Discover Magazine: Ecosystem Engineers on ice

In June’s Discover Magazine, science writer Elizabeth Preston explored the mysterious world of icy microbes, focussing on cryoconite. I was lucky enough to chat to Elizabeth several times and provide some photos for the article.

Cover of June's Discover Magazine
Cover of June’s Discover Magazine

Elizabeth described how cryoconite granules form when mineral particles and other debris are “ensnared… in the sticky arms of cyanobacteria” on ice surfaces, having spoken to Prof. Nozomu Takeuchi. I spoke to Elizabeth about the accelerated melting of ice beneath patches of these granules to form cryoconite holes. Krzyztof Zawierucha provided information about the microbes that inhabit the cryoconite holes, including cyanobacteria, heterotrophic bacteria, algae, fungi, protozoans and several invertebrates.

Cryoconite researchers on the Greenland Ice Sheet
Cryoconite researchers on the Greenland Ice Sheet

The article then discussed the ‘biocryomorphology‘ of cryoconite, focussing upon the remarkable process of ice-sculpting to maintain comfortable conditions for microbial activity on the hole floor. Potential impacts of cryoconite as amplifiers of the ice-albedo feedback was then examined, including comments from Andy Hodson (Sheffield).

Tris Irvine-Fynn and I studying cryoconite on the Greenland Ice Sheet (ph. A Edwards)
Tris Irvine-Fynn and I studying cryoconite on the Greenland Ice Sheet (ph. A Edwards)

The article is recommended to anyone looking for a popular science ‘quick-read’ introduction to cryoconite – Elizabeth has presented the basics and some of the complex biotic-abiotic feedbacks in a very accessible and engaging way.

The article is available to view here or in print in June 2016 issue of Discover Magazine.


Biocryomorphic evolution on the Greenland Ice Sheet

Our new paper, “Metabolome induced biocryomorphic evolution promotes carbon fixation in Greenlandic cryoconite holes” came out this week. The main finding is that cryoconite holes can change their shape in three dimensions to maintain comfortable conditions for microbial life – an example of biocryomorphology in action. Here’s a summary of the main points:

  1. Cryoconite holes change their shape and size according to environmental conditions. A mechanism for this, driven by nonuniform arrangement of cryoconite granules or receipt of solar radiation, is presented.
  2. Changes in hole shape are accompanied by changes in metabolic processes in microbial communities on the hole floors
  3. Cryoconite systems tend to evolve towards wide, flat floored shapes where cryoconite granules are spread out and able to photosynthesise more. This means cryoconite holes naturally maintain conditions conducive to capturing carbon.
  4. When these equilibrium states are disturbed, the microbes become stressed, send molecular signals to each other and quickly employ metabolic survival strategies.
  5. A possible mechanism for the migration of cryoconite holes away from shade implies biocryomorphic regulation of hole floor conditions for populations of holes.
Making cryoconite hole measurements with co-author Tris Irvine-Fynn (ph. A Edwards)

This paper indicates the potential for combining ice physical, biogeochemical and molecular (in this case metabolomic) analyses in gaining a mechanistic understanding of Earth’s ice as a ‘living landscape’. Another recent paper by Bagshaw et al (Cardiff Cold Climate) examining cryoconite responses to light stress at the other end of the planet is available here.

Video: What Lives on Ice and Snow?

Here’s a link to Krzysztof Zawierucha’s (Adam Mickiewicz University, Poznan) new film about the biology of ice and snow, including cryoconite holes, snow and ice surfaces. The film clearly shows why Earth’s ice and snow represents a threatened store of biodiversity and illustrates some of the feedbacks between physical and biological processes operating in the cryosphere. See also Krzysztof’s paper in Journal of Zoology for more information about what can live in cryoconite holes specifically (and for more information on cryoconite holes, our cryoconite review).

