A million years to recover: what happened to the Earth immediately after the death of the dinosaurs

18 ноября 2020, 13:37
The new issue of the YouTube channel Ridddle tells about the details of how the catastrophe that resulted in the death of the dinosaurs, and how the restoration of life on Earth then took place.

About 66 million years ago, at the end of the Cretaceous period, the planet lost its dinosaurs.

Everyone knows: this happened because of a global catastrophe. But what happened immediately after the mass extinction?

Everything was completely different than we used to think.

At the end of the Mesozoic era, a huge asteroid or comet crashed into the Earth, scientists are still arguing about this. The diameter of the celestial body ranged from 11 to 80 km.

That is, on average, it could be the size of the city of Washington.

When one edge of the asteroid hit the Earth, the other end was still higher than the Boeing 747's flight zone. Such a collision could not pass without a trace.

The asteroid left behind a giant crater that half-blocked the Gulf of Mexico. And no wonder: the crater has a diameter of 150 km and a depth of about 20 km.

This was not the first collision of our planet with a celestial body, but it became one of the largest.

The world changed in an instant. The impact caused a tsunami with a height of more than 100 m, which reached the territory of modern Texas and Florida. Other sources indicate a height of 300 m, for example, the height of the Eiffel Tower. And some argue that the first wave rose up to one and a half kilometers - five Eiffel Towers!

The asteroid pushed so much water out of the ocean that huge waves covered the coast for 10 hours.

And this was not the worst scenario. If the impact fell on a deeper place, the tsunami would be even higher.

The explosion that occurred when this celestial body fell was about 100 million times more powerful than the famous thermonuclear Tsar Bomb.

Forests within a thousand kilometers were destroyed in just a second.

Some scientists believe that the explosion was equivalent to 100 trillion tons of TNT.

It was enough to destroy the coastline, cause 12-point earthquakes and landslides all the way to Argentina, and they, in turn, caused new tsunamis.

A real chain of horror. It was impossible to survive, being in her path.

But that was only the beginning of the disaster.

The energy with which the asteroid crashed into the Earth was enough to set fire to the landscape within a radius of one and a half thousand kilometers.

Even huge dinosaurs like diplodocus died. Those who were not hit by the explosion or fire were dragged along by the retreating wave.

Tiny particles of rock and other debris were thrown high into the atmosphere, later geologists will find these fragments all over the world, because, after climbing up, after about 40 minutes, the particles began to fall rapidly.

They looked like drops of hot glass. Their kinetic energy was the equivalent of 20 million megatons of TNT, and all of it was converted to heat.

Each falling particle turned into an incandescent lamp, together they quickly warmed up the atmosphere and the Earth became a real hell.

The vast majority of dinosaurs and many other terrestrial organisms were in the affected area.

Having escaped a tsunami or earthquake, they could die after several hours of intense heat.

The planet, formerly covered with forests, caught fire almost instantly.

About 75% of living things were destroyed, including any mammals weighing more than 25 kg.

Acid rain acidified the oceans, and half of the plant species died immediately or within hours.

The soot from the fires, combined with the impact dust, blocked the sun's rays. The earth was deprived of sunlight for about a year, which greatly influenced the climate.

Some plants that managed to survive the impact eventually also died, and after them, miraculously survived large herbivores, and then carnivores.

Aquatic ecosystems have also collapsed, but not completely. For example, turtles and crocodile ancestors managed to survive.

Some researchers call the environment of that time Lunar, so desolate and barren it was.

It was almost impossible to survive in such conditions, and yet life on our planet did not stop.

All large animals died, and those who remained began to repopulate the Earth.

The first to come to life were foraminifera - single-celled organisms that appeared in the crater several years after the impact.

Then the ferns woke up, after just a millennium they were able to grow and occupy almost all of the vacated space. But for large mammals, such conditions were not suitable, there was not enough food, so only small animals wandered among the ferns, weighing no more than 600 grams.

There were few flowering plants and nutritious seeds in this world.

But after 100,000 years, mammals returned to the size of a raccoon. Ferns were replaced by palm forests, there was more food, the world began to gradually return to normal.

After 200,000 years, the so-called palm period gave way to the so-called pecan period. Of course, no pies were made then, but nut-like plants arose, which means that much more nutritious food appeared. Mammals have used this for their own purposes.

The variety of species has tripled. The largest individuals reached about 25 kg, this is the weight of a rather large beaver or gazelle.

Apparently, mammals evolved along with plants.

But before extinction, there were more species on the planet.

Finally, about 700,000 years later, legumes appeared, and this is much more important than it seems. Legumes worked like protein bars for ancient mammals, increasing the size of animals even further, and thus the diversity of species.

At this stage, the future owners of the planet weighed more than 50 kg, this is the weight of a modern large cheetah.

Ancient mammals became a hundred times heavier than their ancestors, who lived among ferns, and yet less than a million years have passed.

For a person and any other living creature this is a very long time, but for evolution it is nothing.

The oceans were recovering more slowly, scientists estimate that it took them about 3 million years.

Birds are considered by paleontologists to be one of the few surviving dinosaurs. Their non-avian relatives became extinct, but most of the lizards nevertheless adapted. Most likely, they were helped by the ability to dive, swim or seek refuge in water and swamps.

Many bird species can build nests on the ground. This helped their ancestors to cope with the horror that was happening around.

As a result, life on Earth returned to normal. Over time, this led to the emergence of people.

This would not have happened without the fall of that very asteroid. You can say. He became a trigger for human evolution.

But what happens if the catastrophe recurs? Well, you already know the rough plan. Most likely, most of humanity will not survive a new space attack, but our planet will surely recover. So life goes on".

#History #Space #Earth #In the world #World #News #Animals #Interesting #Science #Planet #Наука
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