Around the time the Princess Elisabeth station crew were unloading the Mary Arctica, a 70 km2 iceberg calved off of the King Baudouin Ice Shelf, just 40 km away from Breid Bay.
I spy with my satellite eye
Over the past weekend International Polar Foundation Vice-President Nighat Amin spotted an interesting event: on January 25th, it appears that a 70 km2 iceberg broke away from the end of the King Bauduoin Ice Shelf - only 40 km to the east of Breid Bay, where the station crew had been unloading the Mary Arctica around the same time.
According to Université Libre de Bruxelles (ULB) glaciologist Frank Pattyn, who has been studying the King Baudouin Ice Shelf for several years, and was on the ice shelf with a team of fellow glaciologists from the ULB this past November and December, the 12 kilometre-long and 6 kilometre-wide iceberg may have already started to break away from the ice shelf before January 25th, and only started to drift away on that particular day. Satellite imagery from the end of 2014 shows a large fissure in the ice shelf where the iceberg eventually broke off.
Calving is natural
The calving of icebergs (the process by which ice breaks away from the end of an ice shelf or glacier) is a natural phenomenon whereby ice flowing off of a continental ice sheet (such as those in Antarctica and Greenland) is lost to the ocean. An ice shelf is a floating platform of ice that is an extension of ice flowing off of the continental ice sheet out towards the ocean. Ice periodically calves off the seaward end of an ice shelf and is replaced by ice flowing off from the continent behind it.
The King Bauouin Ice Shelf hasn’t shed ice since the 1960s, according to Pattyn, so the calving event has been a rare event to witness. “We’ve been studying this ice shelf for so long,” Pattyn remarked. “so it’s interesting to finally see something happen!”
While the King Baudouin Ice Shelf doesn’t lose ice very often, the fact that it has recently isn’t a sign that the ice shelf is weakening or in iminent danger of collapse. Pattyn explained that an ice shelf can only grow so far - up to the continental shelf break on the coast of Antarctica, where the sea floor dramatically drops - before part of it inevitably calves off. “It is very difficult for an ice shelf to grow beyond that limit,” explained Pattyn.
Pattyn’s colleague at the ULB, glaciologist Reinhard Drews (a past laureate of the InBev-Baillet Latour Antarctica Fellowship), also added that according to the data they have, the velocity at which the ice in the ice shelf has been flowing towards the ocean hasn't increased dramatically over the past several decades. This is in stark contrast to the dramatic increase in ice flow velocity seen in places like Pine Island Glacier in West Antarctica, which is rapidly losing ice to the ocean. Whether the King Baudouin Ice Shelf remains stable in the coming decades, however, will depend on whether climate warming starts to affect the part of East Antarctica where it sits, according to Drews.
I want to break free
It’s impossible to know exactly what caused the iceberg to break free. The Princess Elisabeth station crew who had taken part in the unloading at the coast hypothesized that the swell caused by a storm that disrupted the unloading of the Mary Arctica might have been what dislodged the iceberg from the ice shelf. Drews commented that the swell could be behind the dislodging of the iceberg. However he explained that there is “no way of knowing for sure” that the swell is what finally caused it to break free.
Whatever provoked it to go, Pattyn said that he was happy not to have been on the part of the ice shelf that broke off. The GPS stations he and his colleagues set up on the ice shelf for the IceCon project are now much closer to the sea than they were a few weeks ago!
Jos Van Hemelrijck recounts the journey home to the Princess Elisabeth station form the coast. On the way, the team gets to test out the new customised Toyota Hiluxes.
A long journey home
Now we’re back at the Princess Elisabeth station and glad to be here. Our bones are still a bit sore after a bumpy, 20-hour trip with no sleep. We were grateful for the hot showers and the soft pillows of the station! Princess Elisabeth feels very much like “home” to us after spending four days on the ice.
The return trip from the coast went well. One of the Prinoth tractors had to be repaired along the way. Fibrous debris had partially blocked its fuel lines. But it was no big deal for our seasoned mechanics. Kristof had the snow tractor back in service and running within 20 minutes.
Two of the Lehman sledges in the convoy were loaded with wooden beams and long rafters that will be used for finishing the new garages. They were very heavy - 12 tons per sledge - and oversized on top of that. The overhanging beams made it impossible to hook the sledge up to the preceding one (the pulling ring normally locks onto a hook). Instead, these sledges had to be dragged with a long rope at the end of the train.
