CR
Cryospheric Sciences

glacier

Image of the week – Micro-organisms on Ice!

Image of the week – Micro-organisms on Ice!

The cold icy surface of a glacier doesn’t seem like an environment where life should exist, but if you look closely you may be surprised! Glaciers are not only locations studied by glaciologists and physical scientists, but are also of great interest to microbiologists and ecologists. In fact, understanding the interaction between ice and microbiology is essential to fully understand the glacier system!


Why study micro-organisms on glaciers?

Micro-plants, micro-animals and bacteria live and reproduce in cryoconite ecosystems on the surface of glaciers. Cryoconite is a dark coloured material (Fig. 2) found at the bottom of cylindrical water-filled melt holes (cryoconite holes) on a glacier surface; it consists of dust and mineral powders transported by the wind, and micro-organisms. Cryoconite holes are formed as the dark coloured material causes localised melting, due to reduced albedo (ability of a surface to reflect solar energy).

Figure 2: Example of a Cryoconite hole filled with dark cryoconite material (markers are 10×10 cm) [Credit: Tommaso Santagata – La Venta Esplorazioni Geografiche]

Because organisms in cryoconite thrive in extreme conditions, they are very unique and interesting to study. Information about their genetic makeup and chemical structure can help to inform, for example, medical and pharmaceutical sciences. Currently, however, information on their community structure is still limited.

Cryoconite ecosystems are very isolated and must work together to survive and thrive. Some micro-organisms (e.g. micro-algae) can photosynthesise and are able to live autonomously inside cryoconite holes using atmospheric carbon dioxide, sunlight, water and chlorophyll. By this same mechanism, they can find all the molecules essential for their vital and structural needs and consequently they generate most of the molecules necessary for all other living things. For example, the waste product of photosynthesis, oxygen, is essential for the survival of all organisms living in aerobiosis in these communities. Due to their key role in the ecosystem, the micro-algae are known as “primary producers”.

As around 70% of the earth is covered in water, which is colonised by micro-algae, studying the way they survive in extreme conditions and how they contribute to the ecosystem is of global importance – especially at this time of climate change.

The diversity of highly active bacterial communities in cryoconite holes makes them the most biologically active habitats within glacial ecosystems.

Data collections – Six days on THE glacier

The Perito Moreno glacier (Fig. 3) is known as one of the most important tourist attraction in Argentinian Patagonia (see our previous IOW post). Each day, hundreds of people observe the impressive front of this glacier and wait to see ice detachments and hear the loud sound of it’s impacts in the water of Lake Argentino. The glacier takes it’s name from the explorer Francisco Moreno, who studied the Patagonian region in the 19th century. The glacier is more than 30 km in length and an area of about 250 km2, Perito Moreno is one of the main outlet glaciers of Hielo Patagonico Sur (southern Patagonia icefield).

Figure 3: Aerial view of the Perito Moreno
[Credit : Tommaso Santagata – La Venta Esplorazioni Geografiche]

In April 2017, after several missions to the Greenland Ice Sheet to study extremophilic micro-organisms (organism that thrive in extreme environments) of ice, a team of Italian and French scientists organised a scientific expedition to study the microbiology of Perito Moreno. The expedition was organised by La Venta and Spélé’Ice and included researchers from several French and Italian Universities (see below for full list)

Perito Moreno is very well known, especially to the La Venta team, who have been organising scientific expeditions in Patagonia since 1991. The microbiological research objectives of this mission were to study the micro-organisms that live on the surface of Perito Moreno and compare them to results obtained in the other polar, sub-polar and alpine regions. The multi-disciplinary research team were able to set up a complex field laboratory, which included a microscope and an innovative small tool size capable of DNA sequencing. This meant that samples could be analysed immediately after their extraction from the ice (Fig. 1).

