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

Projecto Espeleológico Sistema Huautla

I spent a week in the state of Oaxaca (southern México) at the end of April, joining the last days of this year's expedition of the Projecto Espeleológico Sistema Huautla (PESH). I knew what I had signed up for – hauling heavy packs out of project caves, surrounded by folks who had spent the last month getting fitter and fitter by going caving every day.

Which is pretty much what happened. I nearly broke myself on the first day, hauling two packs at once while climbing up the "110" (a pit which derives its name from its depth in meters) in the upper parts of Sótano de San Agustín. Followed by a day of shuttling packs from the cave's entrance back to the field house, and a fairly pleasant day surveying and derigging upper passage in La Grieta.

View straight up at night in the entrance of Sótano de San Agustín

The rest of the week was divided between traveling to and from the town of Huautla (and village of San Agustín Zaragoza), and spending time in Huautla and the expedition field house with a bunch of old and new friends.

Looking down the jungle drop into the entrance of San Agustín

Oaxaca City itself, which United flies into, is a great tourist destination and worth a (weekend) visit. I spent a day on my way home touristing around the city and nearby Monte Albán, enjoying lots of great food and sights on México's Labor Day weekend.

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!

Canyons, San Luis Potosí's Deepest Cave, and Food...

I hadn't written yet about the remainder of my Mexico trip, so here it is. I got back from down south about four weeks ago. Thanks to the truck being searched twice at the US side of the border I was ten minutes late for the UT Grotto meeting, but overall I didn't experience any trouble driving through Mexico. So how did I spend the three weeks after the Puebla expedition?

I stayed in Mexico City for a few days at a friend's place who was one of the organizers of the Puebla trip, and enjoyed having some time to decompress, catch up with the Interwebs, go souvenir-shopping downtown, and watch my Mexican friends dance Salsa. ;-) The Metro made getting around easy, and I loved all the different areas downtown with stores that specialized in one thing or another. There were blocks of only hardware stores, audio equipment stores, cell phone repair part shacks, ...

Alexander von Humboldt statue in front of the (ex-?) National Library in Mexico City.

We headed toward Pinal de Amoles in Querétaro for the weekend, intending to go canyoneering. Spending the night in the picturesque (but loud) mining town, our group of a handful hiked from the town center toward the canyons the next morning. After some way-finding we made it to the upper part of the La Barranca canyon and had a blast hiking, rappelling, sliding and jumping into the water pools.

Instead of returning to D.F. (Distrito Federal, aka Mexico City) afterward, I decided to spend a few days in the touristy capital of Querétaro, where I got surprised by plenty of coffee shops with real espresso, and really good microbrews served in a few spots. If anybody is looking to relax in a touristy and safe setting, I recommend it!

Jumping one of the shorter drops of La Barranca.

My last two weeks were spent in San Luis Potosí, staying with the parents of a good caver friend of mine from Austin. I didn't get to do quite as much caving as I had initially hoped, but I know what it's like to have to work during the week and only be able to go caving on the weekend. ;-) So I enjoyed a constant supply of fantastic food cooked by the doña of the house, and spent some time walking around the (quite scenic) old part of town.

However, I also scored an awesome "tourist" trip into what is now San Luis Potosí's deepest cave. I was invited to tag along to pick up some cavers from their long weekend of exploration, and this unexpectedly turned into a day trip down to Camp 2 in the cave (at -500 meters or some such). A very beautiful place!

Cave passage in San Luis Potosí. Glove, umh, for scale.

And I went on another canyoneering trip to Pinal de Amoles with my friend Jean, who came to visit from Austin for a long weekend. This time, we went and played in the lower part of the La Barranca canyon. I have to admit that the water-rich canyons we did in Querétaro are way more fun than the fairly dry ones I had experienced before this trip. ;-)

Jean and I also participated in a successful vertical and self-rescue practice of the local caving club in San Luis Potosí, A.P.M.E. They have access to a steel tower that was originally built for emergency workers to practice, and is just perfect to hang a bunch of ropes off for practicing vertical skills...

Driving the truck back to Austin, and in general driving around in Mexico, was uneventful. Lots of checkpoints, military and police, on the highways in Mexico, but I wasn't hassled once. And my Spanish skills have definitely improved, but are still on a very basic level. ;-)

Tzontzecuiculi Expedition 2013

It took me about half a day to loose my sun glasses in the thicket of brambles, brush, trees, and other random spiky things we encountered on our first day of looking for cave leads at ~2,500 meters elevation in the state of Puebla, Mexico. The first half day of sunshine, that is, after about three of pretty much non-stop heavy rain -- after all, we were in some sort of cloud forest.