Ilir and David drove the Prinoth with the heaviest load. On two different occasions when going up a steep slope, their train got bogged down in the snow. The tracks of their tractor were digging deeper and deeper, unable to get any traction on the snow. Kristof, who was bringing up the rear, had to unhook his Prinoth to come to the rescue and drag them up the hill.
Testing out the Hiluxes
The two Toyota Hiluxes - our new toys - had no trouble at all driving up the hills at full clip. They were able to maintain speeds of 40 kilometres an hour and more, even over rough patches of snow. If you compare that to the usual 10 to 12 kilometres an hour the Prinoths can do, it’s easy to understand that these vehicles will make a big difference on future field trips.
It is odd, however, to see four triangular tracks on a vehicle you would expect to find on the roads back home. They’ve been fitted with all sorts of amenities like a hi-fi stereo and so on. The warning beeps if you forgot to put on your safety belt – including the passengers’ - was bit of a nuisance. We’ll get rid of that I’m sure.
One thing that surprised me was the fuel consumption of these vehicles in Antarctica. A conventional 4 x 4 would need 11 or 12 litres per 100 kilometres on the road back home. I expected the track-fitted Hiluxes would use more fuel in an Antarctica environment. Driving in these Antarctic conditions cannot be compared to anything back home. But I was surprised to learn that we emptied the fuel tank of one of the Hiluxes before reaching the station, after a mere 200 kilometres!
Kristof Soete, who converted the Hiluxes, assured me that some fine tuning will improve fuel efficiency. “When you consider that even a one-man snow mobile uses 20 litres for every 100 kilometres and a Prinoth needs 50 litres of jet fuel to cover 12 kilometres in an hour," explained Kristof, "you realise that these Hiluxes are really a great asset for our transport needs.”
It's good to be back!
At the station we were welcomed by our six friends who stayed at PEA during our four days of absence. Carpenters Jacques Touchette and Chick Blaise were more than happy to see the long-awaited beams they needed to continue building the garages - and to have some company again. While we were gone, there were only six people at the station - which made it seem quite empty following the departure of the German scientists.
We learned that during our absence, Chick had broken a bone in his hand when he slipped on an icy spot in the garage. Doctor Richon had to fit him with a plaster cast, but he was back on the job. “No problem!” he said. “It’s my left hand. I’m right-handed anyway.”
Before we went to bed, we all joined the cooks David and Riet to transfer all the food we brought to the station’s fridge and freezer. We marvelled at the fresh eggs (imagine, we can have an omelette again!) mangos, grapes, frozen fillets of steak and fish. We even noticed a box of foie gras. But that, we heard, was for next years’ Christmas dinner. These supplies must last until the arrival of the next ship - in January next year, hopefully.
The Princess Elisabeth team heads to Breid Bay to meet the Mary Arctica to unload its cargo and transport it back to the station. A rough sea complicated things, however ...
A change of plan
We set off from Princess Elisabeth station at 10 pm on Thursday January 22nd with four snow tractors pulling three or four ledges each. The Mary Arctica, the Danish ice-class ship that had our supplies loaded onto it in Zeebrugge back in December had been held up for several days off a ship mooring site known down here as “Five Degrees East” - the point on the coast of East Antarctica at 5°E longitude.
The ship was scheduled to drop off supplies and fuel at 5°E for the Norwegian Troll station first before meeting us. Unfortunately, access to the coast there had been blocked by a massive pile-up of sea ice, with no sign of ice conditions improving soon.
Meanwhile, Breid Bay was completely free of sea ice, and easily navigable. Alain Hubert had been down to the coast on skidoo to check on ice conditions more than a week ago. GG, at IPF headquarters in Brussels, had in the meantime sent detailed satellite pictures of the ice situation in our area to the captain of he Mary Arctica.
With ice conditions much more favourable at Breid Bay, and with the clock ticking, the captain eventually decided to come to Breid Bay and unload our supplies first, in the hopes that sea ice conditions at 5°E would improve by the time he’d finished with us.
We were told to expect the Mary Arctica at Breid Bay the evening of Friday, January 23rd.
We’ve got a great big convoy
What an impressive sight we were, a convoy thundering towards the coast at Breid Bay, 200 kilometres to the north of the station! I rode with Alain in the lead Prinoth snow tractor for the 20-hour drive.
