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Catastrophe - Episode 2 - Snowball Earth

May 31, 2021
Londyn its people the people who built it in fact all life on

earth

is here just by chance 99% of all species that ever lived have been wiped out in a series of

catastrophe

s that changed the course of evolution 650 million ago years ago the

earth

froze pushed life to the brink of extinction but if it hadn't then life today would be little more than a microscopic slime this is the story of the Earth

snowball

ing when we think about how we evolved from being individual cells We tend to see what we are today as a fairly calm process, don't we, with animals slowly transforming into other animals, but that's only part of the story.
catastrophe   episode 2   snowball earth
The reality is far more brutal and violent, with creatures clinging to their lives as disaster after disaster threatens them with extinction. It is almost impossible to comprehend the immense time scale of our planet's life, so let's imagine the entire history of the Earth compressed into a single day. Each minute represents about 3 million years at midnight on our clock. Four and a half billion years ago the planet was born. Two minutes later, the first

catastrophe

struck a protoplanet, Thea, which crashed into the nascent Earth and, in its wake, the first life appeared. At 8:00 a.m. m., there were shallow seas filled with simple bacteria.
catastrophe   episode 2   snowball earth

More Interesting Facts About,

catastrophe episode 2 snowball earth...

Gradually, over the next 2 billion years, the planet stabilized although life remained. as single-celled organisms until 12 and a half hours later, at 8:27 p.m. 650 million years ago disaster struck again the planet froze temperatures plummeted I spread from the polls encased the planet in a layer thousands of meters thick a