Mexican (and Australian ;)) friends invited me to participate in their annual expedition up in the Sierra Negra mountain range, and I excitedly agreed to come out for the full month of the expedition. This expedition features some great Mexican cavers (as well as a few from other places in the world); had previously produced caves over a kilometer deep; and I was keen on spending some time in an environment that would actually force me to improve my pretty much non-existing Spanish.

It turned out to be a great time. For about the first two weeks, the expedition force was comprised of about a dozen cavers, many of them from Mexico City, but also including my good friend Bev from Austin. A going cave lead from the previous year, a cave named Doncella, sadly did not continue past a hundred-and-something meters depth. Much time was spent prospecting for, and checking, new karst features and potential caves in the -- as seen from base camp -- more remote (and higher elevation) parts of Tzontzecuiculi. (I am told that even the locals don't know the meaning of this mountain's name.)

Gathering back together after a day of swarming out high on Tzontzecuiculi to look for caves. A typical exposure of weathered limestone; the brush down in the forest can be much worse to travel in.

Potential cave leads closer to base camp, and to the little town Ocotempa at the base of the mountain, had been "exhausted" in previous years. (To the level of thoroughness one would expect if there are potential exciting leads elsewhere on the mountain that nobody has ever looked at.) And so we cruised (and oftentimes stumbled) over the very weathered and much-exposed epikarst; thrashed (and often cleared our way with machetes) through the undergrowth of the (mostly) pine forest, and in and out of sinkholes; in areas between one and three hours away from base camp.

A propos base camp. Located a couple hundred meters above and few kilometers from the next town, at the location of an old logging site, exists a spot on the mountain that has sufficient flat grounds for a large communal tent structure as well as individuals' personal tents. Scrap wood from the locals' logging operations conveniently helped with the creation of some basic structures, such as a large table and a kitchen area that already existed from previous expeditions. Finding wood for campfires, which were also used to get rid of most of our trash in accordance with local custom, wasn't a problem either.

In camp on a rainy day. The water jugs are already full from collecting rain water off of tarps.

Mules were rented to transport gear and food up (and at the end, down) the mountain to and from our trucks. A little stream is close by to collect water, although (in my opinion) the rain running off of tarps that we collected during some large rain events we experienced throughout the expedition tasted significantly better. ;-) Last but not least, there even is a hill with (albeit very, very slow) cell phone / Internet access within 10 minutes hiking distance. Quite plush. :-)

In the last two weeks of the expedition, with a caver force slowly being reduced to five of us for the final week, efforts started to concentrate on mainly two promising leads, one on the east and one on the west side of the mountain:

A cave referred to as TT103 (based on its entry in the expedition's cave/karst feature register) that had been found -- but not explored -- last year and is about half an hour away from Doncella. This allowed us to use the bivvy setup that had been established earlier at the Doncella entrance, allowing a team of two or three cavers to spend the night close to the cave -- in sleeping bags under a tarp spanned between trees -- rather than spending about four hours a day just for the hike from and to base camp. Plus, a trail had been established to Doncella previously, making travel not easy, but at least easier. TT103 was the first cave on this expedition to exceed a depth of 200 meters, and in the end was pushed to slightly more than 250 meters. It awaits more exploration...

TTW28 was found this year on the west side of the mountain, at almost 2,700 meters elevation, after a good day or so was spent early on to establish and cut a trail to that side of the mountain for easier travel to that prospecting area. After a hundred-and-something meters of depth the cave required a bit of chiseling to enlarge a constriction, but then continued well. Since we had only one set of bivvy equipment, which was in use at Doncella, this eventually involved long day trips from base camp as the depth of the cave continued to grow. This cave was left going at the end of the expedition as well, with an exciting pit half-way rigged.

In the entrance of TT103. Cleaning eroded limestone off the wall in order to place a bolt anchor for the rope.

Many other "lesser" caves were found during the expedition, some going to about 50 or 70 meters deep, but were quickly abandoned when it turned out that they didn't continue past that. (Looking at the elevation of the resurgence that is associated with the karst up on the mountain, a depth potential of about 2 km exists if one can only find the right cave. ;-))

All in all, I enjoyed this expedition a lot and learned many things. For one, obviously, a decent set of caving-related vocabulary in Spanish; although -- as usual -- it takes me forever to commit new words to my brain's memory. But also a good amount of new (to me) caving techniques and tricks, heavily influenced by the European style of caving. Rigging with 8 mm rope and knots I hadn't known before; using abrasion-resistant and lightweight dyneema cord instead of webbing; having universal ways of charging all types of batteries from a 12V battery fueled by solar panels; ...