At some point, I took over steering the tractor for a couple of hours to give Alain a chance to rest. The Prinoths are very powerful machines, but they must be steered very delicately with a small toy-like wheel. It seemed unfitting for such a large and powerful machine to have such a small steering device.
Since we were the lead tractor in the convoy, we had to navigate using only GPS. No old tracks to follow. The snowdrift had already covered Alain’s skidoo tracks from more than a week ago.
Arriving at Breid Bay
The Mary Arctica had arrived shortly before us. Her bright, red hull was nestled close to the edge of the ice shelf.
The first first thing we did upon arrival was to meet with the Danish crew, who invited us on board for a welcoming meal. Alain chatted with the captain, and both agreed to start work immediately so as not to lose any more time.
The surface of the ice shelf was 17 metres above sea level - just the right height for the deck cranes on the Mary Arctica to unload cargo straight onto the ice shelf. It looked like this job was going to be a piece of cake.
Unfortunately, it turned out not to be the case.
Not a swell time
The crew of the Mary Arctic drove steel pins into the ice to secure the ship to the ice shelf. But as soon as the first cable was tightened, the mooring pin was ripped out of the ice. A second pin snapped in two. The reason soon became obvious: a big swell from the east was coming into Breid Bay, kicked up by some offshore storm. The ship bobbed up and down three or four meters with every swell that arrived.
The captain had to make a bold decision: he would try to keep the ship steady and in place without mooring lines, using just the ship’s propeller and bow thrusters. It wasn’t an ideal situation, but something had to be done.
And so the work began. First, our waste containers and the deep freezer containing the precious ice-core samples our glaciologist friends took a few short weeks ago were loaded into the cargo hold of the ship. It proved a hellish job for the crane operator, who had to find a way to drop the four pins of his spreader crane right onto the four corners of the containers as the ship bobbed and tossed about continuously.
By 10 pm, we had landed 10 containers on the ice shelf. We happily went to sleep in an empty container, while the Mary Arctica sailed off a little ways to spend a quiet night out in the open water. Work would start work again at 7 am.
“By noon we should be finished,” said Alain.
But in the morning the swell had become worse. The captain made two valiant attempts to position his ship alongside the edge of the ice shelf, but it proved to be too dangerous. We had to wait until early afternoon, when the tide brought in a large bank of broken sea ice, sufficient enough to dampen the amplitude of the swell somewhat.
Finally!
It was close to midnight by the time we had 27 containers unloaded onto the ice. We also had several sledge-loads of building timber, and two shiny brand new vehicles: the much anticipated modified Toyota Hiluxes with tracks instead of tyres. They are the pride and joy of our chief mechanic, Kristof Soete, who fitted snow tracks on this these powerful 4x4s himself!
The Toyota Hiluxes are a very welcome transportation alternative to the slow, fuel-guzzling Prinoths and the skidoos, with which you can’t transport very much. The modified Hiluxes can carry five passengers and one ton of equipment, and can go up to 50 kilometres an hour. Life will be a lot easier for scientists going on field expeditions in the future.
All of us are looking forward to seeing how they perform on the ice!
The German scientists leave, and preparations are made to head to the coast to unload the supply ship, which is expected to arrive on Saturday, January 24th
Saying goodbye to our German friends
Yesterday the scientists from the Alfred Wegener Institute flew their last of their 20 scheduled flights scheduled for this season whiles based at the Princess Elisabeth station. They managed to conduct all scheduled flights, which is exceptional in Antarctica. Once the weather improves, they’ll fly to the Russian Novo station, where they’ll dismantle the magnetometers and the gravimeter before making one more flight from Novo to re-take radar data over an area that had not been correctly collected previously.
After this, some of the scientists will fly home to Germany, and the Polar 6 will be used for logistical flights between the German Kohnen and Neumayer III bases. If there is time left, they will do observation flights on the Filchner Ice Shelf in preparation of future survey. At the end of the season, the Polar 6 will be flown back to Canada for maintenance.
The AWI team was very happy with their stay at Princess Elisabeth station, and it’s been a season to remember. Not only did they manage to work out a few bugs in the instruments and collect excellent data, but the team also managed to generate a great deal of media interest when geophysicist Christian Müller spotted what he believed to be a possible meteorite impact site on the King Baudouin Ice Shelf.