GRIS15 Diary: Part 3

Thanks to British Society for Geomorphology, Gino Watkins Memorial Fund, Gilchrist Fieldwork Fund, Mount Everest Foundation, Andrew Croft Memorial Fund, Scottish Arctic Club and Gradconsult for supporting this field work. Thanks also to the GRIS15 field team: Ottavia Cavalli, Michael Sweet and Arwyn Edwards

Walking in to the field site (me, Arwyn, Otti). Ph. Mike Sweet
Walking in to the field site (me, Arwyn, Otti). Ph. Mike Sweet

July 8th:

Mike and I went to the field site alone today, as Arwyn and Otti stayed in camp and filtered seemingly endless water samples. At the site, the conditions were much calmer, much more pleasant than on  previous days. I took advantage of the favourable conditions and managed to make extra measurements today. The wind was still occasionally gusty, but we managed to make three drone flights. One was slightly hair-raising and it was only luck that kept the quadcopter from bouncing inelegantly into a supraglacial stream on more than one occasion. Nevertheless, we got some nice footage of the ice surface, imaged our field site and made repeat high resolution imagery of our experimental transect.

Video showing a drone flyover of our field site

Disaster struck on the way back down from the field site though, as Mike’s crampon snapped, leaving him pin-less. Thankfully that occurred past the crevasse field and on relatively flat, solid ice so there was no major drama. On return to camp we arranged that three of us would go to the field site tomorrow, then all back to Kangerlussuaq the day after to find Mike some new crampons and restock food, gas and generator fuel. Back at camp, I made my measurements in the NEP-truck, ate dinner and Arwyn and I stayed up chatting science again, and then it was off to bed ready for a big day tomorrow.

July 9th:

We decided to split the team today, given that we were a pair of crampons short and navigating the crevasses pin-less seemed unwise. Of the four of us, Otti was most willing to stay at camp since she had filtering and sample prep to do that did not require visiting the field site. So Mike, Arwyn and I went up to the field site as a three, while Otti stayed behind. We made quick time getting to the site, and the conditions were perfect. The wind had finally died down, meaning we could work without constantly pinning or weighing equipment down and continually fighting to hold down sheets of paper etc. This increased our productivity hugely – I managed to record more than three times the amount of measurements today than the other days. It really was the perfect glacier field work day – bright and calm and a temperature that was comfortable to work in in just base layers, salopettes and down jackets. We capitalised on the conditions and returned with lots of data.

Working under a beautiful solar corona
Working under a beautiful solar corona

The walk-off was pleasant and we stopped on the way back to appreciate the surroundings. This spot is truly other-worldly – the scale of the ice sheet is quite unlike any other glacial environment and the sense of remoteness at the field site is unique. We discussed the aura of the place – the spooky noises of the winds over the rough ice and through channels and ravines, the sound of cracking ice, of moulins and streams, and the odd, beguiling light. Back at camp I spent a couple of hours taking measurements in the ‘NEP-wagon’ and revising the plans for the rest of the trip. The priority is to get replacement crampons for Mike so that the whole team is field-ready again, so we will have to sacrifice an ice day tomorrow to go back into town. This is a significant journey, so we will combine it with refuelling the truck, restocking food and maybe sneaking in a shower before a big ten day stretch of focussed work on the ice. We convened in the bigger of our tents for whiskey and debriefing before bed.


July 10th:

We began at the usual 06:00 am, but instead of heading to the ice we headed the opposite direction and drove all the way back to Kangerlussuaq. Half the team restocked food while Arwyn and I went to Air Greenland to refuel the truck. Everything went smoothly except for the crampons! However, thank goodness, this was remedied late in the day by the kindly staff at ‘World of Greenland’ who offered up a spare pair. There was also a bit of mucking around trying to find gas for the stove, which packed up this morning, and it ended up costing us an eye-watering £175 to buy enough gas to last the rest of the trip. That was a major blow, but at the end of the day a necessary cost to put us back in business and facilitate time on the ice. Today was an unplanned inconvenience forced by the breakage of both stove and crampons, but unavoidable and probably largely for the best as it put the whole team back in action and we are sufficiently fuelled and fed for the next ten days of uninterrupted field work.