snowball

life on Earth had barely begun now it seemed friend there is no Traces of these ancient ice sheets left there have long since disappeared, but there are still clues that can tell us about this dramatic ancient Ice Age. The evidence is hidden in some of the most remote places in the world.
catastrophe   episode 2   snowball earth
These are the Flinders Mountains in outback Australia. Today it is one of the hottest and driest. places on Earth, but geologist Jim Geylang knows that the rocks here provide direct evidence of our planet's frozen past. The area is so vast that the best way to investigate is from the air. There is a history of disaster written in these rock layers. You just have to know how. reading it is really like looking at a book made of rock, each layer has a secret. We look at these rocks as if they were a history book, with the help of aerial photographer Tim Buyer, they see an unusual rock formation in a Dry-up Creek is evidence that the scales have been searching for a 650 million year old rock called tumbled stone .
catastrophe   episode 2   snowball earth
A tumbled stone is a piece of exotic rock that should not be mixed with mud and sand, they should be together in boulder or gravel offerings. beds, but there they are, the rock may seem insignificant, but it is an important clue to the powerful forces that created the frozen world of snowball land. This rock should not be here, it is sitting on a rock composed of mud, silt, sand and gravel, and normally that is impossible. everything now is one big rock, there is only one force that can transport rocks like this around the world and that is ice.
There isn't much ice in Australia today, so to investigate how ice might have moved rocks around the world in the ancient past. Glaciologists Shadow Neil scales the sheer walls of Alaska's Matanuska Glacier, the closest we can get to our distant frozen past. We are taking a look at the rocks that the glacier transports down the valley and to do that we need to go down there glassy it is not natural bulldozers crush everything in their path tear stones and rocks from the top of the mountains and carry them down the valley rocks as big as Buses can be transported for miles across the landscape by a glacier.
The longest glaciers are hundreds, if not thousands, of kilometers long, so you can move rocks long distances. When ice melts, it deposits debris at the base of the glacier. This glass is only a few hundred meters thick, but can still carry thousands of tons of rock. The glacier brought all these things down from the mountains and when the glacier melts it ends up looking like a construction site that has been washed away. The Matanuska Glacier carries rocks for more than 24 miles. It's the same process that carried ancient stones in the Flinders Ranges, but they were transported thousands of miles by glaciers 650 million years ago.
Here is a great example of a rock that was picked up by the glacier, carried down the valley and then deposited much like you would find in Australia where glaciers used to be. In the past, outback Australia was once covered in ice, but that doesn't prove the entire world was frozen. The problem is that the Earth's surface is constantly moving very slowly pushing the continents to different places, so it is possible that 650 million years ago. Long ago, when the stones were deposited, Australia could have been much closer to the cold South Pole, meaning the stones were transported by normal polar glasses.
The solution to this riddle can be found in another desert, Death Valley, in the southwestern United States. The term Snowball Land was coined by geologist Joker Shink, who has been gathering evidence for the theory during the decades. last two decades. Death Valley has a number of rocks that are extremely important to understanding Earth's history. It's a treasure chest like the Flinders Ranges. It's not the kind of place you'd expect. to find evidence of ice, but geologists have found dozens of glacial stones here. Every time I come here I see new things there, those big rocks and I see one at the bottom and they are all stones, you can see they are coming.
From the top, this is one of the best places in the world to see this type of geology. The fallen stones that Kersh Pink has discovered here date from the same period as those found in the interior, so this desert was also covered in ice, but the big advantage is that we know where Death Valley was six hundred and fifty million ago. of years. Each rock has a unique magnetic signature, allowing scientists to determine the point on the globe where the rock formed to study this signal that Kirsch Fink drills cause in rocks. that contains the fallen stones and measures their magnetic field the Earth's magnetic field is formed by electrical currents that flow in the middle of the planet the pattern of that field allows us to measure the latitude that forms Iraq that when a glacier throws these fallen stones here Death Valley was within the tropics, the results of the Flinders Ranges were even more dramatic.
A group started studying magnetism in the Flinders Ranges and thought they had a very stable magnetization. He said, well, wait a minute, something might be relevant there, the magnetic signal from the rocks revealed. that 650 million years ago Australia was in a completely different place than today when the entire continent was under a big freeze Australia was close to the equator here was the proof that scientists were looking for it was wonderful it was the first time anywhere that it was proven that The glaciers were in the ice caps of the equator, along the equator the warmest climatic zone in the world meant only one thing: if there is ice at the equator, then the entire planet must have been covered in ice, so there is Scientists on the white planet believe it was the largest ice age in Earth's history.