And not least, this may well have been one of the most socially developed (in a positive sense) expeditions I have been on. A number of friends who mostly know each other fairly well (and yet were extremely welcoming to me as a new group member and not-much-Spanish speaker); sharing of not just food, but all sorts of gear, including each other's vertical kits and caving suits (who wants to drag their many kilograms of personal gear to another part of the mountain every day? ;-)); and temporary contribution of individual rigging gear for group use by each individual instead of commercial sponsorships or huge expedition fees. (In addition to a number of things that have been amassed over the years in a group stash, everybody brings some rope, rigging gear, ...) Etc.

Another month of my life well spent! :-)

Exiting a cave from where it bottomed out. You can see the daylight and vegetation in the entrance.

Caving in South China - Hong Meigui's Spring Festival Expedition

I went to participate in this year's Spring Festival (aka Chinese New Year) expedition of the Hong Meigui Cave Exploration Society. The objectives sounded exciting: Establish camp in (and push leads off of) Da Luo Dang Tiankeng. In particular, explore a multiple-seconds drop (when throwing down a rock and listening for it to hit the bottom) downstream, where the explorers had turned around during a previous expedition, since they didn't want to take their chances to get flushed down it in the rainy season.

View of camp, and into Da Luo Dang Tiankeng.

The tiankeng (Chinese for "sky hole", "heaven pit") is most easily accessed by cavers through the San Wang Dong system, rather than climbing to it on the surface and dropping into it. This involves a 2-6 hour trip (depending on amount of gear to carry and other factors), mostly through walking passage and some borehole, but with a few shorter vertical drops, smaller spots, and climbs on the way. We established camp in the passage that opens up into the tiankeng after a few dozen meters; the floor is relatively flat, and there was evidence of previous human use in the form of two cooking hearths and a little rock wall to protect against the wind, presumably created by miners a little while ago. We brought custom-made, floor-less, light-weight tents with us that were attached with strings to bolts and features in the walls, in order to protect ourselves from the draft when in our sleeping bags and capture some of our body heat -- a common technique when camping in drafty cave passage.

It was funny to stay in a cave camp that would see daylight during the day. And cold, since we had direct access to the surface climate. (As opposed to the usual 12 degrees Celsius that is typical for the caves in the area.) Camp was maintained for ten nights total, Angela being the only one down there for the full time without getting a surface break. Erin almost made the record, but then her and I were faster than planned on the de-tackling day before breaking down camp for good, and managed to drag a load of gear out of the cave all the way to the surface, earning ourselves a break from the freeze-dried dinners underground and going back to sleep one more night in the cave. Early on in the expedition, Madphil and I had spent a day bouncing to the surface and back to get more rigging gear, our supplies of rope being exhausted much sooner than expected. (Our trip lead to the entertaining question of what a reverse call-out time should look like: Send a rescue party to the surface if we aren't back in cave camp by the next morning? ;-)) And to add yet another surface trip for myself, Devra and I joined the team leaving the cave during the first wave of de-rigging and departure from the expedition. I spent a surface day to rebook flights, and then solo-caved back in to bring food supplies for the remaining days.

View up in Da Luo Dang Tiankeng.

Once derigged, all the gear was transported back from its / our temporary home in the village of Er Wang Dong (Houping area) back to Tongzi, and us remaining expedition members spent multiple days cleaning gear and wrapping up things. The accomplishments of our group of (at peak times) eight cavers during not quite two weeks of caving included:

• Exploring the downstream passage, spear-headed by Carl. The ~ 80 meter pit was rigged, and passage was explored until the remaining leads were still promising, but require better preparedness for cold, wet caving.
• Madphil and Rob spent most of the days aid-climbing upward, using a total of not quite a hundred bolts. Their noses directed them straight toward Tian Ping Miao Tiankeng, a (relatively!) smallish sinkhole known from surface topography and now connected into the system. Sadly, no interesting leads were found off of it.
• Erin climbed up a steep slope in Da Luo Dang Tiankeng in order to determine its extensions, and to her surprise found passage that showed evidence of miners (nitrate, maybe?) spending time up there, processing stuff, and having built a system to traverse a series of rifts as evidenced by wooden stemples and ladders apparently used to ease traveling at a certain elevation in the rifts. We spent multiple days exploring that passage without finding an obvious way on - when we ran into climbing leads in the last days, the only hammer drill left in camp conked out at the first attempt of using it.
• Beardy and I got a good amount of decent photos on the trip, I think. I wish I had brought my second slave flash unit...