However, glaciologists from around the world feel that this feature may actually be an ice doline. AWI team leader Graeme Eagles also consideres this to be a possibility now as well. But we’ll know more in a few months once the AWI scientists in Bremerhaven analyze the data the survey team collected this season.
In any case, Jan Lenaerts plans to visit circular feature on the ice shelf when he returns in November 2015 to continue his research for the second season of the BENEMELT project (thanks to funding from the 2014 InBev-Baillet Latour Antarctica Fellowship). The circular feature is within a day’s travel from the automatic weather station Jan set up this past season at the grounding line of the ice shelf. If possible, Jan hopes to take some ice radar data and extract some some firn cores.
A long journey ahead
For the past week, a team of eight (Alain Hubert, Kristof Soete, Walter Cumps, Ilir Berisha, David Rigotti, Nicolas Degand, Benoît Tyberhgien and Jos Van Hemelrijck) has been preparing to head to Breid Bay at the coast to unload the supply ship, the Mary Arctica, when it arrives. At the writing of this news, it looks as if the ship will arrive at Breid Bay by Saturday January 24th, which means Alain and the team will have to leave tongiht so they can arrive on time to meet the ship!
On the way out to the coast, the crew will take four Prinoth tractors, each hauling three or four sledges behind them. Over the next week, the different members of the team will have to make three trips back and forth in order to transport 30 containers of material to the station.
One thing that the tractors won’t have to haul back with them will the the new modified Toyota Hiluxes that the Mary Arctica is bringing. Able to drive up to 50 km/h on treads, the modified Hiluxes will be a welcome asset to the Princess Elisabeth team in Antarctica.
While the Prinoths will still be necessary to haul the very heavy loads, the Hiluxes will be able to haul up to a ton of materials and five persons, allowing greater flexibility in transporting crew, scientists and materials.
Countdown to the end of the season
At the station, work continues as the end of the 2014-15 season starts to approach. Canadian builder Jaques Touchette is preparing to jack up the central garage hall in order to add a couple of steel plates under the gliding foundations that were installed two seasons ago to compensate for the flow of the ice.
Meanwhile, Kristof has been taking inventory of everything at the station and making a list of what needs to be brought on the next shipment next year. Walter is preparing the unused skidoos to be put away for winter and bringing them to the winter park (the parking area of empty containers in the wind shadow of Utsteinen Ridge).
It’s hard to imagine that the end of the season is only five weeks away!
A bad storm made its way through Utsteinen over the weekend, creating a bit of inconvenience for the station crew, but also some recreational opportunities.
The wind began to howl
Bad weather had been predicted, and it hit us on Saturday night.
I awoke at 3:30 in the morning to a deep growling noise. The wooden wall next to my left ear was vibrating slightly from the wind rushing over and under the Princess Elisabeth station.
I opened the shutters of my window, which usually offers a brilliant view on Teltet Nunatak and the radio antenna to the east of the station. When I looked out, I could see nothing but white. It was a complete white-out.
Wanting to see if I might be able to get any kind of view outside, I decided to go to the office at the north side of the station. From its windows I could just make out the shape of the satellite dish trough the driving snow and the closest of several wind turbines spinning madly, its propeller blades folded backward to the wind.
From the tower window, which faces west, I could see great clouds of snow over the gap where the garage’s roof once was. The anemometer (which measures wind speed) at the airstrip measured wind speeds of 30 knots. The wind howled throughout the early morning hours, peaking at 40 knots around 6:00 am. But by the time we were having breakfast, it appeared that the worst of the storm was behind us.
With a storm comes inconvenience
Johnny Gaelens, our electrical engineer, nearly lost his way in the blizzard when making his daily visit to the southern ridge to collect data form the scientific instruments there. He reported that snow had infiltrated the shelter, and that one of the computers was down.
Showers and toilets had to be closed on Saturday morning to save water, as there was no way to fill up the snow melter. Someone has to shovel snow into it from the outside, and conditions were too adverse to be able to do that.
The weather was so bad that cook Riet Van de Velde and construction worker Ilir Berisha - who both have a habit of sleeping outside in tents - were forced to seek shelter inside the station. When the wind died down a bit Saturday afternoon and I was able to go outside, I found the tents crushed by the snow and the canvas shredded. Good thing they came indoors!
The day after
On Sunday, Jaques Touchette spent the better part of the day working with the snow blower to clear snow out of the parts of the garage we’re currently repairing, and getting things back to normal. Nicolas Degand and Chick Blaise donned their coveralls and took a pair of shovels to fill the snow melter. We had water once again!