July 11th:

Another day at the field site in clear but windy conditions. The cryoconite holes we are here to study have really changed since we arrived, with different groups showing distinctly different evolutionary trajectories, biogoechemistry and morphology. The diversity of cryoconite entities on the ice surface is remarkable, in their size, shape, cryoconite content, frequency and distribution. Our job here is to test whether these properties follow predictable patterns. It is becoming clear that cryoconite is not just cryoconite – actually the variables controlling the properties of cryoconite granules and cryoconite holes are numerous and interconnected across the micro, meso and macro scales. Hopefully our data will go some way towards shedding some light on these processes.

some of the irregularly shaped 'cryopools' are in stark contrast to the traditional model of cylindrical, pipe-like holes.
The irregularly shaped ‘cryopools’ are in stark contrast to the traditional model of cylindrical, pipe-like holes.
Some cryoconites appear to be complexes formed by merging of mobile holes.
Some cryoconites appear to be complexes formed by merging of mobile holes.
Others seem to have melted out completely and left 'smudges' on the ice surface
Others seem to have melted out completely and left ‘smudges’ on the ice surface

Being Saturday, Arwyn and I insisted upon adhering to an Arctic science tradition – one which originated on the ships of the great polar explorers and was introduced to us by Nick Cox at the NERC base in Ny Alesund… The tradition is formal dinner after a day in the field. So we donned shirts and ties and ate our freeze dried food rations under the British Ensign flag and made a bit of a do. Obviously it was silly given the squalid camp conditions and meagre edibles, but we had three courses – tea, freeze dried curry and a dessert of rye bread and Nutella. Mike was a good sport and humoured us through it and we took a couple of pictures to send to Nick to show him the tradition lives on! We even had a night cap of a shot of whisky and a square of chocolate and toasted the polar greats. Cheers!

A classy formal dinner!
A classy formal dinner!

July 12th

Today we awoke to calm, clear conditions and therefore prioritised drone flying. We hiked in to the field site and used the drone to obtain aerial imagery for creating field maps, completed our transect study, flew some gridded flights to obtain surface images for analysis, and then spent half an hour using it to obtain footage for outreach work. This included attempting a so called ‘sky selfie’ where handheld camera footage is spliced into a gradually rising drone video, spliced into a reversed google earth zoom, creating the illusion of zooming into a cryoconite hole from space… we’ll see if it works when we get home. We also flew several flights over the field site and surrounding area for aesthetic and contextual footage. Afterwards, we nailed the day’s measurements and treated ourselves to watching a movie on Otti’s Ipod before bed.

Otti on ice
Otti on ice

All in all a fun day; except for one major factor. THE MOSQUITOES. The drop in the wind has allowed them to take over. It is mosquito hell. We are having to stay completely covered at all times, and even then they bite through socks and thin trousers. In theory they should die off in ten days or so, but they are making life here rather unpleasant at the moment!

GRIS’15 Diary Part 2

Thanks to British Society for Geomorphology, Gino Watkins Memorial Fund, Gilchrist Fieldwork Fund, Mount Everest Foundation, Andrew Croft Memorial Fund, Scottish Arctic Club and Gradconsult for supporting this field work. Thanks also to the GRIS15 field team: Ottavia Cavalli, Michael Sweet and Arwyn Edwards

The Greenland Ice Sheet (Wikimedia commons)
The Greenland Ice Sheet (Wikimedia commons). Our field site was on the ice in the south-west of Greenland, inland from Sisimiut (marked on the map) near Kangerlussuaq.

5th July.

