In February 2017, all the media did nothing but write and talk about the discovery of a new continent - Zealand. Allegedly, it lies under New Zealand and New Caledonia for 23 million years, and all this time it pretends to be islands …
GEOGRAPHY LESSON
True, the newsmen were confused in the testimony and lost count, calling Zealand either the seventh or the eighth continent. Therefore, before moving on, it is worth refreshing your theoretical knowledge in the field of geography.
So what is a continent? Let's not philosophize slyly, but let's look directly at Wikipedia, which will give an accurate and understandable, at first glance, answer:
"The continent is a large massif of the earth's crust, most of which is not covered by the ocean, and the margins are below sea level."
It turns out that this is just a very large land mass protruding above the water, right? Yes and no. The most important thing for a continent, without which it has no right to be called such, is the presence of a continental crust. In terms of its thickness, it is many times greater than that of the ocean, and in addition, it is strikingly different from it in terms of geological properties. It is also extremely important to understand one thing: the continent and the mainland are by no means synonyms. Maximum - concepts close in meaning. (And this is the reason why our material will sin with endless repetitions.)
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WHO COUNTS HOW?
Now let me ask you: how many continents are there on Earth? Do not rush to smile: this seemingly simple question can put many in a puddle. The domestic school geography course assumes that there are six of them: Eurasia, Africa, South America, North America, Antarctica, Australia. But in the camp of geologists and geographers, not everything is so simple. For example, North and South America are connected by the Isthmus of Panama. And if so, then these are not two continents, but one: America, which includes two continents - the South and the North.
It's the same story with Eurasia and Africa: this pair is united together through the Isthmus of Suez. And now we get one whole: Afro-Eurasia.
Understandably, with this approach, the ranks of the continents are sharply thinning - and now there are only four of them.
Further more.
There is no unity in the international ranks of geographers: therefore, there are several traditions in the world of dividing lands into continents and parts of the world. The six-continent model is most widely used in Russia, in Spanish-speaking countries, and in Eastern Europe. In China, India and some countries of western Europe, Eurasia is divided in half - into Europe and Asia - and get seven continents.
Well, in Greece, on the contrary, they unite two Americas into one and get five continents.
In a word, the newly-minted Zealand can be simultaneously the eighth, and seventh, and even the sixth continent. All of these definitions will turn out to be correct, depending on the "continental model" chosen. Still, the key word in this definition is the word "new". Well, since we live in Russia, we will follow the precepts of Russian geographers, even if they drink globes on drink sometimes, and consider Zealand the seventh continent.
WHO DISCOVERED?
Strictly speaking, geologists from the Royal Research Institute of New Zealand did not learn about the fact that under New Zealand and New Caledonia lies a submerged continent, to put it mildly, not yesterday, and even less so in February 2017. But who would listen to them? Things turned out quite differently when they teamed up with leading geologists from institutes in America and Australia. At the head of 11 scientists was the American Nick Mortimer. By the way, commenting on the discovery of the seventh continent, he acknowledged the primacy of his New Zealand colleagues: "New Zealand geologists must be wondering why such a fuss has arisen." And he added that “this is not a sudden discovery, but a gradual realization. 10 years ago, we would not have had the accumulated data or confidence in interpretation to talk about the discovery of the continent.” In total, scientists have devoted about 20 years to this study. And this fact alone inspires respect and arouses confidence in their research.
SMALL BUT CONTINENT
Humanity's ideas about how the face of the Earth has changed are far from perfect. Alas, we still have not invented a time machine, and therefore we can not be sure whether all these supercontinent such as Kenorland, Nuna and Rodinia really existed. We are almost sure of the reality of Lavrussia. Actually, the very continental history of the Earth, mankind leads from Gondwana - a supercontinent that arose about 750-530 million years ago. This hulk swam in the midst of the world's oceans and burst at the seams: it is customary for any new house to shrink. True, in the case of Gondwana, the process dragged on for a long time: fragments of land ceased to be separated from it 53 million years ago. More recently - by geological standards.
Zealand was among these fragments. And for a while, she drifted in the ocean along with other continents. But then, due to the small thickness of the notorious continental crust, it sank under the waters of the Pacific Ocean and "spread" along its bottom - as much as 5 million square kilometers. Scientists managed to find out the true dimensions of Zealand relatively recently. They resorted to the help of a satellite and, thanks to new data, were able to refine a bathymetric map showing the bottom relief. And for the time being, the unspecified size of Zealand prevented its recognition as a continent: after all, according to certain geological indicators, the area of the continent cannot be less than 3 million square meters. km. And here - about happiness - the situation finally cleared up: it turned out that a block the size of the European part of Russia or India rests at the bottom of the ocean. What is it if not a continent, even the smallest one?
REWRIT YOUR TEXTBOOKS?
True, 94% of this beautiful continental surface is hidden under water. And on land, in fact, only the mountain ranges of Zealand flaunt in the face of New Caledonia, New Zealand and even a few islands. Scientists established their commonality with Zealand by the identity of the same continental crust: the samples taken from the bottom did not differ in any way from their "land" counterparts. Conversely, they were in stark contrast to samples taken in Australia. But for a long time it was believed that New Zealand is part of the Australian Plate - a large fragment of Gondwana, Earth's southern supercontinent, which broke away from India and Antarctica about a hundred million years ago.
But Mortimer and 10 of his colleagues proved that this is not the case. Australia is on its own, Zealand is on its own. So if you please rewrite the textbooks.
After all, Pluto has long been considered the ninth planet in the solar system. And then at one point they took it and downgraded it to the status of a dwarf planet. Nothing, astronomers survived this collapse of the usual coordinate system. And geographers will do it with geologists.
So, as soon as the discovery of scientists passes an independent examination, that is, other scientists agree to recognize Zealand as the seventh continent, the work of the publishers of school manuals will increase.
And New Zealand, together with other "mountain peaks" of Zealand, will have at its disposal any minerals found on the continent's underwater territory.
Vlad ROGOV