However as Sunday is traditionally the day for recreation for the station crew - a day to enjoy the wonderful an unique natural environment of Antarctica - some of the outdoor sports enthusiasts at the station decided to take advantage of the freshly fallen snow for some winter sports activities.
The wind in the afternoon was just right for Riet to go kite skiing down at the airstrip, where he could zoom up and down the open expanses unhindered. Doc Jaques Richon, who is also a keen skiier, later joined Riet for a trip to Teltet Nunatak, which has excellent slopes to do some proper downhill skiing. "The fresh snow was absolutely wonderful!" Jacques told us.
Alain Hubert also took a break from his busy schedule and headed out on his own for a long cross country skiing session. When he came back to the station for supper, he was grinning all over “It’s good to have a break from all that paperwork!” he said.
While the storm created a bit of hassle, at least it provided some opportunities to enjoy Antarctica!
Since a team of scientists from the Alfred Wegener Institute (AWI) spotted a large circular ice structure during a geological survey flight above the King Baudouin Ice Shelf in Antarctica, glaciologists have been discussing the possibility that it could in fact be a giant ice doline, rather than an impact site for a meteorite.
Social media as a discussion forum
Jan Lenaerts, a glaciologist at Utrecht University who was also at the Princess Elisabeth Station this season studying the King Baudouin Ice Shelf, informed Graeme Eagles, leader of the AWI geological survey, that he and several glaciologists in the international scientific community (including Frank Pattyn at the Université Libre de Bruxelles, Doug MacAyeal from the University of Chicago, and Allen Pope from the NSIDC in Colorado) were discussing the circular structure in the King Baudouin Ice Shelf on social media.
The glaciologists were leaning towards an alternate explanation for the feature: an ice doline.
An ice doline is a kind of crater that is not as widely known or thought about as meteorite craters. They form when cavities in glaciers or ice sheets cave in, in much the same way as sinkholes can form over caves in limestone areas. In glaciers, the cavities form much more rapidly than limestone caves, by the drainage of meltwater from so-called englacial lakes or water pockets. Ice dolines have been known since the 1930s from observations of ice craters in Greenland and the Antarctic Peninsula, where the ice melts in summertime in larger quantities.
New hypothesis, new questions
Just like with the impact crater hypothesis, new questions are starting to come to mind as a result of the ice doline hypothesis. Ice dolines are a well known phenomenon on ice shelves in West Antarctica, which has been losing ice at an increasing pace. If ice dolines are more common than previously thought in East Antarctica - a region where ice mass balance has been relatively stable - it may force researchers to reconsider how stable East Antarctica is in terms of ice mass loss.
For the AWI survey team, the last few days have shown that modern scientific discussion is not confined to the ivory towers of learned meetings, technical papers, and lecture halls, but that public fora and social media play a tremendous role.
What's next?
The hard drives containing the terabytes of data that were collected by the Polar 6 team will travel back to Bremerhaven and be analyzed over the next few months. If the results enable either or both hypotheses to be ruled out, an article about the process will be prepared for peer review, publication, and further discussion amongst the scientific community. Usually, this process generates follow-up questions, which might require new field resarch.
For his part, Jan Lenaerts has already expressed interest in visiting the circular structure during the 2015-16 research season, as he continues research for the BENEMELT project he's currently working on, thanks to a research grant from the InBev-Baillet Latour Antarctica Fellowship. The BENEMELT project aims to investigate how much snow melts on ice shelves in East Antarctica, by how much melt will increase in the future, and how it could impact ice shelf stability and resulting sea level rise.
The Princess Elisabeth station team looks forward to supporting glaciological resarch next season!
A follow-up interview with AWI survey team leader and geophysicist Graeme Eagles is available on www.sciencepoles.org
The station crew keeps busy as they implement a solution to deal with the garages, which have been moving with the slowly flowing ice over several years.
Abuzz with activity
Everyday at noon, someone at the Princess Elisabeth station continues the daily weather balloon launches for Alexander and Quentin, now back in Belgium. The scientific instruments nestled in their different shelters collect data to be sent via satellite connection to computers eagerly awaiting information in Europe and around the world. Our guests from the Alfred Wegener Institute fly their daily observation flights over East Antarctica or the high plateau. And everyone patiently awaits the ship that will bring lots of goodies for the next season.
