CR
Cryospheric Sciences

Emma C. Smith

Emma is a post-doc at the Alfred Wegener Institute for Marine and Polar Research in Germany, using geophysics to investigate ice dynamics in East Antarctica. She completed her Ph.D. at The British Antarctic Survey and University of Cambridge earlier this year and is interested in all things icy and geophysical. She was lucky enough to be involved in fieldwork for the iSTAR Antarctica project and tweets as @emma_c_smith

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 – The Pulsating Ice Sheet!

Image of The Week – The Pulsating Ice Sheet!

During the last glacial period (~110,000-12,500 years ago) the Laurentide Ice Sheet (North America) experienced rapid, episodic, mass loss events – known as Heinrich events. These events are particularly curious as they occurred during the colder portions of the last glacial period, when we would intuitively expect large-scale mass loss during warmer times. In order to understand mass loss mechanisms from present-day ice sheets we need to understand what happened in the past. So, how can we better explain Heinrich events?


What are Heinrich Events?

During a Heinrich event large swarms of icebergs were discharged from the Laurentide Ice Sheet into the Hudson Strait and eventually into the North Atlantic Ocean. This addition of fresh water to the oceans caused a rise in sea level and a change in ocean currents and therefore climate.

We know about these events by studying glacial debris that was transported from the ice sheet into the oceans by the icebergs and eventually deposited on the ocean floor. From studying ocean-sediment records we know that Heinrich events occurred episodically during the last glacial period but not on at a regular intervals. Interestingly, when compared to temperature records from Greenland ice cores, it can be seen that the timing of Heinrich events coincides with the cold phases of Dansgaard–Oeschger (DO) cycles – rapid temperature fluctuations which occurred during the last glacial period (see our previous post).

the timing of Heinrich events coincides with the cold phases of Dansgaard–Oeschger (DO) cycles

What do we think causes them?

A new study, published last month in Nature, uses numerical modelling to show how pulses of warm ocean water could trigger Heinrich events. Our image of the week (Figure 1) illustrates the proposed mechanism for one event cycle:

  • a) Ice sheet at it’s full extent, grounded on a sill (raised portion of the bed, at the mouth of the Hudson Strait). Notice the sill is around 300m below sea level at this time.
  • b) A pulse of sub-surface water (purple) warms by a few degrees, encouraging iceberg calving at the glacier front and causing the ice begin to retreat from the sill.
  • c) As the ice retreats, it becomes unstable due to an inwards sloping bed (see our previous post on MISI). This leads to sudden rapid retreat of the ice – characteristic of Heinrich events.
  • d) Due to ice loss and thus less mass depressing the bed, the bed will slowly rise (Glacial Isostatic Adjustment), eventually the sill has risen to a level which cuts off the warmer water from the ice front and the ice can slowly advance again.

Once the ice has advanced back to it’s maximum extent (a) it will slowly depress the bed again, allowing deeper, warmer water to reach the ice front and the whole cycle repeats!

The authors of this study used this model to simulate Heinrich events over the last glacial period and were able to accurately predict the timing of Heinrich events, as known from ocean sediment records. Check out this video to see the model in action!!

Why is it important?

This study shows that the proposed mechanism probably controlled the onset of rapid mass-loss Heinrich events in the past and more generally that such mechanisms can cause the rapid retreat of marine terminating glaciers. This is important as it adds to our understanding of the stability (or instability) of present day marine terminating glaciers – such as the West Antarctic Ice Sheet! If such rapid mass loss happened regularly in the past we need to know if and how it might happen in the future!

such mechanisms can cause the rapid retreat of marine terminating glaciers.


Check out the full study and the news article summarising the findings here:

Image of the Week – It’s all a bit erratic in Yosemite!

Image of the Week – It’s all a bit erratic in Yosemite!

When you think of California, with its sun-soaked beaches and Hollywood glamour, glaciers may not be the first thing that spring to mind – even for ice nerds like us. However, Yosemite National Park in California’s Sierra Nevada is famous for its dramatic landscape, which was created by glacial action. With our latest image of the week we show you some of the features that were left behind by ancient glaciers.


