All Systems Go and Mid-season Changeover

There is much progress to report, and lots of exciting science happening at Law Dome. First, all of our systems have now been set up and tested. Sharon and Jose have excavated a beautiful 2m-deep trench, which is now the home of the 4-inch drill, the bandsaw and the freezer.

Tanner and Grant drilling in the trench. Photo: Vas

Tanner and Grant promptly set up the 4” drill, which is what will be used to recover the deep (up to ≈240m) preindustrial ice and the air it contains. Andrew set up the ANSTO bandsaw, which produces fantastic straight cuts on our ice cores.

Andrew testing the ANSTO bandsaw with some 4” core. Photo: Vas

The bandsaw will be used for taking a sliver from one of the 4” cores. This continuous sliver of ice will be analyzed for isotopes of H2O and allow us to determine the ages of the ice layers as well as a more accurate history of snow accumulation rate at the site.

The large ice melter (which we’re using to extract lots of old air from the ice, for measurements of carbon – 14 of carbon monoxide) has been performing extremely well, much better than in all of our tests back home in the lab. We have now completed 5 melt-extractions of air from the large BID cores. These samples will help us to understand how much of the carbon – 14 in our samples is due to production by cosmic rays directly in the ice.

We also did a first test of the large melter system with 4” ice cores, to confirm that the drilling and handling process for these smaller cores is equally clean (it is) and works well (it does).

Vas and Peter with 4” cores stored in a side cave. Photo: David E

Vas pulling the clean sled with 4” cores toward the melter. Photo: David E

Loading ice chips into melter bottom (needed for melting to start quickly). Photo: David E

4” core getting its final cleaning prior to the melt. Photo: David E

The large ice melter full of 4” cores. Photo: Vas

It is hard to believe, but the field season is already over for some of us. Vas, David Etheridge, Richard and Andrew left Law Dome 2 days ago for Casey Station, arriving almost exactly at the same time as Ed and David Thornton, who came via a Basler flight from McMurdo station.

The Challenger tractor at a rest stop on our way back to Casey. Photo: Vas

The team is down to 5 up on the Dome (Sharon, Jose, Tanner, Grant and Peter) – they are currently short-staffed, but are doing their best to keep some of the work going. Fingers crossed that the weather holds and Ed and David Thornton are able to get up to the field site quickly!


First week at Law Dome

It has been one week on Law Dome for the entire team, and what an incredibly productive week it has been.

We arrived in two teams, with an advance group of 5 people heading up the dome November 20th with much of the camp and science cargo. As they battled snow and wind to get all the equipment to our new camp, “DE08-OH,” the rest of us were trapped 130 km away at Casey Station due to bad weather. The three-day blizzard at Casey peaked with winds of 70 knots and a maximum gust of 94 knots!

After a long, snowy, bumpy ride up the ice dome in two tracked Hagglunds, we were all finally united.

The science team on their 10-hour long traverse from Casey to DE08-OH.

Camp living structures shortly after arriving.

Once at camp, everyone was eager to move temperature-sensitive cargo into tents (heroically erected in gale-force wind and blowing snow by the advance team). Making a long story of unpacking boxes short, we went from a 3-day blizzard to having most of our equipment set up in structures 3 days later.

Excitedly unloading science cargo after finally getting to camp.

Ice coring with the US 3” Eclipse drill has progressed to 60 m depth, with firn-air sampling from the surface to capture how the layers of snow trap air as they are compressed into ice.

The Eclipse and firn-air tent.

David Etheridge and Lenneke Jong excited to see the first ice core of the season!

The “ice melter” is safely at home in its melter shelter (or “melta shelta,” depending on your accent). This protective wooden box was put up in 2 days by AAD carpenter Brett, handily assisted by our traverse drivers Juan and Shane from Casey Station.

The science tent and melter shelter, with the large-volume ice extraction “ice melter” inside.

We have fully set up this system and as of December 6th have successfully undertaken our first tests with large ice cores (24 cm diameter, 1 meter long) drilled using the US Blue Ice Drill. The BID is at home in what we call “driller heaven,” a heavenly white tent that should make the operation weatherproof.

