Geography Reference
In-Depth Information
Sub-glacial lakes represent another extraordinary environment within the Antarctic that
might contain evidence of life. These lakes are located underneath large ice sheets. Over
150 have been identified by scientists and owe their origin to localized melting, pressure
points, and geothermal heating from the earth. While ongoing research does not expect to
uncover evidence of larger creatures, there may well be microbes within these sub-glacial
lakes that endure an environment in which there is no light, extraordinary pressures due
to the weight of the ice sheet, and temperatures that are always below zero. Sediments on
the bottom of the lake might provide a food resource for such microbes. Studying these en-
vironments is an immense challenge, especially as scientists are eager to avoid any cross-
contamination. When considering the water and aerial environments, the presence of birds,
seals, penguins, whales, fish, and smaller creatures such as krill is noteworthy. The South-
ern Ocean is immensely rich in micro-organisms such as algae and plankton and contains
the coldest and densest water in the world. Consequently, more oxygen is dissolved in the
sea and currents help to bring nutrients from the seabed to the surface. The surface-level
algae provide food for shrimp-like krill, which in turn provide nourishment for fish, seals,
whales, and birds. A marine food chain enables a reproductive cycle maintained by inter-
dependent species. The marine ecosystem in the waters surrounding the Antarctic is com-
paratively simple but at the same time varied, given the life forms also found on the bottom
of the ocean and sea floor such as sponges, star fish, and the like.
The bird life found in the Antarctic includes penguins and albatrosses. The penguin family
includes the Adélie, Chinstrap, King, Emperor, Gentoo, Macaroni, Rockhopper, and Royal
Penguin. Thanks to films such as The March of the Penguins and Happy Feet, many read-
ers will be familiar with the Emperor Penguin, which is the largest member of the penguin