But all is not quiet at the Princess Elisabeth Station. There is a lot going on. The station’s staff is working very hard around the clock. The mechanics, the electricians, the plumbers, the carpenters and the jacks-of-all-trades keep this place running.
And at the moment, the crew is busy dismantling the garages.
Why would they want to do that, you might ask?
Firstly, there is not enough room to store everything. We need more space to protect vehicles and equipment over the winter months.
Secondly, the north and south garages of PEA are built on the ice. The ice just behind the ridge where the station is built does not move as fast as a glacier. But it does move - eight centimetres to the west and eight centimetres down every year. Over the years, the garages, which are built of wood, started to tilt and crack more and more.
A cunning plan
The PEA staff had to come up with a cunning engineering solution: new garages built not directly on the surface of the ice, but onto supporting beams that will be anchored to the rock on Utsteinen Ridge on one side and the rest on a sliding support on the ice. The support is a massive trestle made of steel-capped wooden pillars sunk into the ice and frozen solid.
To test the feasibility of the engineering solution, the station team conducted a trial last year in the central part of the station, where the tower leads into the garages. The solution seems to work fine.
After the supply ship arrives - which will hopefully be next week - the timber for the new garages will be unloaded from the Mary Arctica and transported to the station.
The new garage must be ready before the end of the season.
There’s still lots to be done, for sure!
The Princess Elisabeth team gets a surprise visit from a number of German VIPs, including two ministers, a member of the Bundestag, and AWI senior staff.
A German delegation arrives unexpectedly
With not one but two different planes arriving at Utsteinen airstrip, this past Saturday was a busy day! After AWI's Polar 6 landed in the afternoon after yet another observation flight, a second plane circled over the Princess Elisabeth station at low altitude and landed five minutes later.
This Basler was coming from the Russian station Novo. Amongst its passengers were three German politicians: two ministers and a member of the Bundestag, the German Parliament in Berlin.
Princess Elisabeth station manager Alain Hubert was at the airport to welcome all the VIP's: Dr Eva Quante-Brandt, Minster of Education and Science of the Free Hanseatic City of Bremen (where Bremerhaven is located), Cornelia Quennet-Thielen, German Federal State State Secretary and Department Head at the Federal Ministry of Education and Research, and René Röspel, a member of the Bundestag's Committee on the Environment, Nature Conservation and Nuclear Safety. They were accompanied by senior staff members of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Germany’s polar research institute headquartered in Bremerhaven.
Since the weather was not so good at Novo station, the delegation decided to take a detour and have a look at AWI’s Polar 6 aircraft, which is based at the Princess Elisabeth station for the 2014-15 research season. "We also wanted to take the opportunity to see the Belgian station,” remarked Minister Quante-Brandt.
We were all delighted at her remarks, and told her that as Belgians, we were proud to work at the Princess Elisabeth station! "You rightly should be!" answered the minister.
Showing off the station
After their inspection of the Polar 6 and its impressive load of scientific instruments, the delegation made their way to the Princess Elisabeth station for a short visit. Our cook, Riet Van de Velde, served them some biscuits and freshly baked "pains au chocolat".
Over a hot cup of coffee, the ministers marvelled at how cosy a polar research station can be on the inside, in stark contrast to such a cold and hostile environment outside.
We then showed our VIP-guests around in the technical heart of the station. With great interest they listened to Johnny Gaelens, our electricical engineer, who explained how the station’s renewable energy was produced and its use efficiently managed.
Their interest in the station’s functioning was certainly not feigned. Before heading back to the plane, René Röspel asked what it would take to equip his house in Germany with sufficient solar panels so he could live off the electrical grid.
As the plane was taking off, we felt very happy that the German officials had taken the time to visit us at the station. We certainly made an impression!
During their stay at the Princess Elisabeth station, researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Germany, have discovered a possible meteorite impact site during an aerial geological survey mission to study the geological history of Antarctica.
A new discovery
On December 20th, while on mission aboard AWI’s Polar 6 aircraft over the Princess Ragnhild Coast, geophysicist Christian Müller from Fielax (a company supporting the survey), looked out of the window of the aircraft and spotted an unusual formation in the ice over the King Baudoin Ice Shelf.
“About 5 or 6 kilometres away from the aircraft, I saw a massive circular structure about 2 kilometres across,” Dr Müller explained. “I wondered what could have created such a large feature in the ice.”