A peek inside the Blue Ice Drill tent, where large ice cores are drilled.

The latest project is excavating a trench to house one more drill, the US 4-inch system. The trench is marked out and the snowblowers are getting to work.

The 4-inch drill trench in the process of being marked out. The Blue Ice Drill tent is in the background.

We hope everyone back home is having a great winter. If you’re dealing with snowy weather, we can relate down here on the wet side of Law Dome!

Ready and waiting…

410 words (2-3 minutes)

It’s (for the most part) been a busy two weeks at Casey Station! We now have about half of the team up at Law Dome, moving heavy sleds of equipment from a depot near the dome summit to our now camp–dubbed “DE08-OH.”

LawDome_DE08OHx copy.png

The traverse route up Law Dome. The advance team is currently shuttling equipment between a depot at D-28 and our new camp, DE08-OH. Map data are from the Reference Elevation Map of Antarctica, plotted with QGIS and Quantarctica.

DE08 was an ice core site used by our team member David Etheridge and others to reconstruct past atmospheric CO2 and CH4 (methane) concentrations. This site remains one of the best linkages between modern measurements of atmospheric greenhouse gases, and the ice core record. We are going there again to take advantage of its high snowfall (a fact the advance team may be regretting as they wade through snow…) to shield our samples from too much in-situ Carbon-14 produced by cosmic ray bombardment .

The rest of the team remains at Casey Station, in part to keep the camp population manageable before several tents are erected. We also have more sensitive science equipment back here with us which cannot freeze, so we need warm structures at the site before heading up.

Over the last week or so, we completed our survival training, which was a great combination of hiking out in the sun and snow, watching Adelie penguins, and sleeping out with only the survival gear that we are required to carry whenever we leave station. It’s a minimal setup, including only a “bivy” bag, sleeping bag, and mat to sleep in. But with emergency cold weather clothing, this was still quite comfortable.


A cold, beautiful night at survival camp.


Adelie penguins wallowing in the snow on Shirley Island.


Part of the Shirley Island Adelie penguin colony, including what looks to be a new species: the rock-lier penguin (get it?).

For now, those of us still on station remain ready to drive up Law Dome as soon as possible–hopefully in the next two days. The support from Casey Station has so far been amazing. We are rested, eating too much, and are eager to get to work setting up camp and science equipment at DE08-OH on Law Dome!

Oh, and Happy Thanksgiving! Again, we’re eating plenty of food here…


For another perspective on the project, check out this recent article from Nature News! You can also follow Peter’s posts on Twitter, under the hashtag #LawDome1819.


Settling in and sending the first traverse up the dome

(200 words, 1 minute read)

We have now been at Casey Station for nearly three full days, and have realized that our advance team from the Australian Antarctic Division—Sharon and Jose—have been very busy! They had already prepped two gargantuan sleds, full of camp and science cargo, for traversing up Law Dome (see below).


^ Sharon and Jose with their tractor train to haul up Law Dome.

Yesterday, Monday, November 12, Sharon, Jose and field trainer Anthea headed up the dome with this first load of cargo, which represents a significant portion of the cargo that we need to build our camp more than 100km from station. They are returning from the trip in a few hours.

Any time you arrive at a small Antarctic research station, a significant portion of the first few days goes into getting to know base operations and becoming a safe and helpful part of the community. Casey is a station of about 80 people right now, and in such a small community everyone really needs to pitch in to get all the work done and take care of one another. So far, our experience here has been very warm and friendly, with absolutely spectacular support of our science project! See some photos of the station, below.

^Scenes from Casey, including the station signpost, the main “Red Shed” building, and the field store.

Expedition to Law Dome, Antarctica is underway

(330 words, 1-2 minute read)

After a bit of a blogging hiatus, we’re back in action and on our way to Antarctica! This is Peter writing, at the moment from Hobart, Tasmania. Vas and I are currently waiting for a weather window to fly south to Casey Station, Antarctica with the Australian Antarctic Program!