What do we see here?

Although Yosemite is now largely glacier-free the imprint of large-scale glaciation is evident everywhere you look. During the last glacial maximum (LGM), around 26,000 to 18,000 years ago, much of North America was covered in ice. Evidence of this can be seen in the strange landscape, shown in our image of the week. The bedrock surface in this area is polished and smoothed due to a huge ice mass that was moving over it, crushing anything in it’s path. When this ice mass melted rocks and stones it transported were released from the ice and left strewn on the smoothed bedrock surface. These abandoned rocks and stones are know as glacial erratics. Some of these erratics will have travelled from far-away regions to their resting place today.

During the last glacial maximum (LGM), around 26,000 to 18,000 years ago, much of North America was covered in ice.

Glaciers that still remain!

There are still two glaciers in Yosemite, Lyell and Maclure, residing in the highest peaks of the National Park. Park rangers have been monitoring them since the 1930s (Fig. 2), so there is a comprehensive record of how they have changed over this period. Sadly, as with many other glaciers around the world this means a huge amount mass has been lost – read more about it here!

Figure 2: Survey on Maclure Glacier by park rangers in the 1930s [Credit: National Parks Service]

On a more cheerful note – Here at the EGU Cryosphere Blog we think it is rather fantastic that the park rangers of the 1930s conducted fieldwork in a suit, tie and wide-brimmed hat and we are hoping some of you might be encouraged to bring this fashion back! 😀

If you do please make sure to let us know, posting it on social media an tagging us @EGU_CR! Here are a few more ideas of historical “fieldwork fashion” to wet your appetite: Danish explorers in polar bear suits, 1864-65 Belgian-Dutch Antarctic Expedition and of course Shackleton’s Endurance expedition!


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.

Image of the Week – Blood Falls!

Image of the Week – Blood Falls!

If glaciers could speak, you might imagine them saying – “HELP!” The planet continues to warm and this means glaciers continue to shrink. Our new image of the week shows a glacier that appears to be making this point in a rather dramatic and gruesome way – it appears to be bleeding!


If you went to the snout of Taylor Glacier in Antarctica’s Dry Valley region (see map below) you would witness a bright red waterfall, around 15m high, flowing from the glacier into Lake Bonney. Due to it’s colour, this waterfall has acquired the somewhat graphic name: Blood Falls!

The Dry Valleys

Location of Taylor Glacier in Taylor Valley – one of the Antarctic Dry Valleys. The American McMurdo Research Station is located a short distance away [Credit: USGS via Wikimedia Commons ]

The dry valleys, as the name suggests, are considered one of the driest and most arid places on Earth – which seems like an unusual location for waterfall! The area is completely devoid of animals and complex plants, however, in finding an explanation for the colour of Blood Falls, scientists have also gained an insight into a whole ecosystem hidden beneath the Dry Valley glaciers.

Why is the water red?

The water that feeds Blood Falls is salty and rich in iron. This water is forced out from underneath the glacier by the pressure of the overlying ice (see schematic below) and as it emerges the iron in the water comes into contact with oxygen causing it to rust (oxidise) and turn the water red. But why is this water so salty and iron-rich in the first place? The story of how this unusual water came to be starts around five million years ago…

At this time, it is thought that the dry valleys were submerged beneath the ocean as part of a system of fjords (Mikucki et al., 2015). Subsequent uplift of this land and climatic cooling causing a drop in sea level left some of this salty ocean water isolated as a lake. Around 1.5 million – 2 million years ago a glacier started to form on top of this lake. The ice cut the lake off from the atmosphere and caused the lake water to become even more salty by the process of cryoconcentration (lake water in contact with the glacier ice is frozen, the salt is left behind in the lake increasing the concentration). Iron was introduced into the water from the bedrock beneath the lake, which was ground up as the ice moved over the top of it. There was also something else in this ancient sea water, that surprised scientists when they began to analyse the water from Blood Falls – microbes!