Getting all the equipment and personnel to achieve this expedition onto the ice was not an easy task. The team and their equipment were transported by boat to a site near the front of the glacier. Equipment then needed to be transported to the Buscaini Refugee, a shelter used as a base-camp by the team (Fig. 4). This took two trips, on foot, of about 7 hours (12 km of trail along the lateral moraine and the ice of the glacier with very heavy backpacks) – not an easy start! Luckily this hardship was somewhat mitigated by the absence of extreme cold, in fact, abnormally hot weather tallowed the team to move and work in t-shirts – not bad!

Figure 4: Walking into the field site along the ice of Perito Moreno – part of the 12km of trail to the Buscaini Refugee shelter
[Credit: Alessio Romeo – La Venta Esplorazioni Geografiche]

Thanks to these favourable weather conditions, all the goals were achieved in the short amount of time the team were allowed to camp on the glacier (special permission is needed from the national park to do this). During the five days of activity, many samples were taken and sequenced directly at the camp by the researches. Other important goals, such as morphological comparisons and measurements of the velocity of the glacier through the use of GPS, laser scanning and unmanned aerial vehicles were achieved by another team of researchers (stay tuned for another blog post about this!).

Universities and research institutes involved: University Bicocca of Milan – Italy, University of Milano – Italy, Sciences of the Earth A.Desio – Italy, Natural History Museum of Paris – France, University Diderot of Paris – France, University of Florence – Sciences of the Earth – Italy, University of Bologna – Italy.

Further Reading

Edited by Emma Smith


Tommaso Santagata is a survey technician and geology student at the University of Modena and Reggio Emilia. As speleologist and member of the Italian association La Venta Esplorazioni Geografiche, he carries out research projects on glaciers using UAV’s, terrestrial laser scanning and 3D photogrammetry techniques to study the ice caves of Patagonia, the in-cave glacier of the Cenote Abyss (Dolomiti Mountains, Italy), the moulins of Gorner Glacier (Switzerland) and other underground environments as the lava tunnels of Mount Etna. He tweets as @tommysgeo

Image of the Week – Drilling into a Himalayan glacier

Image of the Week – Drilling into a Himalayan glacier

How water travels through and beneath the interior of debris-covered glaciers is poorly understood, partly because it can be difficult to access these glaciers at all, never mind explore their interiors. In this Image of the Week, find out how these aspects can be investigated by drilling holes all the way through the ice…


Hydrological features of debris-covered glaciers

Debris-covered glaciers can have a range of hydrological features that do not usually appear on clean-ice valley glaciers, such as surface (supraglacial) ponds. These features are produced as a result of the variable melting that occurs across the glacier surface, depending on the thickness of the debris layer on the surface. Melting is reduced where the debris layer is thick (e.g. near the terminus), which leads to mass loss primarily by thinning, rather than terminus retreat like clean-ice glaciers (read more about this process in this previous blog post). This produces a low-gradient surface covered by hummocks and depressions in which ponds can form, often with steep bare ice faces (ice cliffs) surrounding them. The occurrence of ice cliffs and ponds also affects the surface melt rate, as glacier ice in/on/under these features melts considerably faster (up to 10 and 7 times more, respectively) than that of the debris-covered areas surrounding them (Sakai et al., 2000). Consequently, these hydrological features are an important contributing factor to the general trend of surface lowering of debris-covered glaciers (Bolch et al., 2012).

As a result, most hydrological research on debris-covered glaciers to date has focused on the (more accessible) supraglacial hydrological environment, as well as measuring the proglacial discharge of meltwater from these glaciers, which is a vital water resource for millions of people (Pritchard, 2017). Below the debris-covered surface of these glaciers, next-to-nothing is known about their hydrology; do drainage networks exist within (englacial) or beneath (subglacial) these glaciers, can they exist, and how can they be observed in such challenging environments?

A limited amount of direct research has been carried out in attempt to answer some of these questions, such as speleological techniques to investigate shallow englacial systems on a few glaciers (e.g. Gulley and Benn, 2007; Narama et al., 2017). However, all other inferences of subsurface drainage through debris-covered glaciers have come from hydrogeochemical analyses of water samples taken from the proglacial environment (e.g. Hasnain and Thayyen, 1994) or interpretation of observed glacier dynamics from satellite imagery (e.g. Quincey et al., 2009). While relict englacial features can be observed on the surface of many debris-covered glaciers (Figure 2), studying these systems while they are still active is more difficult.