The entire Earth would have looked like Antarctica looks today. Even desolate areas like this in Death Valley with nothing would be under several hundred meters of ice. All the planet. In fact, it would be a snowball under a thick crust of snow and ice. The simple microbial life that develops in the oceans faced an uncertain future. This was the greatest ice age this planet has ever known. You have to imagine a planet whose oceans do not exist. They will only be covered with ice near the poles, but I said that it spread throughout the planet and practically turned off its living systems. 650 million years ago life on Earth seemed destined for total extinction, somehow something had plunged the entire planet into a catastrophic freeze, the question was what 8:27 p.m.
In our watch of Earth's history, 650 million years ago, the planet faced a climate disaster, a global freeze, but what made this happen, the Earth as a snowball was not the first time the Earth froze and it wouldn't be the last time our planet goes through an ice age about once every hundred thousand years most of them are caused by changes in our orbit the further we get from the Sun the colder it is at the height of the Last ice age ice sheets covered about 1/3 of the planet and all of this would have been buried under hundreds of feet of ice, but factors like orbit and rotation are not enough to explain the eye's extension to the equator. , which must have taken something much more dramatic.
The smoking gun turned out to be our atmosphere, specifically a greenhouse. Gases like carbon dioxide, a greenhouse gas, is any type of gas that has the ability to convert the sun's rays into heat, making this planet the warm planet it is today, but it is a delicate balancing act if CO2 levels rise or fall too much in the climate. spirals into chaos too much carbon dioxide and the planet warms too little and cools carbon dioxide is a very important gas it is both our dilemma and our solution when it is there in two greater proportions that overheats the earth, which Of course we were worried today however In the time before Snowball Earth we had the opposite problem: there was not enough carbon dioxide and the Earth began to cool to a point where there was uncontrolled cooling that locked this Earth in an icy crust.
Carbon dioxide levels caused the Snowball Earth disaster. Something was removing CO2 from the atmosphere on a large scale and there is only one process capable of doing it. Erosion of carbon dioxide mixes with water vapor to form acid rain. The acid reacts with the rocks it falls on. It forms new carbon chemicals in the water, which then reaches the sea, where it helps form solid limestone. Carbon dioxide that was once in the atmosphere becomes locked in the ocean floor when erosion occurs at high speed. Rocks are washed away with acid rain and it pulls carbon dioxide out of the atmosphere and ensures it is locked in the ocean.
Erosion occurs more quickly when it is hot and humid. Typically at least some of the Earth's land masses are too far north. or south for erosion to be a major factor, but 650 Million years ago, all of Earth's landmasses, from Death Valley to Australia, were grouped into a large supercontinent at the equator, the process of erosion accelerated, CO2 levels plummeted and so did the Earth's temperature. As a result, the Earth inevitably has to cool into a snowball. Today, plants and animals help balance carbon dioxide levels in the atmosphere. Plants absorb it. Animals exhale it, but six hundred and fifty million years ago the only form of life on Earth was one. cellular bacteria in the oceans and they were actually making the situation worse six hundred and fifty million years ago this is a world of cyanobacteria bacteria that formed a layer of slime on the bottom of the sea saina bacteria are tiny organisms that have existed on this planet for 3 billion years before Snowball Earth, but at this time they were particularly important, these cyanobacteria absorbed even more carbon dioxide from the oceans and locked it up in limestone reefs called stromatolites.
Some of this ancient carbon dioxide is still trapped in fossilized reefs like these in the Flinders Ranges in the south. Australia, when Jim Geylang applies a weak acid on them, the carbon dioxide that they locked up hundreds of millions of years ago bubbles up, what you will see is an effervescence, those white bubbles, the carbon dioxide that had been locked up in these traumatics is released again. atmosphere, instead of stabilizing carbon dioxide levels, cyanobacteria were depleting them further, in combination with weathering, they sucked carbon dioxide out of the atmosphere and temperatures plummeted, even then the planet could have avoided a complete freeze until a catastrophic chain reaction pushed it to the point of no return thirty seconds after eight twenty-seven p.m. on our clock of Earth's history, snowball Earth six hundred and fifty million years ago and The ice count was sliding down from the poles in a normal ice age at some point it would have stopped, but this was not normal for the ice to keep coming until it finally reached a point of no return as it triggered aphenomenon that would take life to the limit.
The Earth's surface is made up of land, open ocean, and ice. All of these surfaces reflect sunlight differently. and that's the key to what happened next this is the arctic ocean and the point where the ice meets open water scientists call it the leading edge and geophysicist don para vich is here to study how the ancient earth tipped over towards a catastrophic deep freeze this is the place where the ice frozen to the shore meets the open Arctic Ocean, but it is more than that the cable is where there is water the cable where there is light and that is why the cables were their life we ​​see pass whales and seals and birds flying above It's an incredibly productive area here for Vacanti or albedo of two very different surfaces: sea ice and the open ocean.
