Pages

Monday 5 December 2016

10 OF THE BIGGEST NATURAL DISASTERS IN EARTH’S HISTORY


wpsF0D0.tmp
10 of the Biggest Natural Disasters in Earth’s History
By Adrian Chirila,
Toptenz, 5 December 2016.

The Butterfly Effect principle simply states that, given enough time, whatever event, no matter how small, can and will have tremendous reverberations into the future. And when talking about past disasters, natural or otherwise, we always have to keep in mind that, even though devastating, they are part of what brought us here in the first place. Without them the world and everything in it would have taken a totally different turn, ending up completely different than it is today. The further back in time any particular event takes place, the more indirect influence it has on the present and future, altering them beyond recognition.

We may try to speculate on how things would have turned out if any particular disaster from our past didn’t happen, but the variables are so small and infinitely numerous, that we may never know the right answer. Similar to weather prediction (which is looking into the future, by the way), we can only make our best guess with the limited information we have. With this being said, let’s take a look at 10 natural disasters from our past, and maybe later imagine how the world would have looked like without them.

10. Outburst of Lake Agassiz, North America

wps17DD.tmp

Roughly 14,500 years ago the planet was beginning to emerge from its last Great Ice Age. And as temperatures began to rise, the Arctic Ice Sheet that gripped much of the Northern Hemisphere began to melt away. Fast forward 1,600 years, and what is now the middle of the northern part of North America (parts of North Dakota, Minnesota, Manitoba, Saskatchewan and Ontario) was under a huge proglacial lake, formed by melting water being trapped by a wall of ice or another natural dam. With an estimated area of 170,000 sq. miles, Lake Agassiz was larger than any currently existing lake in the world, and roughly the size of the Black Sea.

Then, for whatever reason, the dam broke and all the fresh water trapped there escaped into the Arctic Ocean via the Mackenzie River Valley. And even if the deluge itself was bad enough, what followed next may be what killed off the megafauna in North America, as well as the Clovis culture. As the insane amounts of fresh water flooded the Arctic Ocean, it severely weakened the Atlantic “conveyor belt” by 30% or even more. This belt cycles warm water up to the Arctic, where it cools, sinks to the bottom and travels back south along the ocean floor. With the new influx of fresh water from Lake Agassiz, the cycle slowed down and the Northern Hemisphere returned to near-glacial temperatures and conditions for about 1,200 years, in a period known as The Younger Dryas. The end of this period, roughly 11,500 years ago, was even more abrupt than when it first started, with temperatures in Greenland rising by 18 degrees Fahrenheit in a just a mere decade.

9. The Siberian Traps Eruption, Central Russia

wps9441.tmp

Some 252 million years ago, planet Earth looked a lot different than it does today. Life was as alien as life can get and the continents were all pushed together, forming a single, super-continent known as Pangaea. Then, as if out of nowhere, all of it would change in a geological instant. In the far north of Pangaea, in what is now Siberia, a super volcano of Biblical proportions began to erupt. The eruption was so massive and so devastating, it covered an area of almost 1.7 million sq. miles (roughly the size of the continental US) in a one mile deep sea of lava. Only about 500,000 sq. miles of it are still visible today, in a region now called “The Siberian Traps.

This eruption itself and subsequent lava flows, while devastating in their own right, were only a catalyst for an unstoppable chain of events that would kill off 75 percent of life on land and over 95 percent of all marine creatures. This apocalyptic event marked the transition between the Permian and Triassic periods, and is sometimes known as The Great Dying. The immediate effects of the super volcano completely devastated the Northern Hemisphere, turning the air into literal acid and plunging the entire food chain into complete disarray. With the several century-long volcanic winter that followed, 10% of the world’s species had perished. After the dust settled, the planet was immediately thrusted into a massive global warming, raising the global temperatures by 5 degrees Celsius and killing another 35% of all land creatures.

The oceans were next, with much of the CO2 in the atmosphere being absorbed by the water and turning it into carbonic acid. With the increasing temperatures, the oxygen-depleted waters from the ocean floor began to expand and rise from the depths, trapping all marine life “between a rock and a hard place.” The massive amounts of methane hydrate, found even today on the ocean floor, began bubbling to the surface due to the warming waters, and raising the planet’s temperatures by another 5 degrees Celsius. At this point in time, almost all of marine species had died off and only the sturdiest of land creatures managed to survive. This event is the single largest case of a mass extinction to have ever happened on Earth. But at this point we are able to generate four times as much CO2 into the atmosphere as that super volcano all those million years ago, with most of the above mentioned effects already beginning to happen.

