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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/

Imaggeo on Mondays: A massive slump

1 Sep

One of the regions that has experienced most warming over the second half of the 20th century is the Potter Peninsula on King George Island in Antartica. It is here that Marc Oliva and his collaborators are studying what the effects of the warming conditions on the geomorphological processes prevailing in these environments.

“Permafrost is present almost down to sea level in the South Shetland Islands, in Maritime Antarctica” says Marc, “in some recent deglaciated environments in this archipelago, the presence of permafrost favours very active paraglacial processes”.

Permafrost is defined as the ground that remains frozen for periods longer than two consecutive years and constitutes a key component of the Cryosphere. However, it is not fully understood how it reacts to climate variability. In this sense, there is an on-going effort to improve our knowledge on these topics by carrying out long–term monitoring of permafrost, as well as of geomorphological processes, in order to better understand the response of the terrestrial ecosystems to recent warming trends.

This weeks’ Imaggeo on Mondays picture shows a massive slump and the exposed permafrost in the shoreline of a lake in Potter Peninsula (King George Island, Maritime Antarctica). Following the deglaciation of this ice-free area paraglacial processes are very active transferring unconsolidated sediments down-slope to the lake.

Slump-permafrost, Potter Peninsula, Antarctica. (Credit: Marc Oliva via imaggeo.egu.eu)

Slump-permafrost, Potter Peninsula, Antarctica. (Credit: Marc Oliva via imaggeo.egu.eu)

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.

Imaggeo on Mondays: Beneath a star-studded sky

4 Aug

Marco Matteucci captured this image of the night sky on the slopes of Mount Rosa, the second tallest peak in Alps. Mount Rosa straddles the border between southern Switzerland and Italy the pink mountain’s name comes from the Franco-Provençal word rouése, meaning glacier. Much off the Swiss side of the mountain is enveloped in the ice of Gorner Glacier, the second largest glacier in the Alps. On the Italian side, lies Belvedere Glacier, which is fed by the snow that falls on Mount Rosa.

Mount Rosa ridge, Valle d'Aosta, Italy. (Credit: Marco Matteucci via imaggeo.egu.eu)

Mount Rosa ridge, Valle d’Aosta, Italy. (Credit: Marco Matteucci via imaggeo.egu.eu)

Wish you could capture images like this yourself? You can! Take a look at this brief guide to space photography for some hints and tips. 

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.

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