Fig. 2: A relict englacial feature in the centre of an ice cliff on Khumbu Glacier (looking downglacier), through which the associated supraglacial pond is thought to have drained in the past. Following the drainage event, the pond water-level would have dropped, exposing the ice cliffs around its edge and resulting in the pond water-level being too low to sustain a water flow through the channel. The inset shows the same feature from the far side (looking upglacier): on this side, a vast amount of surface lowering of the ice surface has occurred and the previously englacial channel is now visible from the surface. For scale, the feature is approximately 10 metres in height. [Large image credit: Evan Miles; Inset image credit: Katie Miles]

Hot-water drilling to investigate subsurface hydrology

One way in which potential hydrological systems beneath the surface of debris-covered glaciers can be investigated is through the use of hot-water drilling, as was carried out on Khumbu Glacier, Nepal Himalaya this year by the EverDrill team. A converted car pressure-washer was used to produce a small jet of hot, pressurised water, which was sent through a spool of hose into the drill stem to melt the ice below as it was slowly lowered into the glacier (our Image of the Week). The result (if all went well!) was a borehole 10-15 cm in width, that penetrated the ice all the way to the glacier bed (Figure 3). During the field campaign, we managed to drill 13 boreholes at 3 different drill sites across Khumbu Glacier, ranging in length from 12 to 155 metres.

Once the borehole has been drilled, it can be used to investigate the hydrology of the glacier in a number of ways. If the water level suddenly drops while drilling is in progress, it is possible that the borehole has cut through an englacial conduit, through which the excess drill water has drained. If it drops at the base of a borehole drilled to the bed, it can be assumed that some form of subglacial drainage network exists at the base of the glacier, and the excess water drained through this system. Such features can be examined further through the use of an optical televiewer (360° camera that is lowered slowly through the length of the borehole, taking hundreds of images to give a complete picture of the internal surface of the borehole), or by installing a variety of sensors along the hole’s length to collect various types of data.

Fig. 3: A borehole drilled into Khumbu Glacier during the EverDrill field season in Spring 2017. The borehole was approximately 10 cm in width. A small channel (to the left of the borehole) was formed during the drilling process to drain away the excess water as the borehole was drilled. [Credit: Katie Miles]


During the EverDrill fieldwork in Spring 2017, we televiewed three of the drilled boreholes. These boreholes were then instrumented with sensors to measure the temperature of the ice and, where the boreholes reached the bed, a subglacial probe to measure electrical conductivity, temperature, water pressure and suspended sediment concentration (turbidity). We have left these probes in the boreholes, so that we have measurements both through our field season and additionally through the monsoon summer months. This will allow us to see whether any subsurface hydrological drainage systems develop when there is an additional source of water contributing to the melting of these glaciers. We will return in October to collect this data, and hopefully find out a little more about the englacial and subglacial drainage systems of this debris-covered glacier!

Further reading

Edited by Morgan Gibson, Clara Burgard and Emma Smith


Katie Miles is a PhD student in the Centre for Glaciology, Aberystwyth University, UK, studying the internal structure and subsurface hydrology of high-elevation debris-covered glaciers in the Himalaya by investigating boreholes and measurements that can be made within them. She is also interested in the potential of Sentinel-1 SAR imagery in detecting lakes on the surface of the Greenland Ice Sheet. Katie tweets at @Katie_Miles_851, contact email: kam64@aber.ac.uk

Image of the Week – Ice on Fire (Part 2)

Image of the Week – Ice on Fire (Part 2)

This week’s image looks like something out of a science fiction movie, but sometimes what we find on Earth is even more strange than what we can imagine! Where the heat of volcanoes meets the icy cold of glaciers strange and wonderful landscapes are formed. 