A schematic cross-section of Blood Falls showing how microbial communities survive in this hostile environment [Credit: Zina Deretsky, NSF ]

Life in the lake – Microbes

When it was covered in ice, this subglacial lake was very cold and cut off from the out side world – meaning no sun light and oxygen, which are normally essential for microbes to survive. However, the microbes in this lake are thought to have adapted to survive using sulphates and iron in the water (Mikucki et al., 2009).  This strange ecosystem is surviving in extreme conditions and shows how adaptable microbes can be. An area once thought to be too inhospitable to support much life has been shown to be much more “lively” than first thought – sparking up ideas about lifeforms in other inhospitable environments, such as Mars.

Further Reading

 

Edited by Sophie Berger

Image of the Week – Goodness gracious, great balls of ice!

Image of the Week – Goodness gracious, great balls of ice!

At first glance our image of the week may look like an ordinary stoney beach…but if you look more closely you will see that this beach is not, in fact, covered in stones or pebbles but balls of ice! We have written posts about many different weird and wonderful ice formations and phenomena (e.g. hair ice or ice tsunamis) here at the EGU Cryosphere blog and here is another one to add to the list – ice balls!


During the northern hemisphere winter these naturally formed balls of ice have been found on several Arctic shores; as well as Estonia there have been reports of them in RussiaNorth America and Northern Germany. There are even photos of “ball ice” in the Great Lakes from a 1966 book of aerial photography published by the University of Michigan. However, they are still a rare occurrence, surprising and delighting onlookers when they appear.

How do they form and why are they not seen more often?

These ice balls are thought to form from ice slush, which is amalgamated by turbulent water to form rough lumpy ice masses – similar to the way you would roll a small snow ball into a much larger one to form a snow man. The ice masses are then rounded into the smooth spherical shapes you see in our image of the week by wave action rolling them around in shallow water near the shore (see video below). This is much the same way as pebbles on a beach are smoothed and rounded – it just happens a lot faster with ice balls than solid pebbles!

It seems that the right combination of wind strength, wind direction, sea temperature and coast line shape are needed to form these features and then bring them on to the shore. For all of these things to occur at the same time is rare and special!

Image of The Week – Prize Polar Pictures!

Image of The Week –  Prize Polar Pictures!

Last week was the Fall APECS International Polar Week, designed to promote and celebrate the great collaborative science that goes on around the world to further our understanding of the polar regions. Part of this celebration was a figure competition, to find the most “eye-catching, informative and inspiring” figures that illustrate aspects of polar science.

What better, we thought, than to feature the winning figure as our Image of The Week? They say a image tells a thousand words and here at the EGU Cryosphere blog we wholeheartedly agree!


APECS International Polar Week

For the past 4 years APECS (The Association of Polar Early Career Scientists) have organised an International Polar Week each March and September. The International Polar Weeks are timed to coincide with the two equinoxes – the only times of year where the Northern and Southern hemisphere are equally illuminated by the sun – a rather nice way to tie our polar regions together!

International Polar Week highlights the importance of the polar regions and, in particular, provides an opportunity to develop new outreach activities in collaboration with teachers and educators. APECS have a fantastic catalogue of polar outreach resources for anyone wanting to spread the word about these diverse and important regions of Earth. They also organise events such as polar film festivals, talks and a figure competition. Today’s Image of The Week is the winning figure from the Polar Week figure competition, created by Noémie Ross as part of the A Frozen-Ground Cartoon outreach project.

A Frozen-Ground Cartoon”  – Where science meets art!

Thawing permafrost in Siberia [Credit: Guido Grosse via imaggeo ]

“A Frozen-Ground Cartoon outreach project was designed to help spread the word about permafrost and its crucial importance in our changing climate through thematic comic strips. Through these cartoons and comics the project aims to make permafrost science accessible to children, young people and the parents and teachers.

