Our series of Editors’ Vox to discover what AGU journal editors do when they’re not reviewing manuscripts continues with the Editor-in-Chief of JGR: Earth Surface, Bryn Hubbard. We asked him about his recent field research on the flanks of Mount Everest.
Where did you go for your most recent field research?
With most of my previous field research in the polar regions, it was something of a departure for me to pack my bags in late spring for a trip to the Himalaya.
My destination was Nepal’s Khumbu Glacier, specifically the 10-kilometer long debris-covered tongue of the glacier whose upper reaches flow off the flank of Mount Everest itself and provide access to climbers.
Despite almost a year of planning and preparation, there remained three fairly significant questions before departing: would the team be able to reach the site, would the equipment work when we got there, and would we able to collect the data we wanted. Some of these uncertainties were captured in the media coverage before we left including a BBC news article (including two videos).
How was your journey to get there?
Flying into hot and busy Kathmandu was quite different from my usual field destinations such as Greenland or Antarctica characterized by open spaces and sub-freezing temperatures. But that was just the start…
Selecting an aircraft for our internal flight from Kathmandu to Lukla in the Himalayan foothills was a somewhat chaotic activity involving seemingly randomly-distributed piles of trekking and camping gear, a great deal of arm waving and shouting, and the scene made all the more surreal by the presence of inquisitive (and acquisitive) monkeys within the terminal.
If that experience was eye-opening, landing at Lukla airstrip (2,850 meters above sea level) was rather more eye-closing. The landing strip extends at a downward slope of more than 10 degrees towards to a vertical mountainside. I had somehow omitted to read up on this aspect of the trip beforehand, although I did suspect something may be out of the ordinary when the passenger next to me began to clutch their hands and pray loudly five minutes before landing.
Thankfully we landed safely and, after a quick breakfast, began our eight-day trek to Khumbu Glacier. I remember the first day as being relatively straightforward and filled with light-hearted banter, due in large part to the low(ish) elevation, a largely downhill route, and breathing dust-free air.
The next seven days, however, were not. The scenery was unquestionably spectacular, our pack bags were carried by porters, and we had overnight stays at convivial guesthouses, but the trek was something of a physical challenge for one who is used to snow scootering around flat ice shelves just a few meters above sea level.
Suffice it to say that we arrived nine days later, in a far from decent shape but fundamentally intact, at our first camp on the glacier a couple of hundreds of metres up-flow of Khumbu’s terminus (see image at top).
What was the focus of your scientific research?
Almost nothing is known about the interior of high-altitude, debris-covered glaciers. The reason for this lack of information is straightforward: working on such glaciers at about 5 kilometers above sea level, to say nothing of accessing their interior, is logistically difficult.
With my experience of using pressurized hot water to drill boreholes on ice masses – albeit normally in polar regions – Duncan Quincey of the University of Leeds brought me in to the EverDrill project. Together with Evan Miles, a Post-Doctoral Research Assistant, and PhD student Katie Miles, our task was to drill boreholes at three sites along Khumbu’s tongue and to install probes within those holes designed to measure the internal temperature, deformation, and structure of the glacier.
How did your drilling equipment reach the site?
Some of the equipment was slung by helicopter to the site and the rest carried by porters. En route it experienced various minor ailments ranging from surface scratches and ruptured pipes to sheared switches and major dents. This is to say nothing of a petrol motor having been filled with diesel, and then emptied by inverting the entire unit rather than via its drain plug. After a year of planning and more than a week’s trek to get there, we wondered whether we would be able to do anything that we had planned.
What were the challenges of operating the equipment at high altitude?
Our hot water drill was adapted from a car wash and all our apparatus was run using combustion motors. Although we had tested them in Kathmandu, we were now about three-and-a-half kilometers higher in altitude and we simply didn’t know if they would operate at that elevation.
Of the four motors that we needed to run, only one – the large generator with the initially ruptured fuel feed and broken recoil start – was running at the end of day one. By the end of day two this had been joined by the second generator and the water pump, leaving only the somewhat recalcitrant high-pressure-pump motor. Our boreholes were not going to get too far without this motor running as drilling by pressurised hot water requires, well, hot water under pressure.
By day three, having dismantled and tested almost every component of the motor, involving helpful – but ultimately unfruitful – voluntary contributions from at least 15 passers-by, we reassembled the motor, attempted to start it (unsuccessfully), gave it one final kick and set off to clear our minds by exploring the glacier.
On our way back to camp some hours later, reports reached us that the motor was finally running. Our enterprising (and invaluable) field guide had pulled the recoil start repeatedly for a full 15 minutes until the motor block had warmed up, at which point it fired and ran. Throughout the subsequent research, the motor never needed more than half a dozen pulls on the recoil start, which left me sagging and gasping for air. To have done this continually for 15 minutes (not to forget, at an elevation of 5,000 meters) not only probably saved the project but represented a somewhat superhuman effort.
How did the drilling of boreholes go?
With all our motors eventually operational in Khumbu’s rarefied atmosphere, although spluttering and burning far from cleanly, we didn’t know if we’d be able to actually drill the boreholes.
Knowing almost nothing about the internal structure or temperature of a glacier does not help in planning the most effective means of gaining access to that interior. For example, various experts had conversationally predicted that the ice would be so cold, flowing down from about 7,000 meters off Everest itself, that our drilling rig would simply not be able to supply the energy to melt a borehole. Others had suggested that the glacier would be so infused with debris that the drill tip, which delivers the hot pressurised water as a millimetre-diameter high-pressure jet, would not be able to penetrate any useful distance.
With these warnings foremost in our minds, we began drilling at our first site, through thin ice near the glacier’s terminus, advancing slowly and carefully at about 0.5 meters per minute.
We managed to create a first borehole to about 35 meters below the surface. Since we were unsure whether we had hit the bed or an internal debris layer, we subsequently drilled a second borehole to about 45 meters depth.
Not knowing the internal temperature of the glacier – and hence fearing that it may freeze shut within hours – we immediately logged the longer borehole by optical televiewer camera and installed along it strings of thermistors and accelerometers. This all went surprisingly smoothly and, with data being logged automatically every 5 minutes, that evening was accompanied by much celebration.
The second drilling site, located about 4 kilometers upglacier, proved more difficult due to debris within the ice and required the drilling of ten boreholes to a maximum depth of almost 30 meters. On the third site, near Everest Base Camp at an elevation of about 5,200 meters above sea level, proved more successful. We drilled a single borehole uninterrupted to a depth of about 150 meters over three days.
Despite the difficulties, we managed to successfully drill, log and instrument medium-length boreholes at a high elevation on a debris-covered glacier for the first time. Some of the team will return later this year to monitor the instrumentation and download ice velocity and borehole data. A second drilling campaign is planned for spring 2018.
I’ve not even begun to tell you about what we hope the data collected from the boreholes will reveal, how we will use it in a model to predict glacier evolution, and how resulting forecasts could be of wider use to policy-makers (find out more about the EverDrill project).
As scientists, our peers see the outputs of our work in terms of data, analysis and results presented in scholarly journal articles. But sometimes it’s worth drawing attention to the hard work behind the scenes that results in a 10,000-word manuscript.
We set out to access something fairly inaccessible and measure something about which very little was known. Despite much planning, we began our fieldtrip with a range of uncertainties, practical challenges and physical hurdles.
Thankfully, in this instance, we succeeded and are now in a position to tell the tale and soon report the results. For now though, I am back to the safer task of reviewing manuscripts for JGR: Earth Surface…