A Brief Introduction to Projects and Places

With work at WAIS nearly done (only one site left to go!), me and three other POLENETters hopped on a LC-130 and, after boomeranging once and spending an additional night at WAIS, made it back to McMurdo, where we’ll have three to four more weeks of work before returning home. We’ll be using a combination of airplanes and helicopters, but since we are in McMurdo two weeks ahead of schedule, they weren’t exactly prepared for us (understandable), and so we’re on backup priority rather than first priority for a little while. Thus, I’ve got some free time, and it’s just as well, because it occurred to me in the process of writing this blog post that I haven’t described what it is that I’m doing in sufficient detail, and some of the things I’ve said probably haven’t made much sense. So here, while I’m sitting around and not doing much, I’ll endeavor to introduce you to the project I’ve been working on and the places I’ve been spending my time.

POLENET, or the Polar Earth Observing Network, is an internationally collaborative program commenced in 2007 which is dedicated to studying the inner Earth, tectonic plates, climate, and even Earth’s magnetic field using high-precision GPS and seismic sensors located in Earth’s polar regions. The data from these sensors can be used to any number of ends, including measuring deformation of Earth's crust, measuring and predicting ice mass changes (e.g. melt and accumulation of ice on glaciers), and imaging the structure of the inner Earth. All of this can be accomplished simply from knowing the millimeters of displacement of crust over a year, or by recognizing the behaviors of different types of seismic waves as they travel through the Earth.

The project is generally headed up by Ohio State, though there are principal investigators from around the world in order to support its various components, including station groups in Greenland (G-NET, led by Ohio State's Mike Bevis), the Arctic circle regions of Scandinavia, and Antarctica (A-NET, led by Ohio State's Terry Wilson, my adviser). The PIs are typically responsible for logistics and, of course, the science. However, support is necessary when actually designing and constructing the stations themselves. The GPS stations are designed and constructed by engineers from UNAVCO, a non-profit, university-governed research consortium with a pool of very high-tech, very expensive equipment. The seismic stations are the responsibility of PASSCAL (Program for Array Seismic Studies of the Continental Lithosphere), a similarly endowed research group at New Mexico Tech associated with the Incorporated Research Institutions for Seismology (IRIS). Each of these groups, while involved in research all over the globe, has a dedicated polar research team which aids the scientists in achieving their goals. All the groups work closely together - at minimum a budgetary necessity, as many GPS and seismic sites are co-located.

Since I'm working under Terry, I tend to stick to the GPS side of A-NET. Though I've had some experience with seismic sites, and I know something about them since both seismic and GPS groups shared a work tent this year, I'm much more familiar with GPS instrumentation. Stations are typically set on bedrock (though there are a few on ice) and consist of a weather observation device, two or four solar panels, an Iridium antenna, a GPS receiver, 16 to 22 rechargeable 12 volt batteries, and optionally one or two wind turbines, all mounted on a metal frame and anchored to the rock. The GPS antenna is bolted to bedrock on a high point near the support structure. 

The GPS station at Brimstone Peak at the north end of the Transantarctic Mountains. The electronics are housed in/on the frame structure in the foreground. The GPS antenna monument is in the background at left.

The GPS is sensitive enough to detect movement on the scale of millimeters and it transmits data via the Iridium satellite network. Keeping the antenna bolted ensures that it is consistently measuring only the movement of the rock and that it is not being moved by such other forces as wind or snow.

However, just because the GPS can't be moved by it doesn't mean the station can't be affected by the weather. This is where I come in. These stations, even though they transmit automatically, are routinely affected by their respective environments. Solar panels can be shattered by windblown rocks. Connectors can be loosened by annual ice build-up. Sometimes, as is the nature of electronic equipment, things just shut down for no apparent reason. Once, before my time, a battery case exploded. So the stations must be constantly maintained and repaired, and my job is to assist the UNAVCO engineer(s) and PI, if present, in performing this maintenance.

The stations are located, and well-spaced, all over Antarctica. Therefore, we fly to each one, and it is imperative from both a budgetary and logistical standpoint to have bases of operations relatively central to the locations. This year, we had three people stationed at the South Pole, and the rest of the team (14 people, divided between the first and second halves of the season) split their time between the West Antarctic Ice Sheet (WAIS) Divide field camp and the US Antarctic Program (USAP) base of operations at McMurdo Station.