Location of the Kamchatka Peninsula [Credit: Encyclopaedia Britannica]

The Kamchatka Peninsula, in the far East of Russia, has the highest concentration of active volcanoes on Earth. Its climate is cold due to the Arctic winds from Siberia combined with cold sea currents passing through the Bearing Strait, meaning much of it is glaciated.

Mutnovsky is a volcano located in the south of the peninsula, which last erupted in March 2000. At the base of the volcano are numerous labyrinths of caves within ice. The caves are carved into the ice by volcanically heated water. The roof of the cave shown in our image of the week is thin enough to allow sunlight to penetrate. The light is filtered by the ice creating a magical environment inside the cave, which looks a bit like the stained glass windows of a cathedral. It is not always easy to access these caves, but when the conditions are favourable it makes for a wonderful sight!

The Mutnovsky volcano is fairly accessible for tourists, around 70 km south of the city of Petropavlovsk-Kamchatsky. Maybe this could be the holiday destination you have been searching for?

Further Reading

We have featured a number of stories about ice-volcano interaction on our blog before, read more about them here, here and here!

Edited by Sophie Berger

Image of the Week – On the tip of Petermann’s (ice) tongue

Image of the Week – On the tip of Petermann’s (ice) tongue

5th August 2015, 10:30 in the morning. The meeting had to be interrupted to take this picture. We were aboard the Swedish icebreaker Oden, and were now closer than anyone before to the terminus of Petermann Glacier in northwestern Greenland. But we had not travelled that far just for pictures…


Petermann’s ice tongue

Petermann is one of Greenland’s largest “marine terminating glaciers”. As the name indicates, this is a glacier, i.e. frozen freshwater, and its terminus floats on the ocean’s surface. Since Petermann is confined within a fjord, the glacier is long and narrow and can be referred to as an “ice tongue”.

Petermann Glacier is famous for its recent calving events. In August 2010, about a quarter of the ice tongue (260 km2) broke off as an iceberg (Fig. 2). In July 2012, Petermann calved again and its ice tongue lost an extra 130 km2.

These are not isolated events. Greenland’s marine terminating glaciers are all thinning and retreating in response to a warming of both air and ocean temperatures (Straneo et al., 2013), and Greenland’s entire ice sheet itself is threatened. Hence, international fieldwork expeditions are needed to understand the dynamics of these glaciers.

Fig. 2: The 2010 calving event of Petermann. Natural-color image from the Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite ( August 16, 2010).  [Credit: NASA’s Earth Observatory]

The Petermann 2015 expedition

In summer 2015, a paleoceanography expedition was conducted to study Petermann Fjord and its surroundings, in order to assess how unusual these recent calving events are compared to the glacier’s past. Our small team focused on the present-day ocean, and specifically investigated how much of the glacier is melted from below by the comparatively warm ocean (that process has been described on this blog previously). In fact, this “basal melting” could be responsible for up to 80% of the mass loss of Petermann Glacier (Rignot, 1996). Additionally, we were also the first scientists to take measurements in this region since the calving events.

Our results are now published (Heuzé et al., 2017). We show that the meltwater can be detected and tracked by simply using the temperature and salinity measurements that are routinely taken during expeditions (that, also, has been described on this blog previously). Moreover, we found that the processes happening near the glacier are more complex than we expected and require measurements at a higher temporal resolution, daily to hourly and over several months, than the traditional summer single profiles. Luckily, this is why we deployed new sensors there! And since these have already sent their data, we should report on them soon!

Edited by David Rounce and Sophie Berger

References and further reading

Katabatic winds – A load of hot (or cold) air?

Katabatic winds – A load of hot (or cold) air?

It might seem obvious that a warming world will lead to a reduction in glacial ice cover, but predicting the response of glaciers to climatic change is no simple task (even within the short term). One way to approach this problem is to come up with relationships which describe how glaciers interact with the world around them, for example, how the ice interacts with the air above it. Our post today delves into the world of ice-air interaction and describes some of the problems encountered by those who are investigating it, in particular the problem of modelling katabatic winds! Not sure what we are talking about…then read on to find out more! 


