Is Zealandia Earth's 8th Continent?

How many

continent

s does the Earth have? Some might think this is an easy question, but it may not be as simple as you think. If you ask an American like me, you'll probably get the answer seven: North America, South America, Europe, Africa, Asia, and Australia. Oh yeah, and Antarctica, but ask a person from South America and they'll tell you six Americas, which is just one

continent

, Europe, Africa, Asia, Australia, oh yeah, and Antarctica, so someone who knows a lot about geography I could tell you that nothing really divides Europe and Asia, so there are only five continents America is not mine but Eurasia Africa Australia oh yes and Antarctica and technically before the Suez Canal it was Doug Africa and Eurasia were also connected by land so some people like to say that there are only four continents America Afro-Eurasia Australia oh yes, and Antarctica, but there are those who would argue that all of these have still left out one continent, the eighth continent, the continent of Zealand, within of the Pacific Ocean, lies a piece of continental crust that has risen more than a kilometer above the surrounding ocean surface.

Earth's crust and is geologically distinct from any and all surrounding bodies completely separated from Australia by the Quito Basin. It is almost five million square kilometers in area, which means it is almost twice the size of Greenland and almost two-thirds the size of its neighbor Australia, and although that may seem like it is covered in water, it is, but it is not. It is made of oceanic crust, but of continental crust; the same thing that you and I are sitting on right now, the only problem is that today of those 5 million square kilometers of continental surface 94% of the Earth's crust is below sea level and only the highest mountains of the continent remain above the ocean, which form the islands of New Zealand and New Caledonia.

In total, there are currently only about 350,000 square kilometers of Zealand above sea level, that is, less area than the US state of Montana, but this was not always the case for millions of years. The Earth's land surface was divided between two main land masses: Gondwana and Laurasia. The fragments of the large Pangea Zealandia were part of Gondwana and constituted about 5% of the super in total. The land area then Gondwana began to split up to become present day South America, Africa, India and Australia, oh yes, and Antarctica Zealand also split up, but as these continents separated, some of them, like South America South and Africa, were pushed against themselves, so they became. narrower but also higher than the opposite happened with the other land masses, so Antarctica and Zealand were stretched more, making them thinner, like stretching a rubber band because it became thinner than the rest of the continents as they The Landy floated slower in the Earth's molten mantle. just below modern sea level, but this means that there was a time about 180 million years ago, just as Gondwana was beginning to break apart, when Zealandia was in its full form and at the proper height above the oceans, 55 million Years after it separated from Australia, however, Zealandia had become almost completely submerged because of this, many people dismissed Zealandia as a true continent despite it being a huge piece of continental crust, so let's take a look. to what the criteria are to be considered a continent and see if Zealandia qualifies while it might seem easier to look at Earth's tectonic plates to decide our continents and oceans.

A second look reveals that this is not very useful at all. Some plates contain large portions of both land and ocean, such as the South American plate, which is more than 50% submerged and there are also a number of smaller plates that none of us would consider complete continents, such as the Caribbean Nazca or Juan plate. de Fuca, so we must look elsewhere to find what a continent really is. The idea of ​​Zealandia was first introduced in 1995 by Bruce Lyon Dyck and was expanded upon by Nick Mortimer and his team of researchers in a paper titled Earth's Hidden Continent of Zealandia, which was going to be the name of this video until So I decided to try to be a little more original than that, but in this The first thing given in the document is that the basic outline of what constitutes a continent is that a continent must have an elevation above that of the ocean floor which surrounds it.

A quick look at any ocean floor elevation map will show the shape of Zealandia rising more than a kilometer above the surrounding ocean. So at that point Zealandia gets an e-zpass second, it's more of a geological rule that says the continent's crust must contain a wide range of igneous sedimentary rocks and male morphic rocks, this is to maintain the islands and oceanic plates out of reach of things like volcanic islands. They are basically all igneous rocks and oceanic crusts are usually mostly basalt, another igneous rock, so both are disqualified. Rock samples from the sunken continent revealed a lot of variation in rock types, so Zealandia gets another pass.

Third, the continent must be thicker and less dense than the oceanic one. crust and therefore have a lower seismic velocity as we have seen, although the crust that makes up Zealandia is thinner than that of other continents, it is still noticeably thicker than the surrounding poche annika crust due to its geological composition of which we just talked about, it is also less dense than oceanic crust. So again, the fourth and final criterion is that the continent must have a well-defined extent that is large enough to qualify as a continent rather than a microcontinent or continental fragment.

An example of a microcontinent would be the island of Madagascar off the coast. The coast of Africa is still very big, but not big enough and this is where I get into a bit of trouble because, well, what exactly qualifies as continent size, let's take a look. Australia is the smallest official continent in quotes at seven million six hundred and ninety. two thousand square kilometers, so each and every largest land mass would definitely be a continent, then the largest island would be Greenland at two million one hundred and sixty-six thousand square kilometers, anything smaller would definitely not be a continent but another island, but Zealandia falls somewhere. in the middle, larger than the largest island but smaller than the smallest continent, this raises an interesting question: does a land mass only have to be larger than Greenland to be a continent or larger than or equal to Australia to be a continent of more than two million squares? kilometers or more than eight, we have never needed a more exact definition because today there are no landmasses between these two sizes, although in prehistoric times the

earth

was full of them like India and Arabia.

Nick Mortimer's article offers 1 million square kilometers as a possible limit. which would also qualify Greenland as its own continent so I don't like it, also this number is quite arbitrary with essentially zero geological basis, why 1 million 1,000,001 why not 999 thousand and so on, even more people dismiss this claim, however, based solely on the fact that Wald, yes, the entire shelf is almost five million square kilometers, most definitions of a continent include something like a massive expanse of land of which the land iya has very little, but proponents of Zealandia argue that if we studied the Earth and its continents as we do other planets, ignoring Zealandia's surface liquid state as a genuine continent would become apparent because it is still much higher than the surrounding oceanic crust.

I think the general problem is that we don't really have a good definition of what constitutes a continent and this is because, well, they are invented, we invented the idea a long time ago, when the

earth

was just land and sea with nothing in the middle, but now we have the sea, the land, Zealand, the Zealandia boom understood it and that is why no one today can agree on what exactly a continent is or even how many of them we have. So what do you think Zealand should be considered the eighth continent on Earth and exactly how many continents do you think there are?

Let me know in the comments and if you liked this video. I want to see more hey, how about you like and subscribe to this channel? I'll be back next week with another video, thanks.