First-Time Visitor to Antarctica Paves Way for Geomagnetic Observatory
Having studied Earth’s magnetic field since the 1970s, Dr Jean Rasson from the Royal Meteorological Institute of Belgium (RMI) reflects on his first expedition to Antarctica, where he has been tasked with finding an ideal location to set up a geomagnetic observatory to be built at a later date. Dr Rasson will be on the last plane out as the station closes its doors for the 2013-14 season.
What have your research objectives been for the season?
At the department of geophysics of the Royal Meteorological Institute of Belgium, we deal with observing and measuring the Earth's geomagnetic field.
When I began working at the Institute in the late 1970s, I realized that to get a good understanding of the Earth's magnetic field, one has to observe it not only in Belgium, but elsewhere on the planet also. So in the 1980s and 1990s, we started working on installing and improving magnetic observatories in foreign countries, especially in places where there weren't that many projects to measure the geomagnetic field.
In 1993, we set up a digital observatory in Patagonia, southern Argentina. From that point on, we started cooperating with other countries such as Mexico, Colombia, Cuba, Russia, Indonesia, Pakistan, Mozambique, the Philippines, and others.
Together with colleagues from other countries, our ultimate goal is to create global coverage of the Earth's magnetic field using magnetic observatories. You need to look at the magnetic field from as many evenly spaced observatories around the world. And we're enthusiastic about the measurements we're taking. We consider this data collection as a contribution to scientific knowledge on a par with publishing scientific research papers.
And you also wanted to take some magnetic field measurements in Antarctica?
When we heard that the Princess Elisabeth Antarctica research station was going to be built, naturally we were interested in taking advantage of this opportunity to observe the geomagnetic field down there. Providing geomagnetic observations over Belgian territory is one of our core tasks.
What have been your specific objectives during the 2013-14 season?
In accordance with the requirements set out by the team of the Princess Elisabeth station, we prepared a non-magnetic shelter to house instruments to measure the Earth's magnetic field there.
This shelter isn't in any way standard. Given that there must be no magnetic interference, the shelter must be built from non-ferromagnetic materials (iron or steel is forbidden). It must be built far away from existing and planned magnetically perturbing buildings and equipment, as well as magnetic field generating electric devices. The shelter – even down to the locks and hinges – needs to be made of plastics, fibre glass, aluminium, bronze, brass or a special alloy like heat treated A4 stainless steel.
We've spent three years putting together, modifying and testing a hemispheric dome-shaped fibre-glass shelter. It was shipped by boat to Antarctica in a 20 foot container this season and trailed to the station by sledge convoy.
Our plan is to install the shelter on rock. On rock, its location stays fixed, unlike on the ice, where it can drift as the ice flows. However we’ll need to set up the device on a flat, wooden base anchored to the rock.
The shelter has a diameter of about four metres, and it will be high enough so that the instrument’s electronic consoles (which are slightly magnetic) can be put on shelves above and sufficiently away from the sensors, so as not to interfere with the measurements.
How many instruments will be inside? What measurements will you take?
Inside the shelter, we plan to set up four concrete pillars, which are fully independent from the wooden base. They'll be set up in such a way that they can measure Earth’s magnetic field continuously and with absolute accuracy. The magnetic field being a 3D vector, we need to measure three relevant quantities (e.g. intensity and two directions of the magnetic field) in order to fully quantify it.
Another instrument, a single triaxial variometer magnetometer, will measure changes in Earth’s geomagnetic field in 3D at a high sampling rate (up to 10 samples per second). This will give us a time series record of changes in the magnetic field.
We plan to use two other instruments (a proton magnetometer and a Diflux) to measure the magnetic field’s intensity and direction with absolute accuracy. This will help create accurate baseline measurements the triaxial variometer magnetometer will take.
At first, a person will need to be on hand to take certain measurements. The proton magnetometer can take measurements automatically, however the Diflux needs to be operated by a human observer a few times a week. This is a problem at the Princess Elisabeth station, since it is unmanned in winter. In order to solve this problem, we plan to deploy our new AUTODIF device. This is a robotized Diflux instrument, which can operate automatically and thus take measurements during wintertime, making a human operator unnecessary. We’ll have an opportunity to present the new AUTODIF device to our readers in due time.
We’ll use an Internet connection to get the data from the variometer in real time, and later on,once it’s been installed, we’ll be able to control, monitor and process the data from the AUTODIF.