8. The Storegga Slide, Norwegian Sea


Some 8,000 years ago, 60 miles off the Norwegian coast to the north, a huge chunk of land roughly the size of Iceland broke off of the European continental shelf and plunged into the depths of the Norwegian Sea. Most likely caused by an earthquake that destabilized the methane hydrates found trapped there, the 840 cubic miles of sediment spread itself over 1,000 miles into the abyssal plain below, covering an area of about 36,700 sq. miles. The ensuing tsunami following the landslide wreaked havoc on all surrounding landmasses at that time.

As the planet was emerging from a previous Ice Age, sea levels were 46 feet lower than they are today. But even so, sediment deposits originating from the Storegga Slide have been discovered 50 miles inland in some places, and 20 feet above current tide levels. With waves exceeding 80 feet and travelling in all directions, Scotland, England, Norway, Iceland, Faroe, Orkney and Shetland Islands, Greenland, Ireland, and the Netherlands were all severely affected by this natural disaster. The last remnant of land that once connected the British Isles to mainland Europe, known as Doggerland, was completely swept over by the deluge, thus creating the North Sea we know today.

This was not the first or the last time this happened, with several other smaller landslides off the Norwegian coast taking place between 50,000 and 6,000 years ago. Companies involved in petroleum and gas exploration take special precautions so as not to trigger another such event by accident.

7. Laki Eruption, Iceland

wps2670.tmp

Iceland sits directly on top of the Mid-Atlantic Ridge where two large tectonic plates are pulling away from each other. This makes the island nation one of the most volcanically-active regions in the world. In 1783, an 18 mile-long crack on the island’s surface, known as the Laki Fissure, ripped open. Along its length, 130 craters formed, spewing 3.4 cubic miles of basaltic lava over a period of 8 months. Incomparable in size and devastation with what happened in Siberia 252 million years ago, the Laki event featured very similar characteristics, and was the largest volcano eruption of the past 500 years. Thanks to a network of underground tunnels known as lava tubes, the molten rock was able to spread hundreds of miles away from the fissure and raze a total of 20 villages to the ground.

The most devastating effect of Laki however was not the lava itself, but the toxic gases it spewed into the atmosphere. An estimated 8 million tons of hydrogen fluoride and 120 million tons of sulfur dioxide were released, poisoning the air and forming acid rains. Three quarters of Iceland’s sheep and over half of all its livestock died as a result. Due to starvation and disease, over 20 percent of Iceland’s population was killed over the following months. Furthermore, the sulfur dioxide was spread over much of the Northern Hemisphere, blocking the sun’s rays and plunging the planet into a mini volcanic winter. Europe was most affected by it, causing crop failures and starvation, leading to the infamous French Revolution.

The rest of the world is affected as well. North America experiences the longest and harshest winter on record, one sixth of Egypt’s population dies of starvation, and the monsoon seasons are thrown into disarray, affecting regions as far away as India and Southeast Asia.

6. The 2011 Tornado Super Outbreak, Central United States

wpsA6FB.tmp

Tornadoes in general leave few remnants of their existence over long periods of time. Their effects can be devastating, but from an archaeological point of view, not much evidence can be unearthed. However, the biggest and most destructive tornado event in recorded history took place in 2011 over an area colloquially known as “tornado alley” in both the US and Canada. From April 25-28 a total of 362 tornadoes were reported and confirmed across 15 states by the National Weather Service. Violent tornadoes occurred each day, with April 27 being the most active, with a record of 218 tornadoes touching down. Four of these were classified as EF5, the highest ranking possible on the Enhanced Fujita scale. On average around the world, one such EF5 tornado is reported once a year or less.

In total, 348 people were killed as a result of this outbreak, 324 of which were direct tornado-related deaths. The other 24 casualties were caused either by flash floods, fist-sized hail, or lightning strikes. Another 2,200 people were injured. The most affected state was Alabama, with 252 fatalities. The hardest-hit area was the city of Tuscaloosa in Alabama, where one EF4 tornado, with a diameter measuring nearly 1 mile and wind speeds exceeding 200 mph, ravaged through residential areas of the city. Total material damages have been calculated to be around US$11 billion, making the 2011 Super Outbreak one of the most expensive natural disasters to grip the US.

