Dr Anjani Ganase discusses the most extreme environment on earth, the unknown continent, which has been positioned by the international community as a place of conservation, collaboration, and human accord.

Extreme environment

When learning about the seventh continent, Antarctica, it’s hard to really understand how alien this landscape is. On Google maps, there’s nothing but a blank white visual. This is the coldest, driest, and highest place on earth. Antarctica is covered in ice – in some locations five kilometres deep. It is a place that continues to defy human civilisation, ancient and modern.

Antarctica has some of the lowest temperatures ever recorded – -89.2 C the lowest ever recorded on earth at Vostok Station. Geographically, Antarctica is two parts, East and West Antarctica divided along the Transantarctic mountains with eastern and western faces controlling the flow of ice sheets, either east or west. Mount Kirkpatrick is the highest mountain on the continent towering 4,528 m (Mt Everest is 8,848 m) in the Queen Alexandra Range. East Antarctica is much larger than West Antarctica, with thicker ice sheets and higher elevations. The Antarctica Peninsula extends north from west Antarctica towards South America. Antarctica is surrounded by the Southern Ocean that whips around the continent. During the winter, sea ice forms and adds 19 million square-kilometres (records from 1981 – 2020) more than doubling the area (13.66 million squared-kilometres). During the summer the sea ice recedes to about three million km2. Within the Antarctic circle, you can experience 24 hours of daylight for several months in the summer, but there’s the same total (24 hours) darkness in the winter.

[caption id="attachment_1013105" align="alignnone" width="683"] Antarctica. -[/caption]

Antarctic wildlife

Life in the cold is mastered by only a handful of creatures. With no terrestrial wildlife, Antarctica is home to marine mammals that divide their time between foraging the relatively warmer oceans and coastal areas of the icy continent. Eighteen species of penguins are the only birds. The Antarctic food web is founded in the ocean. Phytoplankton are fed upon by krill (zooplankton) which are consumed by fish. The fish and the krill are the main source of food for most of the marine animals, penguins, seals, whales, and elephant seals. Leopard seals also hunt seals and penguins. The top carnivore is the killer whale that preys on all the marine mammals. Research on the wildlife is focused on estimating populations, and studying the adaptations to the environment, such as the diving physiology of penguins. Innovative ways have been devised to track Emperor penguins for example: satellite imagery of their colonies shows up as reddish-brown poo stains on the sea ice. From the stained areas, colony size may be estimated.

Research on what is hidden beneath the ice sheets reveals the long history and ecology of Antarctica. About a third of Antarctica’s continental shelf seabed sits below a layer of ice. For a study in 2021