Antarctica - what is it like now?
Antarctica is a continent located in the very south of the Earth. Its center is approximately
There are also entire “buildings” made from icebergs -with “windows”, “arches”, “columns” and caves. The color of ice “sculptures” and “architecture” is all shades of blue, from light blue to turquoise and even lilac. Even in cloudy weather you can see the flickering of an iceberg coming from somewhere inside. And in the sun the blue of the ice shines so much that you can’t even see it without sunglasses.
It's cold in Antarctica now. But not everywhere.The record low temperature was indeed recorded on the continent of Antarctica (about -90°C), but deep inside the eastern part of the continent. If you decide to discover Antarctica, you will most likely do it in the western part of the continent, on the Antarctic Peninsula. And here a surprise awaits you - a real Antarctic summer, with a noisy diversity of life and +15°C in the sun. The peak of “heat” occurs at the end of December - beginning of January.
What happened in the past?
And in the past, Antarctica was very different from the icy continent that exists now.
115 million years ago - Cretaceous era— Dinosaurs rule the world. The supercontinent Gondwana breaks up.
Hannes Grob (map) and Mario Reedy, CC BY 3.0, via Wikimedia Commons
INJurassic period, 180 million years ago, Antarctica waspart of Gondwana. This ancient supercontinent was breaking up and no longer exists. 180 million years Gondwana, consisting of Africa, Antarctica, Australia, India and New Zealand, begins to break up. Dinosaurs have ruled the world for almost 30 million years. Afterwards, the first flowering plants begin to appear, as well as mammals and birds. The South Atlantic is born with the breakup of Gondwana.
80 million years ago - the Cretaceous era.Antarctica is semi-tropical and forested, the outer edge extends to the South Pole, and there is no ice cap.
Hannes Grob (map) and Mario Reedy, CC BY 3.0, via Wikimedia Commons
With the coming Cretaceous era, about 100 million years ago, Antarctica was covered by vast forests. They mainly consist of huge ferns and coniferous trees. About 96 million years ago
Australia and New Zealand separatedfrom Antarctica, and she began her solo voyage. For about 70 million years, the continent has been dominated by a semitropical climate, and it continues to drift south. 65 million years ago, an asteroid crashed into the earth off the coast of Yucatan, Mexico. Scientists are sure this is what killed the dinosaurs. They are no longer the dominant species - mammals have taken their place.
65 million years ago - the Cretaceous era.Dinosaurs are dying out and mammals are starting to take their place. Antarctica continues to drift south and becomes colder.
Hannes Grob (map) and Mario Reedy, CC BY 3.0, via Wikimedia Commons
During paleocene, 60 million years ago, Antarctica becomesnoticeably colder. The mainland has a cool temperate climate, similar to modern Britain. The mass extinction at the end of the Cretaceous period leaves empty niches once occupied by now-dead dinosaurs, giant marine reptiles and other flora and fauna. Many new species emerge to fill these niches.
DuringEocene, about 40 million years old, the first largeice caps. Antarctica settles over the South Pole. It is believed that this is in part due to the fact that the climate of the planets Earth gets colder as the level of carbon dioxide in the atmosphere falls.
53 million years ago - the Eocene era.Antarctica begins to isolate, the Transantarctic Mountains rise.
Hannes Grob (map) and Mario Reedy, CC BY 3.0, via Wikimedia Commons
eraoligocene(38-26 million years ago) finally secured Antarctica’s title as the coldest, windiest and southernmost continent on Earth.
38 million years ago - the era of the Oligocene.Antarctica settles over the pole, an ice cap begins to form, and the first penguins appear. Hannes Grob (map) and Mario Ridi, CC BY 3.0, via Wikimedia Commons
A 25 million years ago, duringmiocene, the entire Antarctic continent is coveredice. 20 million years ago, the Antarctic Convergence is formed - a zone of the Southern Ocean surrounding Antarctica, in which cold, north-flowing waters meet the warmer waters of the Pacific and Atlantic oceans.
When Antarctica separated from other massifsland, the Antarctic Circumpolar Current emerged, which caused continental weather systems to become more isolated from the rest of the world, temperatures continued to fall, and the ice cap began to grow. Hannes Grob (map) and Mario Ridi, CC BY 3.0, via Wikimedia Commons
The new cover glaciation, which began in the Miocene, already in the latePliocene(7-0 million years ago) even surpassed itmodern sizes; As glaciation develops, West Antarctica, previously a group of isolated terrane islands, unites with East Antarctica into a single massif.
When Antarctica separated from other massifsland, the Antarctic Circumpolar Current emerged, which caused continental weather systems to become more isolated from the rest of the world, temperatures continued to drop and the ice cap began to rise. The Antarctic Circumpolar Current is a cold surface oceanic current with a length of up to 30 thousand km and a width of up to 2.5 thousand km in the Southern Hemisphere, enveloping between 40 ° and 50 ° S. sh. from west to east the globe. This is the only current on Earth that passes through all meridians.
It is the circumpolar current that isolates Antarctica's weather systems from the rest of the world.
What is hidden under the ice of Antarctica?
For a long time, scientists believed that Antarcticais a solid continent that was once one with Australia, and then covered with a kilometer-long layer of ice. But the latest evidence has given new ground for thought: the geology beneath the glaciers suggests that Antarctica is made up of many ancient continents.
A team of geophysicists from the University of Kiel inGermany has conducted a new study of the icy continent. It turned out that East Antarctica consists of several cratons, which are the cores of continents that existed earlier. A craton is an ancient platform, a stable section of continental crust from Archean times. Cratons occupy most of the volume of all continents, located in the central part of the plates and spreading over millions of square kilometers. These areas of the earth's crust are incapable of transformation by crushing rock layers and folding them.
Author: Adaykz from Russian Wikipedia — Ported from ru.wikipedia to Wikimedia Commons by Adaykz., Public domain
According to scientists, due to the fact that the continentso remote and buried under the ice, Antarctica is something of a blank spot on the geological map. The researchers used data from the gravity field of the European Space Agency (ESA) and the stationary satellite Ocean Circulation Explorer (GOCE) to fill in the gaps.
During a scientific project, scientists managed to removeice in a virtual model of Antarctica and focus on lithospheric plates. The crust of the eastern part of the continent is thicker than that of the western: its thickness ranges from 40 to 60 kilometers. The areas have a very clear thickness boundary, which indicates the presence of fragments of mountain ranges under the frozen soil. To better understand the shape of these formations, geophysicists need to drill wells and get samples from the rock.
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