We are headed to a location called Law Dome, which is a dome of ice on the coast of East Antarctica essentially dead south of Perth, Australia. This site is ideal for the past atmospheric reconstruction we are hoping to do, using carbon-14 of carbon monoxide (14-CO) to learn how atmospheric oxidation has changed through the modern industrial period, from about the year 1880 to present. Here’s a video from the Australian Antarctic Division with a bit of an overview from our Australian project leader, David Etheridge.

It’s been a busy few days for us, flying half-way across the planet, trying not to be jet-lagged, completing cold-weather clothing outfitting, and undertaking many training courses.


Traveling with us are Tanner Kuhl and Grant Boeckmann, ice-core drillers with Ice Drilling Design and Operation. Our training has been thorough and varied… even including chainsaw training with a Tasmanian logger so that we can safely use these tools to build a snow-trench to house one of our ice-core drills!


Currently we are waiting for weather to improve in Antarctica, so we can fly to the Wilkins blue-ice runway and get to Casey. You can see current conditions on their station webcam.


Delays are a part of life in Antarctica, so although we are not surprised we are still eager to get to work preparing our cargo for an overland traverse up to the “DE08” site on the east side of Law Dome.

Stay tuned here for updates from Casey Station and the deep field (as we can get information out). Some of us will be working at Law Dome through January 2019 and won’t be home from Antarctica until mid-to-late February!

Where there’s smoke, there’s CO.

(540 words, ~2-3 minute read)

Over the last few weeks, I (Peter) have been in the lab testing our new ice melting system for extracting ancient air from Antarctic ice in order to study carbon-14 of carbon monoxide (14CO). 14CO can tell us about how the atmosphere oxidizes trace gases and particles out of the atmosphere, something we know little about before modern observations.

We are primarily running these tests to quantify the CO contribution of individual parts of the sampling process. For instance, moving an air sample through transfer pumps adds on the order of 10 ppb CO, while the sample itself begins with less than 100 ppb CO. We want to quantify this “blank” so we can correct our final sample measurements.

To sample the test gases, we use a Picarro cavity-ringdown spectrometer which, briefly, uses laser-light absorption to measure gas concentrations down to parts per billion (see more information from Picarro).

While not running tests, this instrument has been measuring ambient concentrations of trace gases in our laboratory. You can see it in the pictures below, along with the shiny new stainless-steel 14CO melter system.

Over this past Labor Day weekend, I noticed something very interesting in the Picarro data: the concentration of CO in room air was steadily rising from just over 100 parts per billion (ppb, same as 0.1 parts per million on the plot) on September 1st, and nearly doubling to over 200 ppb by September 6th!

CO_AirQuality_LaborDayWeekendtoBy September 7th the concentration had dropped back down to near where it was before the weekend.

What caused this!?

It took me until September 5th to realize the likely culprit: smoke from forest fires burning across the western US and Canada traveling across the continent on the jet stream.

I am originally from Washington State and had been hearing from friends and family about the many active fires and thick smoke and even ash falling in metropolitan areas!

The image below was taken on September 4th, from the NASA Visible Infrared Imaging Radiometer Suite and featured in a NASA Earth Observatory article last week. You can see a pall of smoke crossing the entire United States, reaching to New York and beyond.


Upstate New York air quality data, gathered from AirNow, show a clear rise in the air quality index—indicating moderate/poor air quality—at the same time as the lab background air rising.


Carbon monoxide is produced in fires due to incomplete combustion (not all the way to producing CO2), so where there are large forest fires or other biomass burning events one can expect elevated CO concentrations—which are dangerous for human health if concentrations reach into parts per million. For more information, NASA Earth Observatory in 2015 wrote a great in-depth article about large fires and CO in Indonesia.

Luckily, this rise in background CO didn’t affect the tests I was running—our systems are quite leak-tight by design—but this demonstrates the long-reaching effects of events occurring on the other side of North America!

We live in a very inter-connected world in many ways, and this goes to show how we can detect impacts of events like forest fires even 1,500 miles from where they occur!