The project is funded by the International Permafrost Association and chaired by Frédéric Bouchard with a core group of young researchers from Canada, Germany, Sweden and Portugal providing the scientific information. The cartoons, one of which we feature today, are all designed by young artists.

Today’s image of the week highlights some of the ways that thawing permafrost will affect the lives of indigenous peoples in the Urals who live by reindeer-herding. This cartoon was based on the study of Istomin and Habeck (2016), and effectively provides an accessible way to communicate the key findings of this study to a general audience.

 

Edited by Sophie Berger

 


“A Frozen-Ground Cartoon” Team:

Project Leader: Frédéric Bouchard
Collaborators: Bethany Deshpande, Michael Fritz, Julie Malenfant-Lepage, Alexandre Nieuwendam, Michel Paquette, Ashley Rudy, Matthias B. Siewert, Ylva Sjöberg, Audrey Veillette, Stefanie Weege, Jon Harbor


Image of The Week – 100 years of Endurance!

Image of The Week – 100 years of Endurance!

The 30th August 2016 marks 100 years since the successful rescue of all (human) member of Shackleton’s Endurance crew from their temporary camp on Elephant Island (see map). Nearly a year prior to their rescue they were forced to abandon their ship – The Endurance – after it became stuck in thick drifting sea ice, known as pack ice, trying to navigate the Weddell Sea. It was the last major expedition of the Heroic Age of Antarctic Exploration and was well documented by Frank Hurley, the expedition’s photographer. Our post today brings you some of the stunning images he took over 100 years ago!


The Endurance

Ernest Shackleton. Image Credit: Scot Polar Research Institute.

Ernest Shackleton. Image Credit: Scot Polar Research Institute.

In August 1914 Ernest Shackleton set out with a crew of 27 men (chosen from over 5000 who applied!) on the ship Endurance, as part of the Imperial Trans-Antarctic Expedition. Their mission was to complete the first land crossing of Antarctica – from the Weddell Sea to the Ross Sea via the South Pole. Unfortunately disaster struck the Endurance in January 1915 when it became stuck fast in pack ice in the Weddell sea. True to the ships name the crew were forced to endure a very long journey home!

Our image this week shows the Endurance finally sinking through that pack ice into the depths on the ocean on the 21st November 1915, after being stuck in the pack ice for 10 months. Luckily, due to the fact it had been interned for such a long time, no members of the crew were on-board and much of the cargo had been removed, leaving the crew with food supplies and three small whaling boats to continue their journey.

Men wanted for hazardous journey. Low wages, bitter cold, long hours of complete darkness. Safe return doubtful. Honour and recognition in event of success.

E. Shackleton’s advertisement for his Imperial Trans-Antarctic Expedition (source: Watkins, 2012, p.1)

The long journey home!

Frank Hurley and Ernest Shackleton at camp, first published in the United States in Ernest Shackleton's book, South, in 1919., via Wikimedia Commons

Frank Hurley (expedition photographer) and Ernest Shackleton at camp. First published in the United States in Ernest Shackleton’s book, South, in 1919., via Wikimedia Commons.

On the 27th October 1915, shortly before the Endurance sank, Shackleton had given the order to abandon ship. The crew started to march towards open ocean pulling two of the whaling boats filled with supplied behind them. After a few days it became apparent that it was too difficult to move and the crew established a camp on the ice floe, know as “Ocean Camp”. At their camp on the ice the ship’s crew slept in tents but the dogs were housed in “dog igloos”. From this position supplies (including three whaling boat) were retrieved from Endurance, before she finally sank in November 1915.

Over the next few months the crew attempted further relatively unsuccessful marches to the ocean before eventually establish “Patience Camp” in December 1915 on the ice – which would be their home for more than three months. By April 1916 the ice floe had broken up and all 28 men piled into their three boats to head for Elephant Island which they successfully reached 5 days later. However, their journey was not yet over!

