Antarctica, the planet's natural research laboratory
South Africa's scientific involvement at the South Pole is invaluable, writes Ian Meikeljohn.
Antarctica is the coldest, highest, driest, windiest and most remote place on earth. In terms of size, if the islands surrounding the continent are included, it is larger than the United States and about double the size of Australia. Why then is there such intrigue surrounding the Antarctic?
Much of the fascination stems from the heroic acts of people who notched up “firsts” there; some of the better-known explorers are Roald Amundsen, Ernest Shackleton, Robert Scott and more recently Ranulph Fiennes.
It is the most inhospitable place on the planet and it is possibly the romantic notion of conquering nature or even simply surviving in this beautiful icy wasteland that draws people to the vast continent.
There are other reasons Antarctica is important, mostly because of its role in driving natural systems on the planet. Accordingly, it has been recognised as a continent for science and is identified as such by the 46 signatories of the Antarctic Treaty.
The member nations which, some argue, are interested only in the area’s vast mineral wealth, do nevertheless hold all their land claims there in abeyance. South Africa was the second nation to sign the treaty and, given its location as a gateway to the Antarctic, is an important player in Antarctic science and politics.
So why would South Africans be interested in conducting science in the Antarctic?
Many of the weather systems that affect us in South Africa, particularly in winter, originate in the cold Antarctic waters.
These provide the food that sustains large populations of whales, seals and birds that inhabit the environment and that are crucial to the functioning of planetary ecosystems.
The earth’s magnetic field is concentrated over the polar regions and the Antarctic is, therefore, an ideal laboratory for studying the upper atmosphere.
For the earth scientist, Antarctica was once part of Gondwanaland, joined to Southern Africa, and provides a window into plate tectonics and continental drift and unlocks some of the geological history of our country.
The few areas of open land are places where only the most primitive organisms survive and are sensitive to the smallest environmental changes, thereby allowing excellent opportunities to study evolutionary change.
The sensitivity of the environment to change offers the best reason for conducting science there. In this age, when the human impact on earth is in the media daily, changes in Antarctica provide a planetary early-warning system, particularly for climate change.
The ice continent holds more than 60% of the earth’s fresh water and if it all melted estimates suggest that global sea levels could rise by as much as 75m. Recent melting of the Larsen B ice shelf, where 800km² of ice disintegrated in just over two months in 2002, prompted a media frenzy about the potentially disastrous effects of global warming. The somewhat smaller Wilkins ice shelf began collapsing off Alexander Island earlier this year and is expected to disintegrate in the next austral summer.
The two events need to be contextualised; they occurred in the Antarctic Peninsula in areas marked by intense localised warming, where temperature increases substantially exceed global trends.
In apparent contrast satellite imagery shows that the surface of some parts of Antarctica’s interior are cooling, but models suggest that observed drops in temperature are a consequence of complex feedbacks from global warming. In reality the melting of the ice shelves are alarming events that should wake decision-makers out of their slumber to the consequences of climate change.
It is clear that more research is needed to elucidate the causes and consequences of human impact on earth and clear evidence of the need for Antarctic research.
In polar regions ground that is permanently frozen is called permafrost and this underlies about 25% of the ice-free terrestrial environment of our planet.
Summer warming leads to the seasonal thaw of the surface zone of permafrost, known as the active layer. Because permafrost is a thermal condition of the ground, its distribution and behaviour are sensitive to short and long-term climate change.
As the current climate warms, the increased thaw of the uppermost permafrost and thickening of the active layer results in ground subsidence, accelerated erosion and related hydrological and geochemical changes, as now observed in northern polar regions.
The dynamics of permafrost and its active layer are important components of the terrestrial cryosphere, with direct and indirect couplings to the global climate system. The effects of permafrost dynamics on the biology are important considerations when determining the impact of climate change.
Investigating permafrost and its feedbacks in the global climate and biological system are a priority.
A National Research Foundation (NRF) funded project involving academics and students from the universities of Pretoria (UP), Fort Hare and Uppsala (Sweden), under the leadership of the UP, has established research in the Antarctic and sub-Antarctic to develop a regional understanding of changes in permafrost temperature, active layer processes and climate interactions.
Study sites are in western Dronning Maud Land, Antarctica, where the South African base, SANAE IV, is located, and in the interior of Marion Island (sub-Antarctic). The project forms part of a larger international global thermal state of permafrost core project for the international polar year in 2007 and 2008. At each site ground temperature (to a depth of 2m), ground moisture and soil movement rates are measured.
Earliest data indicate that the active layer depth in western Dronning Maud Land is 20cm at the coast and less than 10cm at an altitude of 1 000m.
Obviously, with time, it will be possible to determine the effect of climate change through long-term monitoring of the permafrost.
South African Antarctic research is funded by the NRF through the South African National Antarctic Programme (Sanap), where project approval follows an evaluation process using peer-review.
The provision of scientific bases and logistical support is supplied by the Sanap, through the directorate, Antarctica and islands of the department of environmental affairs and tourism.
Three bases are maintained by Sanap, namely SANAE in western Dronning Maud Land, Antarctica, and Marion and Gough Islands in the sub-Antarctic. SANAE is in an area originally claimed by Norway, a claim held in abeyance as part of the Antarctic Treaty.
Marion Island represents South African territory that was annexed in 1947, while Gough Island is a British island, where Sanap runs a scientific base.
Ian Meikeljohn is an associate professor in geography, geoinformatics and meterology at the University of Pretoria