*The lab air data in the plots (magenta +) is taken from approximately representative 10-20 minute periods, plotting all measurements to show variability (about one measurement is taken every 2.5 seconds).

Frosty Friday: Glacial Ice vs. Pure Ice

(890 words, about 4 minute read)

Bubble Gas Free Ice

One of these pieces of ice was made in a lab and the other was made in a glacier. Can you guess which is which?

If you guessed that the ice sample on the right came from a glacier, you’re correct! (Bonus question: can you guess how old those bubbles are?) So, why do these two samples look so different, and what do we use them for?

Glacial ice forms on top of a glacier, starting as fluffy snow and becoming compacted as year upon year of snowfall accumulates over time. When the snow first falls, there is a lot of space for air between the individual snow grains. Over time, additional accumulating snow compresses the layers below. Under all that weight, individual snow grains are pushed closer together. These top layers of a glacier are known as firn, the name glaciologists give to multi-year snow. Within the firn, air from the atmosphere can travel freely between snow grains. Firn officially transitions into ice when the spaces between snow grains are no longer interconnected, closing-off air bubbles in the ice and isolating them from the atmosphere. These bubbles are like time capsules, filled with a sample of the atmosphere as it was when they formed. Thousands of years later (up to 800,000), we can dig up these tiny time capsules by drilling ice cores on the Greenland or Antarctic ice sheets. The chemical composition of gases in the bubbles helps us learn about the earth’s atmosphere and how it has changed over past millennia. This is one way that we are able to reconstruct the earth’s climate history (find more info on our lab website).

So, then what’s up with the clear ice sample? Well, that’s a piece of gas-free ice, which we make ourselves in the lab. You’ll probably notice that it’s completely clear – unlike the glacial ice there are no bubbles and unlike the ice cubes in your freezer it’s not cloudy.

When you make ice cubes in your freezer, the water you use has dissolved gases and minerals in it. Ice can be really picky—as it forms it likes to exclude impurities in the water from becoming part of the ice structure. In an ice cube tray, however, the water starts freezing from the outside and moves inward. This happens on all sides, so the impurities are pushed into the middle of the ice cube and get trapped there—this is why you might have noticed the ice cubes in your freezer look cloudy in the middle.

When making gas free ice, we boil purified water in a vacuum-sealed vessel to drive the dissolved gases out of the water without letting any more ambient gases dissolve into the water. Then, we place our container of degassed water in a cold bath, forcing the water to freeze slowly from the bottom up. You can see this setup in the picture below.

GF Ice Setup

As the ice front advances upward, it pushes any remaining impurities above the ice so that they end up in the remaining water or in the headspace of the vessel. After a few days, we have a sample of ice that’s just like our glacial ice samples but without any gases in it! But why go through all of this trouble just for some super clear ice?

The gases that we try to measure in glacial ice samples are present in trace amounts: parts per million for CO2 (carbon dioxide) and parts per billion for CH4 (methane) and CO (carbon monoxide). This means we have to pay attention to small additions from other sources, such as our lab equipment or modern ambient air. We treat our gas-free ice the same way we would a real sample, and can then compare the results to quantify those extra additions (we call this a “blank”).  For example 14C, a radioactive isotope in the gases that we measure, has many useful applications. 14CO2 in particular is produced in the atmosphere by cosmic rays and gets incorporated into the air bubbles trapped in glacial ice. Cosmic rays also produce 14CO2 directly in the ice itself. To be able to use 14CO2 meaningfully to study the atmosphere, we need to quantify the procedural inclusion of 14CO2 at various stages of the ice core collection and analysis process.  We can do this by comparing gas free ice made in the field, gas free ice made in the lab, and glacial ice samples. As we extract and measure air from our ice samples in the lab, the gas free ice acts as an essential diagnostic tool to quantify how well our gas extraction systems are working and to identify the background amount of 14COfrom the system, which we can subtract from our sample measurement.

So, to summarize! Aside from looking really cool, both ice samples are central to the research we do at the Ice Core Lab. We study the atmospheric trace gases trapped in bubbly glacial ice in order to learn about how Earth’s climate works. To accurately interpret this information we manufacture pure gas-free ice, allowing us to double-check that our equipment and instruments don’t dirty up these valuable, untouched time capsules!