Upward, by means of hammer drill.

I enjoyed this trip a lot, it was a great mixture out of new and old caving friends, skills, and personalities. It also was a good opportunity to get me comfortable again with (and remember where my limits are when it comes to) slightly more involved expedition caving - traversing along fixed lines, (free) climbing relatively exposed climbs, etc. I'm ready for the next one! :-)

Cave Survey Guidelines, and Other Things

A few years ago, Bev and I wrote a set of notes for new cavers on how to be a (both effective and efficient) part of a survey team. Basically, how to read instruments, set stations, communicate with the sketcher, etc. Which, really, is a good (the best?) way to get involved with and invited to caving projects, until you progress from there to learning how to sketch and draft maps, amongst other things.

David surveying in Punkin Cave, a couple of years ago... ;-)

While surveying in Quintana Roo over the holidays, I had time to reflect on this and also to collect some extremely useful comments from the fellow cavers who were around. I've finally managed to consolidate all this and publish an update on our Grotto web page:

Cave Survey - Using Tape / Disto and Instruments (PDF version)

In other news that will be less interesting to the general public, I'm currently spending a few weeks in Texas before heading to China for an expedition over Spring Festival. Besides participating in a cave digging project in Austin, (which is surprisingly fun, I have to admit as somebody who doesn't dig much in caves,) we made some progress in my project cave O-9 Well last weekend.

Line plot of survey data from Walls (a cave survey database application). 100 meter-grid. The orange stuff was added to the survey last Saturday.

Nine Texas cavers headed out west to continue the re-survey of the cave in three teams. All in all, we surveyed over 500 meters of fairly small, muddy, and wet passage. It took us longer than I had expected, too. But, all the main passage has now been re-surveyed, and what's left to do is to follow a side lead to where it's likely to end under a plugged sinkhole (the leg taking off to the north on the line plot above). And, of course, for me to draft the final map of the cave based on the survey data and sketches -- the primary reason for starting the project.

Apart from that, I'm dragging behind with accomplishing the various things on my to-do list. Something that hasn't changed since I left my job. Ah well.

Quintana Roo Cave Mapping Project

Over the holidays, Andrea and I went to Quintana Roo (in México, it's the state sharing a peninsula with the Yucatán) for ten days. Our aim was to help with the survey of dry caves in the region, conducted by the Quintana Roo Cave Mapping Project. (Dry caves in this context mean they aren't underwater caves that require cave diving -- there may still be streams and lakes.) The particular objective of this trip was to create a high-quality re-survey of a cave system that is also being used by a natural reserve tour operator, just south of Playa del Carmen. The resulting data will then be used to create a new map for the cave.

It was both plush and productive caving. All in all, our group surveyed over 27 km of cave on this trip. I personally contributed about 2 km of sketching over 9 caving days -- some in chest-high water, but most of it looping through a huge breakdown room with multiple chambers created by the breakdown. Frequently running out of pages made my brain hurt sometimes, though. (See photos of pages of my survey book. They will be replaced with better copies soon.)

A page from my survey book, showing the south-east corner of a large breakdown room we surveyed.

Survey notes. Distance between survey stations, as well as azimuth and inclination readings.

Since the caves are all located in the jungle and close to the surface, they have a rich fauna. Amongst other creatures, we frequently saw amblypygids, tarantulas, small catfish, cave-adapted fish, cave crickets, etc.

Amblypygid sensing around for prey. No scale, sadly, but there were some pretty big ones in the caves.

Our group of 20+ cavers mostly camped on the same property in the jungle that our main cave entrances were located on. We had flush toilets, showers, a pool, and daily breakfast and dinner were cooked for us -- couldn't be better! In between, we took a day off to visit the Maya ruins in Cobá and go snorkeling in the Gran Cenote outside of Tulum. Traveling from Texas to our camp was fairly straightforward, too -- direct flights between Austin and Cancún. Fun times all around.

Cutting (not quite ripe) coconuts to mix their juice with rum on Christmas Eve. :-)

I didn't take many pictures, and the few I took are of pretty low quality, but for completeness, the public photos of this trip can be found here on SmugMug.

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...