constitute a net sink for carbon during the Holocene and are thought to store 97% of the tundra carbon reserve (Ellis et al., 2008).

Freezing over the winter months and thawing over the (slightly) warmer spring months drives the formation of the polygonal pattern seen across the wetlands of Bylot Island (and many other Arctic regions). As the ground freezes it contracts resulting in the formation of vertical cracks which penetrate the layers of peat and permafrost. The moist soils and meltwaters mean that there is plenty of water available to infiltrate the cracks, especially during spring. As the cold winter months approach the water freezes and the cracks expand, forming what are known as ice wedges, commonly connected at the surface, which give rise to the well-ordered polygonal pattern.

 

References

Ellis, C.J., et al. (2008), Paleoecological Evidence for Transitions between Contrasting Landforms in a Polygon-Patterned High Arctic Wetland, Arctic. Antarctic, und Alpine Research., 40, 4,624-637

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: Trials and tribulations of field work.

17 Sep

Field work is not without its trials and tribulations, getting there, for instance can be an adventure in itself. Once you arrive you can expect long days, sandwiches for lunch and frustration at losing your way or equipment not working as you expect it to. Despite all of that, one of the primary draws of the geosciences is being able to spend time in the great outdoors. In the fourth instalment of GeoCinema there is something for everyone as we track scientist living in Antarctica, undergraduates trying to map a 15km2  area in Greenland and a PhD student who spends her time high up in the tree canopy. Grab a drink and get comfortable, the show is about to begin.

Are you ready? Inspirational moments in Antarctica

A short music video contains sequences of science in action which captures a little of how it feels to travel to and work in Antarctica.

British Antarctic Survey Halley Research Station

Living in Antarctica is no mean feat, especially whilst attempting to carry out lengthy field seasons, in fact, to some it might seem utter madness. However, the British Antarctic Survey’s Halley Research Station, a new facility to support world-leading science by offering living quarters as well as research facilities, has been built on the icy landscape.

An Undergraduate Mapping Project
This educational film follows 4 Oxford University undergraduates as they complete their mapping projects and describes the methodology used and experiences gained on the trip. It includes footage from Greenland, photographs and animated diagrams, making geology accessible to people with little knowledge of the subject. The main goal of the film is to inspire secondary school students to undertake fieldwork and study Earth Sciences.

Into the Deep Forest: Remote Sensing and Tropical Leaf Phenology: A PhD in the Amazonian Canopy.

Published research with its detailed graphs, elaborate methodologies and analysis doesn’t provide a means to showcase all the work that goes on behind the scenes. In this film a researcher showcases the first two years of her PhD, spent up high in the canopy of the Amazon rainforest.

 

Have you missed any of the series so far? Catch up with space science here or learn about carbon capture and storage instead.

Stay tuned to the blog for more films!

Credits

Are you ready? Inspirational moments in Antarctica: Linda Capper, http://youtu.be/8CmKwXXPkgg

British Antarctic Survey Halley Research Station: Linda Capper, http://www.youtube.com/watch?v=TDIi7rP_WBA

An Undergraduate Mapping Project: Eleni Wood, http://www.youtube.com/watch?v=Xd5H-14WLzA

Into the Deep Forest: Remote Sensing and Tropical Leaf Phenology: A PhD in the Amazonian Canopy: Cecilia Chavana-Bryant, http://vimeo.com/46676651.

Imaggeo on Mondays: Trapped air

8 Sep

Can you imagine walking into the depths of an icy, white, long and cavernous channel within a thick glacier? That is exactly what Kay Helfricht did in 2012 to obtain this week’s Imaggeo on Mondays photograph.

Tellbreen Glacier is a small glacier (3.5Km long) in the vicinity of the Longyearbyen valley in the Svalbard region of Norway. Despite its limited size, it is an important glacier. One of the key parameters scientist use to understand how glaciers are affect by a warming climate is how the melt water is transported through to the front of the glacier. The majority of models utilise data from temperate or polythermal glaciers, i.e., glaciers which have free water within the icy matrix. Tellbreen is a cold glacier, meaning the basal layers of ice are frozen to the glacier bed; despite the traditional view that cold glaciers are not able to store, transport and release water, Baelun and Benn, 2011 found Tellbreen does this year round.

Trapped air. (Credit: Kay Helfricht via imaggeo.egu.eu)

Trapped air. (Credit: Kay Helfricht via imaggeo.egu.eu)

Kay visited Tellbreen whilst at the Artic Glaciology course at the University Centre in Svalbard. ‘Each weak one excursion led us to glaciers in the vicinity of Longyearbyen’ says Kay, ‘this day we visited the glacier Tellbreen. Near the tongue of the glacier the outlet of an englacial channel enabled us to explore the inside of the glacier. We went for some tens of meters into the channel.’

What the group found were that the walls of ice either side of the channel contained impurities, from stones to gravel, as well as mud and also water. The image above shows ‘air trapped in the ice-walls of the conduit at a time when the conduit would have been filled with meltwater of the glacier’ explains Kay. Air accumulated in bubbles at the roof of the conduit. When the water in the conduit started to refreeze along the side-walls, these smooth lenticular bubbles were trapped and stored in the ice. Studying the bubbles and other impurities in the ice can give hints on the history of the glaciers ice flow and its thermal regime over several decades.

References

Baelum. K., Benn. D.I.: Thermal structure and drainage system of a small valley glacier (Tellbreen, Svalbard), investigated by ground penetrating radar, The Cyosphere, 5, 139-149, 2011

Naegeli. K., Lovell. H., Zemp. M., Benn, I. The hydrological system of Tellbreen, a cold-based valley glacier on Svalbard, investigated by using a systematic glacio-speleologicalapproach, Geophysical Research Abstracts, 16, EGU2014-6149, 2014 (conference abstract)

 

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

3 Sep

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!

Credits

Thin Ice: Keith Suez, http://thiniceclimate.org/

High Mountain Glacial Watershed Program : Daniel Byers, http://skyshipfilms.com/videos

The Wisdom to Survive: Gwendolyn Alston, http://vimeo.com/77314166

Glacial Balance: Ethan Steinman, http://www.glacialbalance.com/

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