Exploring the FOXX Moulin on the Greenland Ice Sheet

Matt exiting the FOXX Moulin

“Hey David, hope you are doing well! It looks like Will Gadd can't make it to Greenland in October, so I have an opening on the team to explore moulins on the Greenland Ice Sheet. Any chance you might be interested and available for a little under three weeks?”

That was in August. And the answer was yes, of course!

A few weeks and multiple doctor's appointments later to obtain clearance with the National Science Foundation’s arctic program, and after scraping together camping gear rated for the -20s° F (mind you, I live in Texas), I found myself on a flight to Copenhagen. After a bit of sightseeing and sampling the local craft beer, I met up with my friends Jason Gulley and Matt Covington, the two glaciologists whose climate research this trip was in support of. Together, we continued our passage on Air Greenland’s only airbus, headed to Kangerlussuaq, and eventually connecting to Ilulissat.

Ilulissat, a small town in western Greenland by Disko Bay, is home to the Ilulissat Icefjord, a UNESCO World Heritage Site. During our first night there, we were greeted by a spectacular aurora borealis display. A few days were spent assembling gear from both local research stashes and what we had brought with us, and figuring out how to not exceed the weight limit for our helicopter ride onto the ice.

Icebergs in Disko Bay, seen from Ilulissat

Our research site, the FOXX moulin, was about 30 km inland from the coast. Negating any statistical likelihood, the surface temperatures were still above freezing when we arrived, and moving around on the ice even for the shortest distance required donning spikes or crampons on our boots. Fascinated by the ingenuity of the techniques used to stake down our tents, I followed Jason around carrying a running generator while he drilled half-meter deep holes into the ice to drop bamboo sticks into that would serve as tent stakes.

The next morning saw our first approach with rigging gear to the moulin. But what's a moulin, you ask? Essentially a vertical shaft created by melt water on a glacier or body of ice, funneling that water down to the bottom of the glacier, where it creates channels draining into the ocean. Similar in all aspects to how a vertical cave gets formed in bedrock, it just gets carved into the ice in a much shorter time span. Wikipedia has more details, and the illustration you can zoom into on this ESA blog post is also quite good.

Wind blowing recent snow off the ice, past our three personal tents and our mess tent

Soon after our arrival, the temperatures on the ice dropped well below freezing, and the weather varied between sun, snow storms, high winds blowing the snow off the ice again and into our faces, and anything in between. Loud cracks could be heard occasionally at any time of day, reminding us that the body of ice actually moves and is a (slow, but) dynamic beast, as was also illustrated by the fractures that could be seen all over the ice.

All in all, we spent a good week on the ice, exploring the moulin using a mix of mountaineering and caving techniques. Our little tent city was pitched a short hike away from the moulin, and we went on daily trips to survey it for a total of about 80 meters down to the water table. Time was also spent on creating photo and video documentation of the moulin, and illustrating Jason and Matt’s research goals and findings.

Other than being delayed by a day and a half as a result of inclement weather (an eventuality well within the margins of what we were prepared to deal with), our return to civilization was uneventful, and was celebrated with musk ox burgers and pints of Ilulissat’s local micro-brews.

Jason's Instagram account, and Will’s videos and documentation of their earlier expedition onto the ice sheet, offer some stunning images of what it’s like out there

Ice Cave Touristing in Austria

Before attending (and presenting at) the International Congress of Speleology in Brno (Czech Republic) at the end of July, Andrea and I went on a pre-congress excursion to some of the most fantastic ice caves in Austria. (Ice caves, roughly speaking, being caves formed in rock -- typically limestone -- and having perennial ice formations in them.) For a week, Austrian speleologists took us (and a number of other cavers from around the world) on a tour of these marvels in the Austrian Alps.

Beautiful rillenkarst in the Austrian Alps...

We spent most of our time in and around the Dachstein massif of the Northern Calcareous Alps. A good number of the caves we visited were commercially operated show caves, where we either pretty much stuck to the tourist trails and snuck in in between regular guided tours, or in some cases went into the cave after it had closed for the day and veered off trail to follow our guides through non-commercial parts of the cave. These included Dachstein-Mammuthöhle, Dachstein-Rieseneishöhle, and Eisriesenwelt.

Ice crystals in Dachstein-Mammuthöhle.

Our most involved trips went to Schwarzmooskogelhöhle and Eiskogelhöhle. Hiking to the Schneevulkanhalle (snow volcano hall) of Schwarzmooskogelhöhle took us through some beautiful scenery in the Alps, while the hike to Eiskogelhöhle was more straightforward, but required a number of skills inside the cave. Most of our caving trips involved wearing crampons to be able to move around on ice floors.

Rappelling into Hall of the Circe in Eiskogelhöhle.