Its sensor measures the amount of sunlight that hits the ice and how much it reflects, since sea ice is the most reflective surface on the planet and reflects 85% of the sunlight that hits it, if we just went out just a hundred meters away from the leader, the albedo would be less than 10% and the interesting thing about this is that snow-covered ice has the largest albedo of any naturally occurring ice. The Earth's surface and the open ocean are the smallest, so here we have a contrast between the best natural reflector and the worst natural reflector. The open sea reflects very little light back into space, absorbs the energy of sunlight, and keeps the planet warm.
Six hundred and fifty million years ago the opposite happened. The best of the Earth. Reflecting sea ice was replacing its worst reflector, sea water. When enough ice had formed, the remaining ocean could not absorb enough heat, so more sea ice accumulated, reflecting more sunlight. , the Earth cooled and that produced even more ice, it was the point of no return. Let's say we grow a little more ice, so we replace the worst reflector with the best reflector that will cool things down, we will get more ice and it will get colder and create on itself a runaway freezing effect capable of changing everything.
Planet in an ice ball is an idea that no one considered until a few decades ago, scientists only discovered it was possible when they were studying another type of disaster: a nuclear war during the Cold War. Researchers predicted that a nuclear holocaust could pump enough smoke and dust into the atmosphere to block the Sun and start a global freeze. Russian climate modeler Mikhail Bedico was investigating the scenario when he made a chilling discovery: He calculated that if the ice sheets spread Beyond 30 degrees latitude, that is, as far south as North Africa, it would reflect so much energy from the sun that the Earth would reach an irreversible tipping point, so when we have a system like Earth's with these feedbacks, one of the things that is talked about a lot is turning points, you can think of it as if you are in the boat rocking back and forth there is not much change until you go too far and then you are in a new state and Bedico's work said that if we moved the ice down far enough it would reach a tipping point and cover the entire earth with it Boadicea calculated that if the ice ever reached this tipping point, the planet would no longer absorb enough heat to keep the ice under control, the planet would be buried in ice from pole to pole.
The theory is that 650 million years ago this is exactly what happened instead of the world we have today without something that looked like this, a vast white expanse of ice blocks tilted in all directions covered in snow, the planet descended to the most extreme and least hospitable weather he had ever experienced, finally the ice sheets collided holding their frozen layers together. With jaws locked at the equator, it seemed like nothing could survive in this frozen wasteland and yet incredibly it was this catastrophe that brought about life as we know it and without it none of this and none of the people around us would be here today 647 million years. 8:28 p.m. ago In our graph depicting Earth's history, the planet was buried under ice thousands of meters thick beneath the ice sheets.
Single-celled organisms, the only life on the planet, faced a difficult choice: adapt or die. The bacteria it evolved for 2 billion years seemed destined. Extinction Imagine if the snowball happened today, could we survive? Temperatures would fall well below zero. polar caps would extend from the poles and engulf entire continents. Violent snowstorms would paralyze entire populations. You couldn't run a nuclear power plant long enough to make it through the snowball for many years. Experts believe we could find ways to survive an ice age in the short term, but the chances of surviving a Snowball Earth are slim to none.
If humans ever experience a Snowball Earth, we will be bluntly out of control, there is no way we can stop it. It would probably be easier to live on the surface of Mars than on the surface of the Earth during a snowball without food to eat or fuel to keep us warm the ice that covers the planet would become our tombstone during a snowball the only beings alive were single Cellular bacteria even their survival seemed unlikely, but here we are, life clearly survived. The question is how the quest to learn how ancient organisms kept evolution alive has led this reclusive microbiologist to eliminate Glassier in southern Alaska.
Here Hazel Barton studies how life may have existed. He survived a global freeze his mission is to find signs of life and some frozen caves that look very dead people used to think that the caves were devoid of life that there was nothing in their returns they were actually full of microorganisms Barton searches for modern microbes living in this ice cave to learn how your ancestors endured the Ice Age six hundred and fifty million years ago. If you look at the edge of the cave, you can see all the dust particles that have lodged in the ice and create a surface that microbes can actually live in the cave that runs beneath the glacier within its minus four degrees.