Elephant island was very remote and uninhabited with no real possibility of rescue, especially considering it was the middle of the first world war and many ships capable of making the journey from England were occupied in battle. Realising they needed to find their own assistance Shackleton and a skeleton crew of 5 men set sail in one of the small whaling boats, The James Caird, for a perilous 1,500 km journey to South Georgia where there were known to be inhabited whaling stations. They eventually landed safely on South Georgia a few weeks later, only to discovered they were on the opposite side of the island to the whaling station they had been counting on for help. Shackleton and 2 of his men set off on a 36-hour trek to reach Stromness whaling station, where they were eventually able to raise the alarm on the 20th May 1916. First they rescued the remainder of the 5 man crew from the other side of the South Georgia and then set out to rescue the remaining crew Elephant Island.

The launching of the James Caird from Elephant Island, in an attempt to reach the South Georgia. Photo Credit: Frank Hurley, the expedition’s photographer via Wikimedia Commons.

It wasn’t until  the 30th August 1916 that the men on Elephant Island were rescued, having spent over 4 months stranded there during the harsh Antarctic winter. Shackleton had made four attempts to rescue them, starting on 22nd May 1916, just three days after he had arrived in Stromness, however, each attempt had been thwarted by sea ice surrounding the island. Finally Shackleton managed to reach his crew in Yelcho, a small steam tug loaned to him by the Chilean government. He found all the men in a bad condition but alive, sadly the same cannot be said of the 69 dogs. Some of which died from ill health and many of which were eaten by the crew to survive those first months stranded on the ice.

A timeline and map showing the journey of the Endurance crew. Image credit: Luca Ferrario, DensityDesign Research Lab. CC BY-SA 4.0], via Wikimedia Commons

A timeline and map showing the journey of the Endurance crew. [Image credit: Luca Ferrario, DensityDesign Research Lab, via Wikimedia Commons.]

Where is The Endurance now?

Good question! There is a plan afoot to use Remotely Operated Vehicles (ROVs) to dive down to the sea floor and try to locate and film the remains of the Endurance, no firm details of the current state of this expedition seem to have been released yet, but it may be worth keeping your eyes on their twitter feed @IceProjectShack.

It still happens today!

On Christmas Day 2013 the Russian vessel the M.V. Akademik Shokalskiy got stuck in pack ice while returning from East Antarctica with a crew of scientists, media, and students onboard. Everyone was eventually rescued safely by collegues from China and Australia – unlike Shackleton’s era there is now a lot more support when people get into difficulty in Antarctica. However, a photographer onboard, Andrew Peacock noted that:

We have learned from nature, as humankind always does, that it’s possible to be caught by an unexpected and not predicted situation.

It seems that while the likelihood of rescue has improved over the past century, that we mere mortals are still at the command of nature!

Further Reading

Edited by Sophie Berger

Image of The Week – Tumbling Rocks

Image of The Week – Tumbling Rocks

This photo captures a rockfall at the summit of Tour de Ronde, 3792 m above sea level in the Mont Blanc Massif. On 27 August 2015, around 15000 m3  of rock fell from the steep walls of the mountain.

Why do mountains crumble ?

Rockfalls such as the one on the photo have been linked to thawing permafrost. The exact mechanism that leads to these events is not fully understood, however, it is thought that areas of the mountain becoming destabilised during thaw periods (Luethi et al, 2015). Records show that during heat waves — as for instance the one that happened in the summer of 2015 in the Mont Blanc Massif — there are many more rockfalls than during colder years. Researchers at the Université Savoie Mont Blanc have been monitoring this area of the Alps for many years, installing a network of temperature sensors on the surface and in boreholes drilled into the rock to try and better understand the link between temperature and rock slope stability (see Magnin et al, 2015).

What can we do about it? 

The short answer is that there is not a lot that can be done to prevent it. However, long term monitoring studies, such as the one from Magnin et al (2015), help to better understand what conditions are likely to result in rockfall activity and therefore predict when they are likely to happen. By doing this in the Mont Blanc region the team from Université-Savoie Mont Blanc has been able to put in place an alert network to warn the local community to increased rockfall activity. This means that the potential damage can be minimised, for example, by closing climbing routes in risky areas.


