A short lesson of antarctic toponymy

In the past, the strong South American current allowed the development of a warm and humid climate in western Antarctica, but this situation is finally coming to an end. Global sea circulation is shifting and northern Antarctica is now experiencing warmer yet drier conditions compared to the past, likely caused by the southward shift of the tropical zone: in fact, in tropical regions, rainfall often drops sharply and a similar process is slowly taking shape in Antarctica, which is creating sub-humid to arid environments known as warm dry heatlands. Depending on the area, these environments can be monsoonal or semi-arid, supporting dry sparse woodlands, open savannas, and in some rare cases even semideserts.
If global warming continues, the balance of these ecosystems will change, with deserts gradually replacing the other sub-humid habitats.

Within the warm dry heatland, two major ecosystems stand out. The largest and most famous is the Great Depresseaon, an expansive region that supports an incredibly rich community of organisms, all adapted to open landscapes maintained both by herbivore trampling and the arid conditions. In some areas of the Depresseaon, annual rainfall reaches as little as 400 millimeters. This scarcity is caused by the vast mountain ranges that act as barriers, halving precipitation compared to the coastal zones of the Antarctic Peninsula. However, the same mountains hold enormous groundwater reserves, feeding rivers that flow across the dry plains and create long green corridors of life. The resulting mosaic of habitats makes the Great Depresseaon far more biodiverse than other warm dry heatlands, which, despite receiving more rainfall, tend to be more homogeneous.
Alongside this ancient ecosystem, another geographic region is beginning to emerge: the Circo Atolls. This immense volcanic archipelago, comparable in size to Hawaii, was formed by a still-active hotspot shifting under the tectonic plates. Some older volcanoes are now sinking beneath the sea due to erosion, forming vast atolls that host unique species. Because of its recent formation, the archipelago is not yet as biodiverse as older island systems, but over time it will undoubtedly become a showcase of evolutionary innovation. The Circo Atolls partially connect with the Sparso Archipelago, which is being reshaped by rising seas. Many insular habitats there are vanishing, yet fragmentation has created new ecological niches, driving a decline in medium and large vertebrates but a increase in biodiversity among invertebrates and microvertebrates.

While northern Antarctica grows increasingly dry, eastern and western Antarctica are undergoing the opposite transformation. New sea currents are creating a humid climate, with rainfall that can locally reach 2500 millimeters per year or even higher.
This biome is known as warm wet heatland. Its most remarkable ecosystem is the Pantarctanal, one of the largest wetlands ever known. Depending on seasonality, as much as 70 percent of this area may be partially submerged, creating a dynamic and extremely productive environment. Alongside the Great Depresseaon, the Pantarctanal is now one of the key biodiversity hotspots of Antarctica.
Another important wetland lies further south: the Incenso Salt Lake. This vast basin was once buried under ice during the late Biancocene but re-emerged after the retreat of glaciers. Though colder than the Pantarctanal, its persistence over eight million years and its mix of fresh and brackish waters have allowed it to develop extraordinary biodiversity, especially among fish, insects, and plants.

Finally, Boitomb Island has undergone a dramatic transformation. Ice caps have disappeared from its lowlands, surviving only on mountain ranges. Some valleys can still accumulate up to two meters of snow, yet conditions are mild enough to sustain vast and dense forests. The channel separating Boitomb from the Neopolarica landmass has produced again an isolated ecosystem where cold-adapted flora and fauna evolved into highly endemic forms. With a surface area of around 200,000 square kilometers, Boitomb is much larger than it once was and contains a remarkable diversity of environments despite its harsh climate. Its southern latitude subjects it to the longest polar nights on Earth, with five to six months of continuous darkness each year, a challenge that has shaped the evolution of its unique life.