Creatures that live in such harsh conditions are known as Extremophiles. Barton samples the microbes buried in icy rock sediments at the base of the glacier I'm looking at. for some settlements that could contain microbes and have never been exposed to heat, so what we remember about these insects is that they love charcoal and they have actually evolved to live in those cold conditions and so if I were to take them outside right now to die would be like taking us to the middle of the desert and leaving us there Barden believes this dark sub-zero cave may shed light on how microbes adapted to conditions during Snowball Earth Most surfaces exposed on Earth would probably have looked like this, so we're looking at the kind of conditions that organisms that survived that period would have lived in.
They don't just live on the ice, they live in it. Furthermore, sunlight penetrates a few meters into the ice wall and that is enough for microbes to flourish. We're still pretty close to the entrance here, so I think there's definitely a lot of solar energy and then enough for the cyanobacteria to grow and they're probably in the ice, they're living in the ice right now, the deeper Barton goes into the cave, darker and colder it gets, but even here life depends on this is a community that looks like Sano bacteria, they are incredibly resistant to all types. of the stress they can survive during snowball earth the ice was thousands of meters thick enough to block almost all sunlight, the microbes needed to stay alive barton finds similar conditions even deeper in the cave here there is almost no light at all, but even in this icy dark world, she finds that microbes thrive, so what we are seeing is our microorganisms that have to adapt and generate energy when there is no sunlight, so what they do is extracting energy from the very rock they are actually chewing. in the rock to extract that energy from the outside.
Barton examines the samples of it under a field microscope. She believes that these modern signs of bacteria have a similar structure to the ancient microbes that survived Snowball Earth. We are seeing signs of bacteria. There is a whole community living in that. Ice cyanobacteria are really these amazing organisms. They are very, very adaptable. They are one of the oldest forms of life on our planet. They can survive in really extreme conditions. Cyanobacteria have developed surprising survival mechanisms. If our cells freeze, they break down their walls if they freeze. They dry out, they die, but cyanobacteria have developed a cellular structure that prevents breakdown in some of the most extreme conditions on earth.
They have changed the structure of their DNA so that it is not damaged. If you took us and dried us then you know our DNA would be irreparable you do that to allocate bacteria Oh and you just add water a hundred years later and within a few hours it starts photosynthesizing again just like the Sun could cope with dry conditions, others could cope with the ice as the ice rolled over them, most microbes died, but the hardiest ones survived over time, evolving strains that thrived in the cold and darkness to become the ancestors of all living beings on earth.
Nowadays, everyone thinks of these global catastrophes as if they are going to end their own life and it is As if not, these microorganisms have been going through similar things for billions of years and they are adaptable and they change and then they fill the niche left behind. Barton's research shows that even in the most extreme conditions on ice in the dark. life is far from a hidden Mars-sized object, the planet, you know, life will continue on Earth and the events that we may think are catastrophic, just turn a new page and when we start to see a different form of life On Earth, the only reason we are here today is because life adapted and survived, but there is another puzzle.
We are here, but ice is not everything. That ice should have kept the planet so cold that it could never thaw again, and for 25 million years. Then something extraordinary happened at 8:35 p.m. In our clock of Earth's history, the planet's surface had been encased in ice for almost 25 million years, but at 8:37 something extraordinary happened: the ice sheets began to recede, something was warming the Earth, but it wasn't the Sun, believe it or not. What would save the planet was actually inside the Earth buried deep beneath the ice. This is Mount Augustine in the Aleutian Islands, one of the most volcanic regions on the planet.
Augustine has been active for more than 40,000 years and is still erupting today, volcanologists John. The power is here to study what it tells us about the end of the snowball Earth because volcanoes are the only things on the planet hot and strong enough to thaw a frozen world that last erupted in 2006, everything comes to play a hell of fire lies under the frozen Mount Augustine. surface during its last eruption, millions of tons of lava and ash exploded into the atmosphere, so the material spewed by the volcano actually grew, we are about thirty meters higher than the top of the volcano before the eruption.
This is one of the newest ones. Landing in North America, I use a field thermometer to take a reading just below the surface. We have a temperature of about 95 to 96 degrees Celsius, so the top of the volcano is still very hot if you wanted to cook some fries. some eggs, this would be exactly the place to do it, there is no doubt that Mount Augustine is hot, but it is hard to believe that a volcano, even one this powerful, could break through a layer of ice several thousand meters thick where we are Now, it has been covered with glacial ice.
Probably only 10 15 20 thousand years ago all this was under a glacier at that time when power examined volcanic rocks here he found evidence that 24,000 years ago an eruption broke through the ice there is absolutely no problem for a A volcano like Augustine or his neighbors erupted through a sheet of ice that could be several kilometers or several miles thick. We know it's possible because we've seen it happen in 1996, the Grímsvötn volcano in Iceland erupted through a glacier that made its way up. To the surface through a kilometer of ice the torrents of hot gases and ash opened a giant hole in the glacier, melting the iceand at a furious pace flash floods carrying 45,000 tons of water per second raged for hours, but on a global scale that is nothing when the entire world was frozen.