I'm part of the field team for the second half of the season. I arrived mid-December and I'll be here until mid-February. The team for the first half arrived at the end of October and left at the end of December. I spent the first part of my time here out at WAIS, in the middle of the ice sheet. As it's mostly flat and white out there, with GPS stations on nunataks (mountain peaks exposed above the ice), we flew everywhere in fixed-wing aircraft. We used one Twin Otter (De Havilland DHC-6) and one Basler BT-67 (based on the Douglas DC-3) to access our sites. Generally speaking, the Twin Otter is more maneuverable and handy in tight runway situations, and the Basler is able to carry more cargo and more people.

The Basler (left) and Twin Otter (right) parked at WAIS

Mt. Carbone and the Basler - this is typical of the landing conditions for sites accessible from WAIS Divide.

WAIS Divide (1,759 meters in elevation, 1,639 kilometers from McMurdo) was 'settled' in 2005 as part of a deep ice drilling project. Chief among their goals were a) to drill a core in the southern hemisphere comparable to the Greenland cores for comparison of climate conditions, and b) to create a replicate coring technique with which they could extract multiple cores from select periods of time for more in-depth or repeat analysis where original analysis would destroy the sample. When it was built, the drill housing was on the surface of the snow. Unlike other buildings, though, this one had to stay at an absolute elevation so that there was reference for the core depth relative to the 3,465 meter thick ice sheet. So, seven years later...

The main entrance to the drill housing at WAIS Divide

The first goal is an ongoing project, but the second was achieved just after I arrived and it was very exciting. Since most of the camp population (40-50) were drillers, the atmosphere afterward was very jovial, aided by the fact that it was the holiday season. And, well, by the fact that there's not much to do out there.

Life at WAIS was pretty quiet. You knew everyone, everything, and the snow was always clean. Even the heavy machinery (forklifts, etc.) didn't leave any more than a depression. The principal forms of entertainment were movies, card games, cross-country skiing, and sometimes outdoor games, when we were so inclined. When the generators weren't running to power the drill, it was eerily quiet, but it was wonderful hearing the snow fall lightly on my tent as I fell asleep. When the LC-130 came in to deliver cargo or people, it was larger than any single building or machine in camp, except for maybe the drill and its housing.

A late evening juggling circle at WAIS Divide: me, Travis, and Dave (photograph by Jie Chen)

Once we finished with the work at WAIS, we migrated to McMurdo Station, the center of USAP operations. Located on an island(ish) in the Ross Sea, dwarfed by Mts. Erebus (the southernmost active volcano in the world), Terror, and Bird, and opposite the Transantarctic Mountains, McMurdo is an ideal jumping-off point for access to all of our sites in the area. There are a multitude of these because, as I mentioned above, there are mountains, and mountains mean exposed rock and tectonic activity. Mountains also mean lack of runway space, so most of the work out of McMurdo is done via helicopter, more specifically a Bell 212 or a Eurocopter AS350. These versatile machines mean multiple things: 1) we can access more places, and 2) we fly lower. Because McMurdo is at sea level and near the sea, the scenery is quite a change from the flat white of the ice sheet. More scenic, if a little more treacherous, and with more wildlife (note: no polar bears).

A NSF Bell 212 at our Brimstone Peak site - not an ideal place to land an airplane

A small group of emperor penguins shuffles away as the helicopter passes over the Ross Sea ice.

Life in McMurdo is different, to say the least. The population is around 900, the buildings are all permanent, there's constantly a hum of machinery, there are two bars, lots of recreational opportunities, and the ground is mostly undisturbed by snow, at least in town. There are also beds and bedrooms, something which I am struggling to get used to again after sleeping in a tent near freezing for a month, and vehicles with wheels rather than tracks. I'm getting used to it, and I'm grateful for the multitude of things to keep me busy, even if life is a little louder and more impersonal. What's funny here, of course, is that a town of 900 in the states is minuscule. Here, it's the big city, with all the amenities, and there's even a 'next town over': New Zealand's Scott Base, barely a stone's throw away, in case one feels inclined to do some international traveling.

Top: WAIS Divide field camp, with 'tent city' at left and 'town' at right; below: McMurdo Station from Ob Hill

And on that note, I'm going to walk back to my room, brush my teeth with running water over a sink, and head to bed on my real mattress with blankets. Plenty more photos in the coming days. I was overly conservative with my camera at WAIS because I was afraid too much flat and white might be boring. But here there be mountains!