What are katabatic winds?

Anyone who has stood on, or in front of a glacier on a clear, sunny day has no doubt felt the bitter chill of a katabatic wind, forcing them to don a warm jacket and lose their chance at that lovely “glacier tan”. Katabatic winds (derived from the Greek word katabasis, meaning ‘downhill’) develop over snow and ice surfaces because the 0°C ice surface cools the air just above it. This cold, dense air then flows downhill under the force of gravity (Fig. 1 and Fig. 2). This is not recent news and such wind chill has no doubt punished glaciologists and explorers for the last century or more –  Mawson’s Description of the 1911-1914 Australian Antarctica Expedition is aptly named “The Home of the Blizzard“. However, despite being well known, this phenomenon still causes much uncertainty when it comes to modelling the melting of glacier ice surfaces around the world.

Soon gusts swept the tops of the rocky ridges, gradually descending to throw up the snow at a lower level. Then a volley raked the Hut, and within a few minutes we were once more enveloped in a sea of drifting snow, and the wind blew stronger than ever. – Mawson, 1915, The Home of the Blizzard

Figure 2: The view from the upper reaches of Tsanteleina Glacier in the western Italian Alps (Val d’Rhemes, Aosta). Katabatic winds generally flow in a down-glacier direction – here, from right to left [Credit: T Shaw].

Challenges for modelling

Air temperature is really important in determining how much a glacier melts and we need to know as much about it as possible to provide accurate predictions now and into the future. This is particularly relevant because the warmer it gets, the more energy is available to melt ice and seasonal snow. Unfortunately though, we don’t have an infinite supply of meteorological observations (e.g. air temperature, wind speed etc) at many locations we are interested in. As a result, we have to make simple assumptions about what the weather is doing at a remote, far away glacier. One such simple assumption is based upon the fact that air temperature typically decreases with increasing elevation, and so if we know the elevation of a location we are interested in, we can assume a ‘likely’ temperature. The rate of change in temperature with elevation is known as a ‘lapse rate’.

Air temperature is really important in determining how much a glacier melts…the warmer it gets, the more energy is available to melt ice and seasonal snow.

When predicting glacier melt, it is common practice to use a lapse rate which stays constant in time and space. This is convenient as we often don’t know the actual lapse rate at a given location, but this often ignores things happening at the surface of the Earth. An important example of this is when we have katabatic winds over glaciers!

When conditions are warm, and skies are clear, the cooling of the air above the ice surface, means that the application of a lapse rate is fairly useless, or close to it [Greuell and Böhm, 1998]! That is because the cooling from the surface continues as air flows down the glacier, typically creating colder temperatures at lower elevations, the opposite of the typical lapse rate assumption that models will apply.

‘Bow-shaped’ temperature vs. elevation relationships

To complicate matters for people trying to model the air temperature over glaciers, the effect of surface cooling is not just dependent on the amount of time an air parcel is in contact with the ice surface but also the characteristics of the ice surface it has been in contact with. In fact, after cooling on their descent down-glacier, air parcels have been documented to warm again, leaving interesting slightly “bow-shaped” curves to the temperature-elevation relationship. This effect has been found for the Swiss Haut Glacier d’Arolla and the Italian Tsanteleina Glacier (Fig. 3c,d). A new model approach to tackling this bow-shaped problem has been presented by recent research [Ayala et al., 2015] and offers a means of accounting for katabatic winds in glacier models. Nevertheless, more data and more work are still needed to generalise these models [Shaw et al., in review].

Figure 3: Relationship between elevation and air temperature on three different glaciers in the western Alps. Miage (Italy), Tsanteleina (Italy) and Arolla (Switzerland). Glaciers are represented using the mean of all data available (green), the top 10% of off-glacier temperatures (P90 – red) and the bottom 10% of off-glacier temperatures (P10 – blue), plus one standard deviation. The debris-covered Miage Glacier does not demonstrate a classic katabatic flow regime and therefore temperature corresponds well to elevation even under warm conditions [Credit: T Shaw, unpublished].

after cooling on their descent down-glacier, air parcels have been documented to warm again, leaving interesting slightly “bow-shaped” curves to the temperature-elevation relationship.