Will you start collecting data this season?
No, this season the instruments won't be set up yet. This season my main task has been to select the best place to set up the shelter. I’ve been taking magnetic measurements at different locations that the station manager has proposed to make sure there is no magnetic interference in those locations.
We won't even take the shelter out of its container until next year, and the station team won’t start building the foundations of the shelter until then, either. During the second part of the 2014-15 season, we plan to have the shelter, the electricity, signal cables linking the shelter to the station, and the communications set up.
What is the long-term plan for the instruments in the shelter?
Our final aim is to get a permanently working and fully certified magnetic observatory at the Princess Elisabeth station in line with the standards of the INTERMAGNET consortium. Our wish is to have it operational for as long as possible. This will provide the scientific community with high-quality and long-term data from a region of Antarctica where there aren’t any observations of Earth’s magnetic field yet (the closest INTERMAGNET observatory is at Mawson station, 1,600 km away). We'd also like to use the observatory at the Princess Elisabeth as a case study and an extreme weather test site for the automatic systems we’re developing in addition to the AUTODIF.
Besides finding a good spot to put the shelter, did you do anything else this season?
I took magnetic field measurements at Belgium's old Roi Baudouin station at the coast 200 km away from the station. The idea is to connect these measurements with the ones I plant to eventually make at the the Princess Elisabeth station. There were four years' worth of continuous magnetic field measurements at the Roi Baudouin station when it was in operation in the 1950s and 60s. So we hope by taking simultaneous measurements today at both the Roi Baudouin and Princess Elisabeth stations to see how the magnetic field differs over the 200 km between the two stations. Knowing this will help us to make use of the magnetic field data taken at the Roi Baudouin station in the 1960s and continue this time series at the Princess Elisabeth station.
This is your first time in Antarctica. What are your impressions of the surroundings and daily life on the continent?
This experience has certainly been something completely new for me. I had been to Siberia and to trips in the Rocky Mountains, the Alps and the Andes. However the sheer size of this continent, its isolation, geography and its extreme weather came as a surprise to me even though I had read up and prepared.
Upon arrival at the Princess Elisabeth station, I was impressed by the beauty of the surroundings. The combination of high and steep mountains, snow, ice and local rock formations is an awesome sight to behold. The long trip from Cape Town, South Africa to the station using a combination of special aeroplanes made me realize the enormous efforts that went into successfully setting up this Belgian Antarctic base.
After we had alighted from the plane and were approaching the station on a skidoo, the building came clearly into view, and I was struck by the surreal elegance of its stainless steel structure set upon the rock ridge near Utsteinen. I could see the extensive logistical facilities including garages, workshops, tractors, bulldozers, cranes, etc… The long, easily accessible ridge that was covered with wind turbines, transmitting antennas and scientific shelters is a testament that the site has been carefully selected for its purpose: research on-site, but also easy access to the Antarctic Plateau and to the coastal areas.
As I entered the base, I was given a full tour by the station manager, Alain Hubert, who explained to me that this was a “zero-emission” building. At first, I couldn’t believe that there was no air heating system on inside the base while the outside temperature was -12°C. Yet it felt comfortable enough to wear only a T-shirt inside. The building is insulated by 50 cm walls containing polystyrene insulation, and the windows are made of several layers of glass sandwiched around an insulating vacuum layer. The warmth inside comes from a combination of a greenhouse effect created by these windows, sound insulation, and the heat generated by equipment and peoples’ body heat.
I was also able to have a look at the electricity generating system, which uses photovoltaic panels and wind turbines to provide the base with electrical power while charging a huge bank of batteries that power the station when wind and solar energy production is low. There is also a snow melter to supply drinking water as well as a water purifying system to treat used water. As I took my my first shower at the Princess Elisabeth station, I could appreciate the perfect functioning of the station’s water heating system, which is heated with solar thermal power.
The staff and fellow scientists at the base were very helpful and welcoming. I felt immediately at home and efficiently supported while doing my measurements. We had many excellent lunches and dinners together.
You're also one of the last scientists to be at the station during the 2013-14 season.
Yes, I'll be on the last plane out. We'll be closing the station for the Antarctic winter when we leave.
Picture: Jean Rasson taking measurements of Earth's geomagnetic field on the site of the former Roi Baudouin station at the coast. - © Jean Rasson