Further reading

Check out our blog post about how cryospheric research can transform lives.

  • Magnin, F., Deline, P., Ravanel, L., Noetzli, J., and Pogliotti, P. (2015) : Thermal characteristics of permafrost in the steep alpine rock walls of the Aiguille du Midi (Mont Blanc Massif, 3842 m a.s.l), The Cryosphere, 9, 109-121, doi:10.5194/tc-9-109-2015
  • Luethi, R., Gruber, S. and Ravanel, L., (2015) Modelling transient ground surface temperatures of past rockfall events: towards a better understanding of failure mechanisms in changing periglacial environments. Geografiska Annaler: Series A, Physical Geography, 97, 753767. doi: 10.1111/geoa.12114

(Edited by Sophie Berger)

Image of The Week – EGU General Assembly 2016

Image of The Week – EGU General Assembly 2016

The EGU General Assembly, which takes place each year in Vienna, Austria, draws to a close today.  Attended by nearly 13,650 participants from 111 countries, with around a third of those being students – a great turn-out for this vital part of the early career scientists (ECS) community!

It has been a very productive meeting for the cryosphere division with a huge number and variety of oral and post sessions covering a wide spectrum of the cryospheric sciences. This year a number of short courses were organised by your EGU Cryosphere blog team – including a meet the editor session with Frank Pattyn which is happening this afternoon, so get yourselves along to Room 2.85 at 13:30!

A cryosphere poster session at the 2016 EGU General Assembly. Photo Credit: Kai Boggild.

A cryosphere poster session at the 2016 EGU General Assembly. Photo Credit: Kai Boggild.

We have been lucky to have our very own and very talented Student Reporter Kathi Unglert reporting from the meeting this week, so look out for her reports from the meeting appearing on the blog soon. A great evening was had by all who attended the ECS cryosphere social on Wednesday night and we can’t wait until EGU 2017!

 

Image of The Week – The Ice Your Eyes Can’t See!

Image of The Week – The Ice Your Eyes Can’t See!

Ice sheets and glaciers are very visible and much photographed (e.g. hereelements of the Cryosphere but what about the vast, invisible and buried parts?  Around a quarter of the land in the Northern hemisphere remains frozen year round, making up a hugely important part of the cryosphere known as permafrost. Permafrost largely exists at high latitudes (e.g. Siberia and the Canadian Arctic) and these areas store a huge amount of carbon, around twice as much as currently exists in the atmosphere. As the global climate warms these frozen areas of ground begin to thaw (Figure 2) and the trapped carbon is released into the atmosphere in the form of CO2 and methane – both greenhouse gases.

Figure 2: Permafrost thaw ponds in Hudson Bay Canada (taken from Wikimedia )

Figure 2: Permafrost thaw ponds in Hudson Bay Canada (taken from Wikimedia )

In order to better understand how and when this carbon will be released computer models known as land surface models (LSMs) are used. The estimates of carbon emissions produced by different LSMs vary greatly and many of the models are not yet able to accurately re-produce present day measured soil carbon levels well. A new study by Jafarov and Schaefer (2016), published last month in The Cryosphere, has improved the way frozen organic carbon is represented and simulated in the SiBCASA LSM, producing a simulated present-day soil carbon map (Figure 1) which is much closer to the known soil carbon map of the Northern Hemisphere (NCSCDv2). Both the spatial distribution of carbon and the total amount of simulated permafrost carbon (∼560 Gt C, much closer to the observed value ∼550 Gt C) is improved.

This is a step closer to better understanding permafrost carbon release and the factors that effect it. The authors of this study found they were able to make these improvement to the SiBCASA LSM by improving  simulated thermal dynamics of the soil, improving soil carbon dynamics and initializing the model using NCSCDv2 data.

To find out more check out the full article and remember, it’s not just the ice your eyes can see that is important!

 

 

 

 

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