Air temperatures across debris-covered glaciers

As you may have read in our previous post on the topic, debris-covered glaciers behave in a different way to those with a clean ice surface. Detailed observations of air temperature across a debris-covered glacier show that the glacier responds to the heating of surface debris in the sunlight and a consequent warming of the lower atmosphere [Shaw et al., 2016]. Because of this, air temperature conforms very strongly to the elevation dependency that is assumed when using a lapse rate. Although very local variations of air temperature on other debris-covered glaciers cannot be well estimated by a lapse rate [Steiner and Pellicciotti, 2016], the insulating effect of thick debris cover means that the current approach to using simple lapse rates for estimating air temperature over debris-covered glaciers could be suitable.

Nevertheless, challenges for accurately representing air temperature above glaciers without debris cover remain. The fact that globally averaged temperatures are expected to rise over the current century (areas at high latitudes have shown a stronger warming trend) [Collins et al, 2013], the applicability of using lapse rates could further diminish. Recent patterns of warmer-than-average temperatures also suggest a difficulty of accurately estimating on-glacier temperatures in the short-term. For example, for the period of May 2015 – August 2016, every month beat the previously held record for warmest globally average temperature (GISTEMP). Imagine the bow-shaped problem to that!

Edited by Matt Westoby and Emma Smith


Thomas Shaw is a PhD student in the Department of Geography at Northumbria University, UK. His research is focused on the spatial and temporal variance in near-surface air temperature across debris-covered and debris-free glaciers in the western Italian Alps. As well as conducting research in the Alps, he is also very interested in glaciers and their processes on Svalbard (Norwegian Arctic) and has spent plenty of time studying above, or within (!), ice at high latitudes. Contact e-mail: thomas.shaw@northumbria.ac.uk

Image of the Week – Climate Change and the Cryosphere

Image of the Week – Climate Change and the Cryosphere

While the first week of COP22 – the climate talks in Marrakech – is coming to an end, the recent election of Donald Trump as the next President of the United States casts doubt over the fate of the Paris Agreement and more generally the global fight against climate change.

In this new political context, we must not forget about the scientific evidence of climate change! Our figure of the week, today summarises how climate change affects the cryosphere, as exposed in the latest assessment report of the Intergovernmental Panel on Climate Change (IPCC, 2013, chapter 4)


Observed changes in the cryosphere

Glaciers (excluding Greenland and Antarctica)

  • Glaciers are the component of the cryosphere that currently contributes the most to sea-level rise.
  • Their sea-level contribution has increased since the 1960s. Glaciers around the world contributed to the sea-level rise from 0.76 mm/yr (during the 1993-2009 period) to 0.83 mm/yr (over the 2005-2009 period)

Sea Ice in the Arctic

  • sea-ice extent is declining, with a rate of 3.8% /decade (over the 1979-2012 period)
  • The extent of thick multiyear ice is shrinking faster, with a rate of 13.5%/decade (over the 1979-2012 period)
  • Sea-ice decline sea ice is stronger in summer and autumn
  • On average, sea ice thinned by 1.3 – 2.3 m between 1980 and 2008.

Ice Shelves and ice tongues

  • Ice shelves of the Antarctic Peninsula have continuously retreated and collapsed
  • Some ice tongue and ice shelves are progressively thinning in Antarctica and Greenland.

Ice Sheets

  • The Greenland and Antarctic ice sheets have lost mass and contributed to sea-level rise over the last 20 years
  • Ice loss of major outlet glaciers in Antarctica and Greenland has accelerated, since the 1990s

Permafrost/Frozen Ground

  • Since the early 1980s, permafrost has warmed by up to 2ºC and the active layer – the top layer that thaw in summer and freezes in winter – has thickened by up to 90 cm.
  • Since mid 1970s, the southern limit of permafrost (in the Northern Hemisphere) has been moving north.
  • Since 1930s, the thickness of the seasonal frozen ground has decreased by 32 cm.