I awoke very early today, the twenty-four hour sunlight always plays havoc with my sleep for a while. I took the last opportunity to use a shower and packed up the field kit ready to depart from KISS and start the field season proper. The others awoke a little later and we had a group breakfast before loading up the wagon and heading off in the direction of the ice… We spent the morning setting up a camp near the margin of the ice sheet. The temperature difference between here and Kangerlussuaq was very noticeable – we went from sweltering in shorts and t-shirts to wrapping up in base layers and down jackets. The wind was strong and constant, which was partly welcome as during the brief lulls the mosquitos swarmed in thick clouds. Once tents were up and pegged down firmly, we made our way onto the ice in search of a field site. We went in light, leaving science kit at the camp, as this was mainly reconnaissance for tomorrow. We accessed the ice sheet at ‘Point 660’ and walked approximately 4 km to a flat plateau beyond the crevasse field which I had identified last year as a potential site. Here, the ice is much lower gradient and less influenced by the intense cracking and deformation of the ice closer to land, and includes a wide variety of ice types, from patches of dirty snow, flat-ice plains, steep north and south facing slopes and several supraglacial streams. The cryoconite holes here ranged from tens of millimetres to metres in diameter and were present in all kinds of shapes and sizes, with the classic cylindrical ‘pipes’ and ‘buckets’ the most prevalent, but irregular holes and complexes aplenty. In other words, it’s a near-ideal field site for glacier ecology. This site will be our home for the next twelve days. We marked the site on our GPS and hiked back to dry land, excited to start our experiments. Everyone was a bit whacked afterwards, and we noted that after repeating the hike every day for two weeks, we will be either very fit or very tired! We cooked up our freeze dried food, ate it on a picturesque rock ledge near a fierce glacier-fed river, and got an early night, except for Arwyn and I who sat up enjoying a whisky (which required sacrificing two 50 mL falcon tubes as shot glasses) and chatting cryo-bio until late!

The camp on the first day of field measurements
The camp on the first day of field measurements
Arwyn and Otti enjoying the view from 'the kitchen'.
Arwyn and Otti enjoying the view from ‘the kitchen’.

July 6th:

Breakfast was early porridge, again at the riverside. This is a really beautiful spot to eat – we can see the river rising and falling in synchronicity with cycles of melt on the ice sheet (plus a lag) and we can also see a glacier fed lake graudally filling past the moraines. The spot is generally sheltered from the wind, but catches most of the day’s sunshine, so is a comfortable oasis away from the wind, dust, mosquitoes and cold up by our tents. I wonder whether this spot might get submerged as the river swells later in the season though. After shovelling some breakfast, we hot-footed it to the field site and put in a big day’s sampling. The walk-in was quite slow because we were hauling all the science equipment, including the drone, ice corers, drills and biogeochemistry apparatus. My own work was hampered slightly by the strong katabatic winds belting my equipment as I worked, often sending it sliding down towards a nearby supraglacial stream, or making it difficult to work with. We attempted a drone flight, which was also a bit hairy, with the quad-copter strafing uncontrollably in the strong gusts and using a lot of energy trying to right itself against the wind. Nevertheless, good data was obtained and field equipment was stashed away in an ice hollow – this will make the walk in much easier tomorrow. An accidental diversion on retreat landed us in the crevasse field, which had to be negotiated carefully and slowed down our return – we eventually ate at 22.15.

Walking in to the field site
Mike Sweet, Arwyn Edwards and Ottavia Cavalli walking in to the field site

This video illustrates the diversity of topographic and glaciological environs at the field site.

July 7th:

More of the same at the field site today, except that we have hit our stride. Our route from camp to field site is now pretty well known and we cut it down to one hour and got lots of measurements and samples during the day. However, it was really, really cold and extremely windy at the site today, making working very uncomfortable and difficult. The infra-red gas analyser I use to make carbon flux measurements could not maintain sufficient internal temperature and could therefore not be used in situ, and  so I had to revert to decanting the incubated samples into falcon tubes, taking them off the ice entirely and running a make-shift NEP lab in the back of the truck. Not perfect, but needs must, and most importantly the data look good. More tasty dehy’s for tea and a nip of whisky before bed!

On the way to constructing NEP-wagon…!

The DJI Phantom 2 Vision+ quadcopter did a sterling job in the field, but in this video it can be seen catching a fierce gust of wind that sent it off course. Amazingly, it never crashed and was always able to return to us despite the conditions.

One of the team (Mike? Arwyn?) working under spectacular skies at the field site.
One of the team (Mike? Arwyn?) working under spectacular skies at the field site.