A few small holes wouldn't have made much difference. Fortunately, volcanoes have another formidable weapon in their arsenal. They spew more than just lava and rocks. They also produce enormous amounts of greenhouse gases. Carbon dioxide. It is one of the most dominant species. of gas coming out of volcanoes there have been times when we have certainly had thousands of tons per day coming out of this volcano. Mount Augustine is overshadowed by the volcanoes that broke up the snowball Earth's ice. Scientists believe that thousands of people vented billions of tons of carbon dioxide into the atmosphere over a period of about a million years, causing carbon dioxide levels to rise, reversing the depletion that created the Earth ball. of snow and tipping the scales in the opposite direction.
Carbon dioxide built up rapidly in the atmosphere until it reached a critical point where we had a super melt of the ice and that was the death knell for Snowball Earth. The carbon dioxide-rich atmosphere trapped sunlight. It increased temperatures and finally melted the ice after a 25-million-year freeze. Snowball Earth is over. the ice sheets receded something remarkable happened the biggest leap in the evolution of life the world has ever seen a leap that would take us directly into the oceans a few single-celled organisms had survived after the ice melted they began to change Dramatically abruptly 3 million years after Snowball Earth ended, the new warm climate triggered an evolutionary explosion; unlike any other single-celled bacteria, they evolved into multicellular creatures, the first complex organisms and ancestors.
For all animals, including us, it was the beginning of a new era. For life on Earth, Snowball Earth must have been the closest thing we had to the extinction of early life on Earth, and yet no creature survived and it can't be a coincidence that very shortly after the waning stages of this ice age across the Earth, To get the first large creatures, it really looks like that series of environmental catastrophes spawned the kind of biology that could give rise to multicellularity. The key to this evolutionary revolution was oxygen before Deep Freeze's oxygen levels were only 1% too low to support more complex systems.
Organisms after freezing levels shot up to 21%. Scientists suggest that the increase in oxygen levels was a result of Ice Age chemistry. During Snowball Earth, the sun's ultraviolet rays reacted with water molecules in the ice to produce a chemical called hydrogen peroxide when the ice finally melted. The hydrogen peroxide decomposed again, releasing huge amounts of oxygen into the air and oceans. The increase in oxygen levels provided the fuel for life to evolve from single-celled organisms to multicellular organisms. They don't look like March, they're just the size of pinheads, but These little creatures are the oldest multicellular fossils on the planet.
The first links in the evolutionary chain that eventually led to advanced animals and humans in the new oxygen-rich atmosphere. These creatures became more and more complex, from a few cells joined together to becoming large creatures. enough for separate groups of cells to assume different bodily functions over millions of years. These specialized groups of cells evolved into the first organs and that paved the way for increasingly larger and more complex anatomies in Australia. Jim Galing studies the fossil remains of the creatures that inherited the planet after Snowball Earth. after snowball earth we see a revolution in the history of life from the fossil record because for the first time we see creatures large creatures that anyone can see with the naked eye are the first animals on earth this primitive sea creature is one of The first complex multicellular organisms lived and died about 50 million years after the end of Snowball Earth.
It is absolutely complete, you can see its intestines, you can see the end of the head where they represent the segments and these incredibly thin segments simply envelop all the animals on the sea floor. the planet, including us, descended from creatures like this, you are looking at the first life forms that had cell patterns and body plans that were the same as ours, head, tail, belly and back, although our direct ancestors are not necessary . These are the first creatures that represent the line of biology that gave rise to us throughout the planet. Similar organisms were evolving making the leap from primitive to complex life.
They had been life on this planet for more than 3 billion years and it was really just the snowball event that started complex life if it hadn't been for this ice age this would have been a slime world forever and we wouldn't be sitting here talking about it so if you want to make a point in the story of life that made a big difference that was the earth like a snowball, from the slime to this complex life in all its vivid and colorful infinite glory, all of this, you, me, every living thing on the planet is here due to an evolutionary explosion 650 million years ago and a catastrophic freeze that threatened to wipe out all life on Earth, but ended up creating life as we know it.
If it weren't for Snowball Earth, we probably wouldn't be here in the next

episode

of catastrophe. Massive volcanic eruptions killed ninety. -five percent of all life on Earth in the biggest extinction of all time, but surprisingly this new catastrophe triggers the evolution of the most successful creatures to ever walk the planet: the dinosaurs.

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