A bonus caving trip not on the original itinerary took us to Kraushöhle, which did not contain any ice, but stands out as a cave formed by hypogene development. (Meaning, dissolution driven by water from below, rather than water cutting downward into the rock. [PDF]). And our last day took us to one of the eastern-most ice caves in Austria for a quick visit before heading to Brno.

A frozen waterfall has formed a huge ice stalagmite on the floor.

The excursion was extremely well organized and offered a good deal of education on ice caves in general and the genesis and other geological aspects of the particular caves we visited. We made new friends, and learned to enjoy Austrian schnapps -- in particular Zirbenschnaps, made from pine cones. Good times!

Glacier Caves

The day we made it to Gokyo, we spent the afternoon climbing up the lateral moraine to get our first glimpse of the glacier. It was awe-inspiring. The Ngozumpa is a debris-covered glacier. It is fed in its accumulation zone by avalanches, so the snow contains a lot of rocks/boulders of all sizes. When the upper layers of the ice and rock mixture melt, the rocks (debris) is left over and covers the surface of the glacier.

View north onto the Ngozumpa from the lateral moraine at Gokyo.

Lakes of melt water form on the glacier, exposing ice faces. The drainage of those supra-glacial lakes into lower basins on the glacier is the primary cause for the formation of caves in the ice. (Water streaming across the bedrock under the glacier being another, but those were not caves we were expecting to find on this trip due to the depth of the glacier.) After such a drainage event, cave entrances are often visible in the ice faces of drained lake basins, and this is what we were after. (Entering crevasses or moulins in the hopes of finding caves on debris-covered glaciers does not seem to be a good idea, since inevitable, you will be showered in debris when attempting to do so.) Luckily, we were able to identify several potential cave entrances during this first recon trip, and even a convenient way onto the glacier down the steep moraine -- a few years ago, the trail that leads to Dragnag and the Cho La on the other side of the glacier had moved north about two kilometers and now allowed (relatively) easy access to the glacier directly from our lodge in Gokyo.

During our two weeks in Gokyo, we found a total of four caves that we explored, and investigated a number of other entrances that either didn't go anywhere or appeared to dangerous for us wanting to spend time in them:

Jason explaining the basics of glacier cave relevance for GlacierWorks footage.

Cave #1 had a huge keyhole entrance and was maybe 500-600 meters long. It turned out that Jason had already surveyed this cave in 2009. The cave had experienced several modifications since then, including a new branch of passage that led to another entrance in a different (dry) lake basin. We started a re-survey, and Vickie and I learned the particularities of surveying ice caves: setting survey stations with an ice screw and marking them with paper flags, and being particularly accurate with LRUDs (left-right-up-down measurements from the station). In the meantime, Jason and Pati started measuring the scallops on the cave walls that indicate the direction and flow rate of the water through the cave during the drainage event that created the cave. They soon realized that this cave had experienced too many such events to be useful for the model that Jason was looking to create, and we abandoned the survey.

Cave #2 was a small, nicely decorated room in the dry lake basin that could be reached by a trip through Cave #1. Caves #3 and #4 were found toward the end of our stay. #3 started out as a fairly large room with a low ceiling, and a canyon carved through the ice on one side of the room. Below that canyon, more cave passage could be made out, but not reached. At least not with the limited amount of vertical gear that we had made the porters drag up the mountains. (We hadn't bothered, because previous expeditions had not found much in terms of vertically developed caves on the glaciers in the Solukhumbu region.) Cave #4 was a few hundred meters long and fairly well decorated with ice formations. By the time we found it, we had run out of time for a proper survey, though.

Pati admiring drapery.

On our last caving day, we returned to cave #1 to help David Breashears of GlacierWorks, who we had run into a few days earlier, make the cave virtually accessible for education purposes. Mainly by Jason pointing out and explaining relevant features of the cave to support still and video photography taken by GlacierWorks.

To sum it all up: We had a good time, got to go play in some beautiful caves, help an education project, and learn some new things about the Ngozumpa Glacier. And since this was a self-financed trip, we also took the liberty to "tourist" around and spend afternoons climbing Gokyo Ri and hiking out to the Fifth Lake for a view of the intersection between the Gyazumba and Ngozumpa Glaciers. A truly beautiful place.

View from Gokyo Ri at sunset: Everest & Co; southern part of the Ngozumpa; Gokyo; and parts of the Third Lake.

p.s.: Don't try this at home. ;-) While some of the dangers of glacier caving are quite obvious (rocks hitting you while you run in or out of the debris-covered entrance), others (such as, false floors, and cracks in the ice that indicate the potential for a collapse) aren't. Jason spent several hours teaching us what to watch out for...