GRIS’15 Diary: Part 1

Thanks to British Society for Geomorphology, Gino Watkins Memorial Fund, Mount Everest Foundation, Andrew Croft Memorial Fund, Gilchrist Fieldwork Fund, Scottish Arctic Club and Gradconsult for supporting this field work. Thanks also to the GRIS15 field team: Ottavia Cavalli, Michael Sweet and Arwyn Edwards.

1st July:

Today was varied for team GRIS 15. Mike was attending a conference on water voles (!) while I was giving a talk on research-led teaching at the University of Derby’s annual Learning and Teaching conference. Arwyn and Otti had the worst deal, taking a slow train from Aberystwyth to Derby on the hottest July day on record. The evening, however, was pleasant all around as we chewed over our research plans, redistributed our luggage and ate a final feast in my garden. A few minor dramas were quickly resolved and a few final items added to the Mount Baggage, and we were all tucked in by 12:30!

Getting this lot to Greenland was a bit of a nightmare!
Getting this lot to Greenland was a bit of a nightmare!

2nd July 2015:

An early start today, but an excited GRIS 15 crew were awake and raring to go when the taxi pulled up outside my house at 6am. The obligatory airport tweets were sent out, then it was just a case of grabbing some food and awaiting gate opening at 10:45. We realised at 10:42 that the gate closed at 10:45, so boarding followed a sprint across the terminal. A smooth flight then a whirlwind tour of Copenhagen, including the famous Geological Survey of Denmark (GEUS) and then some dinner before some more strategizing for the second leg of the journey. Looking forward to being back in Kangerlussuaq tomorrow.

A parade in Copenhagen during our stopover!
A parade in Copenhagen during our stopover!

3rd July 2015:

As always, breakfast at the hotel in Copenhagen was spectacularly good – we shovelled some down and hot-footed it over to the airport, checked-in an eye-watering £462 worth of excess baggage and Mike and I flew to Kangerlussuaq. Arwyn and Otti stayed in Copenhagen today, and will follow on tomorrow. We went straight to KISS (Kangerlussuaq International Science Support) to check in and bumped straight into Alun Hubbard (Aberystwyth University) and Jason Box (Dark Snow Project) and their PhD student Johnny Ryan who had been gathering aerial imagery and data from UAVs. In the afternoon, I showed Mike the sights around Kangerlussuaq, including the Watson River which destroyed the bridge in Kangerlussuaq during a period of extremely high melt in summer 2012.  We did a big food shop and met up with our Air Greenland contact providing a car and generator for the next month. Then the task was to assemble and construct some field kit. Unfortunately, our budget could not stretch to a top-of-the-range albedometer for measuring surface reflectance, so I enlisted Mike’s help in building one.

The total cost of this instrument was around £200, almost all of which was accounted for by two Apogee SP-110 pyranometers. The albedometer does not give spectral reflectance values, but it can provide broad-band albedo (300-1100nm) cheaply and effectively, is very easy to use and took only an hour to construct. To use it the multimeter is set to read mV, and the upwards looking pyranometer is connected to the miltimeter using the fixed crocodile clips. The pole is then held out over the desired measurement area. Depending upon the size of the measurement area, the albedometer needs to be held at a particular height. In this study we will be measuring areas with a diameter of 1 metre, for which a height of 0.13m is required. The plumb line is therefore set to 0.13 metres and the albedometer lowered until the plumb line touches the ice. The spirit level is then used to minimise error due to tilt. Once a reading has been taken, the downwards looking pyranometer can be attached to the crocodile clips and a measurement taken. The ratio between the upwards and downwards looking readings gives a measure of surface reflectance (albedo).

Building the albedometer at KISS (ph. M Sweet)
Building the albedometer at KISS (ph. M Sweet)
And testing it out the window! (ph. M Sweet)
And testing it out the window! (ph. M Sweet)

I also whipped up some callipers and marker flags for identifying test holes at the field site while Mike cooked a tasty pasta dinner! Then, as I am prone to doing, I sat up late obsessing over the field plans.