Snow cover

  • Snow cover declined between 1967 and 2012 (according to satellite data)
  • Largest decreases in June (53%).

Lake and river ice

  • The freezing duration has shorten : lake and river freeze up later in autumn and ice breaks up sooner in spring
  • delays in autumn freeze-up occur more slowly than advances in spring break-up, though both phenomenons have accelerated in the Northern Hemisphere

Further reading

How much can President Trump impact climate change?

What Trump can—and can’t—do all by himself on climate | Science

US election: Climate scientists react to Donald Trump’s victory  | Carbon Brief

Which Trump will govern, the showman or the negotiator? | Climate Home

GeoPolicy: What will a Trump presidency mean for climate change? | Geolog

Previous posts about IPCC reports

Image of the Week — Ice Sheets and Sea Level Rise

Image of the Week —  Changes in Snow Cover

Image of the Week — Atmospheric CO2 from ice cores

Image of the Week — Ice Sheets in the Climate

Edited by Emma Smith

Sea Level “For Dummies”

Sea Level “For Dummies”

Looking out over the sea on a quiet day with no wind, the word “flat” would certainly pop up in your mind to describe the sea surface. However, this serene view of a flat sea surface is far from accurate at the global scale.

The apparent simplicity behind the concept of sea level hides more complex science that we hope to explain in a simple manner in today’s “For Dummies” post, which will give you the keys to understand the important aspects of past sea change, and an ability to look into and understand how sea level is a key factor in the future.

Everyone will be familiar with news stories about current sea level rise, but it can be very confusing to understand what this means in real terms; how fast it is happening and why we should care about it anyway. So to begin with, let’s have a look at what we mean by sea level?


Sea Level – It’s all about gravity!

[Read More]

Image of the Week — Arctic porthole, Arctic portal

Image of the Week — Arctic porthole, Arctic portal

No need to be a superhero to momentarily escape your everyday life!
For that you, can just rely on the EGU Cryosphere Blog, which cares for taking you on trips to all sorts of remote and cool places (OK, OK we have to admit that some of these places are indisputably cold 🙂).

The picture of this week was taken through the porthole of a boat in the middle of Isfjorden, one of the largest fjord in Svalbard .

What is Svalbard and why should we care about it?

Svalbard is not only the mythical home of Phillip Pullman’s armoured bears but it also an archipelago (island cluster) north of Norway, in the Arctic circle. 60 % of its surface is covered by glaciers (1615 in total) which hold enough ice to raise global sea level by 19mm. These glaciers are very varied, covering a wide range of different ice dynamic types. For example – you can find tidewater glaciers (terminating at floating ice shelves in the sea), surging glaciers (which experience cycles of rapid speed-up and slow-down) and ice caps (on the Eastern Islands).

Svalbard is a place for adventurous cryospheric fieldwork related on this blog and the subject of much scientific study, but here are a few reason why this place is significant:

  • Enhanced warming is currently occurring in the Arctic as a result of polar amplification.
  • The glaciers and ice caps in Svalbard are currently losing 5 ± 2 Gigatons of ice per year (IPCC, 2013).
  • Despite its very northern latitude (74° to 81° north), the climate in Svalbard is relatively warmer than in other islands at the same latitude. This due to the influence of the warm north Atlantic current that, in the winter, warm Svalbard up to 20°C, compared to its Russian and Canadian Arctic counterparts.

Does anyone live there?

It may surprise you to know that the Svalbard area counts more polar bears (~3500) than people living there (~2,650) ! Being sparsely populated, however, doesn’t prevent the Archipelago from having human activities such as coal mining, tourism and scientific research.


The image comes from imaggeo, what is it?

You like this image of the week? Good news, you are free to re-use it in your presentation and publication because it comes from Imaggeo, the EGU open access image repository.

(Edited by Emma Smith)