A short lesson of antarctic toponymy

The glacial period has a profound impact on Antarctica, particularly due to glacier expansion, which results in the emergence of new land and the retreat of shallow seas. During this period, the sea level can drop by as much as 250 meters compared to an interglacial period, leading to an increase in terrestrial habitats for organisms. It is estimated that Antarctica gains approximately 20% more dry land during these conditions, excluding the sea ice.

A significant factor contributing to this increase in land is the drainage of the inland sea of Antarctica, which corresponds to the present-day Weddell Sea. This drainage occurs when the volcanic arc of Antarctica, known as the Fire Bridge, completely closes, creating several endorheic basins with a lack of water supply and allowing the connection of Centro Island to mainland Neopolarica. Lots of this newly exposed territory lies below sea level, some areas even reaching depths of up to one kilometer. This region is referred to as the Great Depresseaon. The proximity to the Earth's mantle creates a unique microclimate in this Antarctic bioregion, resulting in temperatures up to 10 degrees Celsius higher than the surrounding areas because of Earth internal heat and local hotspots. This milder climate allows for the absence of snow cover throughout the entire year, fostering the growth of a lush ecosystem. Here, numerous shrubs and trees can grow faster because of the prolonged warm season, forming the only known forest in the trample steppe. This relatively large yet fragmented paradise becomes an important wintering area for many animals and is also home to several species that would typically be limited to the warmest areas of the coldvanna.

However, the drop in sea level does not only favor the creation of these rich and biodiverse dry land, but it also create almost inhospitable regions, such as those found at the edge of the ice pack. Not far from the Incense Salt Lake, a group of islands emerges, possessing a polar climate with very few plant species capable of surviving the short and cold summers. These islands are known as the Drop Islands and, even if seasonally connected with mainland thanks to sea ice, they do not support large animal populations due to their small size and barren environment. Nevertheless, these islands play a crucial role as stepping stones for many animals adapting to ice cap conditions. The presence of this relatively large intermediate bioregion between the productive trample steppe and the harsh sea ice is helping to forge hardy species like never before. This evolutionary process will be essential in the future of Antarctica, especially in light of the current global cooling trend.