Finding your footing and what happens when nature calls…

While we face numerous challenges out here on a glacier in Antarctica, there are two basic tasks that prove to be the most difficult. These are two common activities many of us take for granted back at home. Can you guess what they are?

Looking north from camp over the uneven but gorgeous blue ice surface towards the Asgard Range and Catspaw Glacier.

Looking north from camp over the uneven but gorgeous blue ice surface towards the Asgard Range and Catspaw Glacier.

The first is walking. Yes, walking. We are located in what is called a blue ice zone, where it is so cold and dry that no snowfall accumulates from year to year, and strong winds help to expose the bare glacial ice at our feet. The surface is not smooth and slick like an ice-skating rink, as you might expect. Instead, it is uneven and undulating.

The glacier surface looks as though it is covered by thousands of mini-mountains. These interesting features are formed primarily by the sun, which is why they are known as “sun cups”. The formation of sun cups is also aided by windblown dust and sand particles, which can accumulate in the depressions. These particles are dark in color, and so absorb more heat from the sun—just like how hot you feel when you wear a black shirt on a sunny day. This extra warmth from sand and dust can cause the depressions of the sun cups to deepen.

The uneven, sun cupped surface of Taylor Glacier (size small glove for scale).

The uneven, sun cupped surface of Taylor Glacier (size small glove for scale).

Sand and dust particles blown around in a recent windstorm are accumulating in the sun cups on the surface of Taylor Glacier.

Sand and dust particles blown around in a recent windstorm are accumulating in the sun cups on the surface of Taylor Glacier.

These uneven sun cups make it difficult to walk, but provide entertainment when watching other members of the team move about camp. Everyone tips and teeters around, making slow progress moving from place to place. To help ease our movement around camp, we all wear special treads on our boots. While these help keep us (mostly) upright, movement it is still a slow, tricky endeavor.

An example of the special tread we add to our boots so we can walk more easily around the glacier.

An example of the special tread we add to our boots so we can walk more easily around the glacier.

Knowing how quickly you can move on the ice is critical for planning for the second most challenging activity at Taylor Glacier—making it to our yellow Scott tent, the camp toilet.

Taylor Glacier is located within the McMurdo Dry Valleys Antarctic Specially Managed Area (ASMA). The ASMA provides special environmental protection and requires that we leave no trace, including removing all of our waste.

Because we don’t have running water and also need to ship out all of our waste, our toilet tent looks quite different from any bathroom you might be familiar with. The basics include a bucket, a can and a barrel.

Our Taylor Glacier Scott tent toilet and our UG (urine-grey water) barrels.

Our Taylor Glacier Scott tent toilet and our UG (urine-grey water) barrels.

Inside our yellow Scott tent toilet complete with pee cans, waste buckets, toilet paper and hand sanitizer!

Inside our yellow Scott tent toilet complete with pee cans, waste buckets, toilet paper and hand sanitizer!

We dispose of our liquid in a 55-gallon urine-grey water, or UG, barrel. Solid human waste is collected directly into 5-gallon buckets, which are sealed with a tight-fitting lid once they are full. All of this waste is flown by helicopter to McMurdo Station and much of it is transported on a cargo ship back to the United States where it is processed.

While these details are somewhat unpleasant, they are very necessary to maintain the pristine Antarctic environment—which is of interest to scientists as a relatively undisturbed baseline against which to compare other environments more heavily impacted by human activity.

The stunning view of Stocking Glacier from the Scott tent.

The stunning view of Stocking Glacier from the Scott tent.

Home sweet Taylor Glacier!

Hello from windy Taylor Glacier! For some of us, this marks just two weeks in camp but it already feels like a nice home away from home. So where are we? What is it like? While photographs don’t quite capture the magic of this landscape, here is an attempt to give you a sense of our icy home.