After returning to the Princess Elisabeth station, which AWI is using as a base of operations for the Polar 6’s survey flights this season, Dr Müller decided to have a look into the scientific literature. He wanted to know if there might be a record of some kind of impact event that happened in the vicinity of the King Baudoin Ice Shelf in recent years.
Digging deeper
After a bit of research, he found two separate studies to support the idea that the circular scar in the ice shelf could have been created by a falling meteor.
A study done by American and Canadian researchers using infrasound recordings (recordings of sound below the range of human hearing) from several sources, including Germany’s Neumayer Station III, concluded that a large body likely fell to Earth in the vicinity of the King Baudoin Ice Shelf in East Antarctica in 2004. In a separate study, scientists at Australia’s Davis station observed a dust trail high up in the atmosphere consistent with a trail left by a falling meteor. The Australians estimated that the falling object would have touched down in the area of the ice shelf.
“There are two lines of inquiry that support the hypothesis of an impact event,” affirmed Graeme Eagles, geophysicist and leader of AWI’s geophysical survey team based at the Princess Elisabeth station this season. “If the structure is indeed the result of the 2004 impact, we would expect it to have undergone about 10 years of alteration by processes such as snow accumulation, erosion by the wind, and deformation by the flow of the ice shelf itself.”
Six days after its initial discovery, AWI scientists conducted a more detailed aerial survey of the circular feature in the ice shelf, taking photos and videos, and collecting laser altimeter and radar data mapping the feature’s contours in detail.
Further investigation needed
While current evidence points to a possible meteorite impact site, the AWI team is cautious to say for certain whether the 2 kilometre-wide circular scar in the ice shelf was indeed caused by a large meteorite. AWI’s experts in Bremerhaven need to process the data the team in Antarctica has collected, and further investigation is needed.
And as the AWI team in Antarctica was sent there to conduct a geophysical survey of Antarctica’s bedrock to investigate the continent’s geological history, and not a meteorite impact site, they don’t have the means to conduct any thorough, in-situ investigation at the moment.
“If we could generate a plausible argument that this might have been the site of an impact, then we’d like to return to the site to do in-situ work,” Dr Eagles explained. “We’d certainly bring in more people to widen the range of expertise.”
More research at the site might include drilling into ice shelf to see if there is further evidence of a meteorite impact event. However it will have to wait. “We have to finish the survey we came out here to do,” Dr Eagles said. “This circular structure will have to go on the back burner until then.”
A full interview with AWI survey team leader and geophysicist Graeme Eagles is available on www.sciencepoles.org
Scientists and crew spend a unique New Year’s Eve in Antarctica, thanks to some improvisation form the station's cooks! New Year's can be fun in Antarctica!
No flights today
The weather was bad on New Year’s Eve. Low clouds obscured the mountain tops of the Sør Rondane mountain range to the south of us. It was an impressive yet eerie sight to see those mountains shrouded in clouds. Usually you can see very far in all directions.
Brad and Weston, the pilots of the Alfred Wegener Institute’s Polar 6 aircraft, decided to postpone their daily survey flight and wait to see if the weather would improve. However, two hours later visibility got even worse, and they had to cancel their flight for the day. While GPS could be used to help a pilot navigate in poor visibility, there are no landing radars or radio beacons in Antarctica like you have in Europe, so landing a plane safely would be an issue. Flying should be done only in good visibility conditions in this part of the world.
Fire up the barbecue!
That night, for New Year’s Eve, our cooks, David Rigotti and Riet Van de Velde, suprised us with a unique and impromptu dinner idea: a barbecue! They had a small, controlled fire in two steel half-barrels going in the parking area behind the station, and the bulldozer’s scoop was filled with snow to chill several bottles of cava and cans of beer. Despite the grey weather, we had a wonderful time!
Canadian co-pilot Weston Nicholson decided to attend the party wearing shorts. He insists on wearing shorts when he’s not flying. I suppose growing up in Canada has made him quite resistant to the cold. The cava left for too long in the glasses on the table outside was frozen solid!
When midnight finally came to Utsteinen (although you’d never know if you didn’t have a watch, given the 24-hour daylight this time of year), German scientists, Canadian airmen and PEA staff all wished one other a happy 2015.
In spite of the grey and frigid weather, we weren’t in a hurry to head back inside. How often does one get to ring in the new year in Antarctica?