 4th July

Independence Day! Early breakfast and off to pick up the rest of the GRIS 15 team from the airport. Arwyn and Otti arrived in good spirits and we walked them back to KISS with their bags and caught up over lunch. We spent the afternoon hiking to Lake Ferguson and observing some of the beautiful flora and fauna (and getting swarmed by the fierce mosquitos which have plagued us since we arrived). The glacial geomorphology in this region is fascinating.

A late evening view of the dramatic glacial landscape of SW Greenland (ph M Sweet)
A late evening view of the dramatic glacial landscape of SW Greenland (ph M Sweet)

We picked up our vehicle  and took it for a drive as far as the gate before Russell Glacier. Mike got his first glimpse of the ice and was suitably impressed! We are all now very excited to get onto the ice sheet and start working. I’m hopeful that by the end of tomorrow we will have gotten onto the ice sheet, established a camp and selected a suitable field site ready to start taking measurements in earnest the following day.

The calving front of a section of Greenland ice sheet near Kangerlussuaq
The calving front of a section of Greenland ice sheet near Kangerlussuaq

GRIS 15: Final prep

It s now just three days until our Greenland Ice Sheet 2015 (GRIS 15) field season kicks off and we are currently busy with final preparations, packing and tying up loose ends before we leave. I think it is fair to say the team are getting excited – Mike has already packed and is raring to go, I haven’t heard from Arwyn for a couple of days but I assume his kit is still packed from his last polar adventure! Otti and I are busy finishing up our lab work, and I am preparing a Greenland-focussed talk for the annual University of Derby Learning and Teaching Conference on Wednesday afternoon, finishing papers and tying up loose ends from this year’s teaching. It’s all a bit frantic, but soon we will be in the vast open nothing-ness of the ice sheet with nothing but science and adventure on our minds!

Here’s some of the basic info about the trip:


The field site is located relatively close to the margin of the south-west Greenland Ice Sheet, near the town of Kangerlussuaq. We will be accessing the ice from a site known as Point 660 (named in reference to the elevation at that point).

The field site during last year's reconnaissance visit
The field site during last year’s reconnaissance visit on a perfect field-work day
And in slightly less favourable conditions!
And in slightly less favourable conditions!

The Aims:

We aim to learn more about the biotic and abiotic processes that operate on and under the surface of the ice sheet, particularly focussing on aspects of microbial ecology and biogeochemistry. We have designed a suite of novel experiments and activities to undertake on the ice, and will be recording images and video footage for creating outreach and educational materials on our return. We will be having an adventure and learning as much as possible about a weakly understood, beautiful and threatened environment!

Cryoconite holes - generally considered to be the most biodiverse microbial habitats on glacier surfaces and one of the features we will study during GRIS15
Cryoconite holes – generally considered to be the most biodiverse microbial habitats on glacier surfaces and one of the features we will study during GRIS15

The Team:

We are Joseph Cook (Glacier Biogeochemistry, University of Derby), Michael Sweet (Microbiology, University of Derby), Arwyn Edwards (Molecular biology, Aberystwyth University) and Ottavia Cavalli (Microbiology, Aberystwyth University).

Dr's Cook and Edwards working at the field site in 2014
Dr’s Cook and Edwards working at the field site in 2014 (ph. Tris Irvine-Fynn)


The trip has been generously supported by the following organisations:

British Society for Geomorphology

Mount Everest Foundation

Gino Watkins Memorial Fund

Andrew Croft Memorial Fund

Gilchrist Education Fund

Scottish Arctic Club

University of Derby


We are hugely grateful to all of these organisations for their support, please follow the links above to find more information about the great work they do in supporting science, education and adventure.


If you are interested in keeping up with our progress, please return to this website for updates and reports, follow me (@tothepoles), Arwyn (@arwynedwards), Mike (@diseasematters) and Otti (@ottaviacavalli) on twitter, both before, during and after the trip as we will be documenting our progress as often as possible. However, since the field site is rather remote, the frequency of updates will be slightly limited by internet access!