The stunning view from the helicopter looking up Taylor Glacier. Our camp is located about ~15 km (~9 miles) from the terminus, or end, of Taylor Glacier.  Photo Credit: H. Roop

The stunning view from the helicopter looking up Taylor Glacier. Our camp is located about ~15 km (~9 miles) from the terminus, or end, of Taylor Glacier.
Photo Credit: H. Roop

Taylor Glacier is in the McMurdo Dry Valleys. Our camp is located about ~15 km (~9 miles) from the terminus, or end, of Taylor Glacier. Several stunning glaciers surround us while the Kukri and Friis Hills loom over camp. Up valley we can see the Quatermain Mountains and a place called Windy Gully. Our winds come down glacier as they pour off of the East Antarctic Ice Sheet. At the moment, we are all too familiar with these winds as we start our fourth day of strong, relentless wind. We have consistently had wind gusts of over 40 knots (46 mph).

We can generally accomplish all of our work when it is windy but the wind creates a less than optimal sleeping environment and demands extra attention around camp.  Wind can move even the heaviest of items (e.g. sleds, fuel drums) in camp so we have everything strapped down.  Even when it is calm, we check these items frequently to make sure that nothing will blow away when, inevitably, the wind returns. Our sleeping tents are standard camping tents so the wind shakes and rattles us all night. Earplugs are an important part of our sleep kits out here!

Our personal sleep tents are quite cozy but can be loud when the winds howl. This view is looking up glacier towards Windy Gully (upper left). Photo Credit: H. Roop

Our personal sleep tents are quite cozy but can be loud when the winds howl. This view is looking up glacier towards Windy Gully (upper left).
Photo Credit: H. Roop

The rest of camp is made up of our cook tent, two bathroom tents and a range of science tents located near where we are currently drilling with the Blue Ice Drill (BID). Our blue cook tent is where we eat our meals and spend most of our free time, as it is the only space with a heater. In the next post, we will tell you about our yellow Scott tent, the bathroom with one of the best views in the world!

Caption: Home sweet home on Taylor Glacier! Our camp is the perfect size for our current team of eight.  Photo Credit: H. Roop

Caption: Home sweet home on Taylor Glacier! Our camp is the perfect size for our current team of eight.
Photo Credit: H. Roop

Peter and Kathy inside our cook tent. This is the only heated structure in camp (see the heater next to Peter’s feet) so we spend most of our free time here.  Photo Credit: H. Roop

Peter and Kathy inside our cook tent. This is the only heated structure in camp (see the heater next to Peter’s feet) so we spend most of our free time here.
Photo Credit: H. Roop

Despite the wind, we are all still smiling. Everyone is busy collecting and sampling ice cores. Kathy is preparing plenty of hot, delicious food. As always, there is nothing a big cup of hot chocolate can’t fix!

All the best from the Taylor Glacier team!

Mining Ice at Taylor Glacier

Heidi and I left McMurdo Station, known to the locals as Mactown, early in the morning on Friday 7th in an A-star helicopter on a perfect day, flying over the sea ice and Ross Ice Shelf and into the Dry Valleys of the Transantarctic Mountains. Our pilot took us on a scenic route, hovering now and then to point out interesting features and zooming up ice-filled valleys only to swoop over ridges down into the next valley. For a first timer to this area, it was truly majestic and really very difficult to get a true sense of scale. The rocks are mostly granite with dark dolerite intrusions that date from the time when Antarctica separated from Gondwanaland, etched by the wind and cracked by the freezing temperatures into phantasmagorical shapes. Often there appeared to be gargoyles along the ridge lines. It was as though the Elder Ones of the Lovecraft’s Necronomicon had been turned to stone and now stood guarding their icy and forbidden sanctuary. Wonderful stuff in the Mountains of Madness! Our journey culminated in a spectacular flight over Lake Bonney and then Blood Falls before we ascended up the ragged tongue of the Taylor Glacier. Fifteen kilometres from here we spotted the field camp below.

Gargoyles on the ridges of the Transantarctic Mountains of Madness (A.M. Smith).

Gargoyles on the ridges of the Transantarctic Mountains of Madness (A.M. Smith).

Lake Bonney and Taylor Glacier. Blood Falls is just visible below the tongue (A.M. Smith).

Lake Bonney and Taylor Glacier. Blood Falls is just visible below the tongue (A.M. Smith).

Blood Falls (A.M. Smith).

Blood Falls (A.M. Smith).

We landed at about 09:00, towards the end of the working day for the field team of ten who were all working night shifts. Morning in the camp begins at 23:30 with breakfast and the workday begins at 00:30. Lunch is sometime around 06:00 or when you feel hungry and dinner is at 12:00, prepared by the camp manager Kathy. People seek out their beds at 15:00 or so. The reason for these crazy hours is the ice drilling: the drill performs much better under cold, dry conditions and the sun disappears behind Kukri Hills at 01:00, leaving the drill site in shadow. At this high latitude and at this time of the year it never gets dark. Heidi and I had to quickly transition to these unusual hours from the more normal hours we had been keeping at Mactown.

The next few days were a real learning experience for me. I was the driller Jayred’s assistant, learning how to take the large 10” diameter ice cores the Blue Ice Drill (BID) produces. As the cores are brought up, the melting team trim them to size, scraping the outside surface clean and loading the ice melter. It takes one day to drill the 10.5 m of ice core, weighing about 380 kg, which fills the melter. After evacuation and flushing, this ice is melted over a large propane burner to liberate the ancient trapped atmospheric gas within which is then pumped into a sample cylinder. This process is repeated on another two days, sometimes three, to yield sufficient gas for the analyses. This herculean ice mining finally produces samples of CO and CH4 containing just tens of micrograms of carbon. Separate ice samples are also collected and returned to the University of Rochester where CO2 is extracted by sublimation. All these samples ultimately find their way to the Australian Nuclear Science and Technology Organisation (ANSTO) in Sydney, Australia, where they are measured by me for radiocarbon (14C) at ANSTO’s Centre for Accelerator Science.

Near Cavendish Rocks (A.M. Smith).

Near Cavendish Rocks (A.M. Smith).

Sunday was a day off and eight of us headed up glacier by skidoos to Cavendish Rocks, a nunatak around which the Taylor Glacier passes on its long 150 km journey from Taylor Dome. It is also joined by a tributary of the Ferrar Glacier at this point. Where we are, the ice is flowing at 10 m per year towards the sea, which is an incredible 3 cm per day. The ice is folded and faulted in complicated ways. It gets older as you travel down glacier, but also as you travel across glacier. We are camped on 50, 000 year (50 ka) old ice, but from one side of the glacier to the other it ranges from 7 ka in the Holocene through the Last Glacial Maximum (LGM) to 60 ka. Because the ice layers are inclined it also gets older with depth in the glacier, a real three dimensional time puzzle which has been painstakingly mapped out over many field seasons. What makes this area so special is that the ice is sublimed (from solid directly to gas phase without melting) as it is lifted, exposing large amounts of ancient ice near the surface, just what is need to study large scale changes in atmospheric methane during past times. Even with the atom-counting technique of accelerator mass spectrometry (AMS) a tonne of ice or more is needed to produce just the one sample.

On Monday four of the team were scheduled to leave camp and return home via Mactown. The weather had been overcast since Sunday afternoon, with an up-glacier wind carrying more humid air from the coast and the clouds were hanging low on the mountains. This didn’t look too good for the helicopters which can cope with wind but not poor visibility. However, as the morning wore on the wind changed to down-glacier and the day fined up, with impressive stream of snow blowing off the high ridges around, lit by the rising sun in a most dramatic way. The light and weather are constantly changing here and conspire to make it a place of unique beauty and grandeur.

Finally the helicopters arrived, one carrying a sling of cargo and the other a load of ice core boxes. We bade farewell to Vas, Ed, Joe and Berni who climbed aboard and were whisked away. Now we are eight. I sensed a certain freedom in the air now that the three PI’s had left!

Andrew Smith.

The entire Taylor Glacier 2015/16 team (A.M. Smith).

The entire Taylor Glacier 2015/16 team (A.M. Smith).