5. The Spanish Flu, All Over the Globe

wps29D8.tmp

As the world was gripped by the horrors of WWI, an even deadlier killer was beginning to make its presence felt throughout the planet. The Spanish Flu, or Influenza, was the deadliest pandemic in modern history, with 500 million people infected worldwide - about a third of the population - and an estimated 20 to 50 million people killed in less than six months. Around a quarter of all US citizens became infected and 675,000 of them died because of it, lowering the average life expectancy by 10 years. As the First World War was slowly drawing to a close in 1918, the Influenza virus was given little attention at first, especially on the battlefield, which quickly became a perfect hotbed for the airborne disease.

For years, scientists believed the origins of the flu began in the trenches of France, and neutral Spain was conducting heavy research on it, earning it the name “Spanish Flu.” The harsh conditions of the battlefield were perfect for such a disease to be created, with large numbers of people being packed together in squalor and often times in close proximity with animals such as pigs. Moreover, the many deadly chemicals used throughout WWI gave ample chance for the virus to mutate.

A decade after the war, however, Kansas was being seriously considered as another possible breeding ground for the N1H1 influenza virus, when it was discovered that 48 infantry men died in a military camp there. More recent evidence indicates to a group of 96,000 Chinese laborers who were sent to work behind the British and French lines. Reports of a respiratory illness that struck northern China in November 1917 was identified a year later by Chinese health officials as identical to the Spanish flu. However, no direct link had been made between the Chinese illness and the worldwide outbreak. The effects of the pandemic can be felt even to this day, 100 years later, with several other related strains of the virus hitting in 1957, 1968 and again in 2009 and 2010 during the “swine flu” crisis. None of these instances have been as deadly as the one at the end of WWI however, when only the isolated Marajó Island in Brazil’s Amazon River Delta had not reported an outbreak.

4. Last Outburst of Lake Agassiz and the Black Sea Deluge, Eastern Europe

wpsD31A.tmp

Once again Lake Agassiz makes it on this list, this time with its final drainage which occurred around 8,200 years ago. After the lake’s last major drainage mentioned above, the ice sheet replenished itself due to the cooling caused by the lake’s fresh waters gushing into the Arctic Ocean. But as the planet began to warm up again 1,200 years later, the lake reappeared. But this time Agassiz seems to have merged with another equally large Lake Ojibway. The joining was short lived, however, with their complete drainage taking place, this time into Hudson Bay. Like before, the planet was plunged into another cold spell, called the 8.2 kiloyear event. However, this event was far shorter than the Younger Dryas, lasting for only about 150 years. Nevertheless, this sudden supply of water into the world ocean, raised sea levels by a staggering 13 feet.

Major flooding took place in all corners of the world, from the Americas, Europe, Africa, Arabia, South Asia, and the Pacific Islands. Many submerged settlements have been found all over the world, which seem to date from this period. This time in history may also be when all the Flood Myths around the world came into being. But the biggest case of flooding came about in Eastern Europe’s Black Sea, which at that time was no more than a fresh water lake. With the fast sea level rise, the Bosporus Strait partially gave in and water from the Mediterranean poured into the lake to form the Black Sea. The speed at which water poured in is still debated to this day, as is the quantity. Some believe that over 10 cubic miles of water entered the strait with 200 times the flow of Niagara Falls. This lasted for three centuries and flooded 60,000 sq. miles of land, with waters rising by six inches per day. Others believe the flooding was more gradual and covered just 770 sq. miles.

3. The Zanclean Flood and the Mediterranean Sea

wps64BC.tmp

Just like the Black Sea above, the Mediterranean was also a lake once. As the African and Eurasian tectonic plates moved closer and closer together over a course of many millions of years, they eventually collided. Their initial point of contact was between the Iberian Peninsula and the northern coast of West Africa some 5.6 million years ago. Isolated from the Atlantic Ocean, the now Mediterranean lake began to evaporate due to the arid conditions over the course of several hundred thousand years. In most places the sea floor was covered by a mile-high layer of salt. This salt was then blown by the winds, wreaking havoc on the surrounding landscape.

Luckily, 300,000 later the Mediterranean was full once again. The likely cause is believed to have been the continuing shift of the crustal plates, which in turn caused the ground around the Gibraltar Strait to subside. Over the course of several thousand years, an instant in geological terms, the Atlantic dug its way through the 124-mile-long channel. The flow of water reaching the Mediterranean basin was slow at first, but still three times the rate of discharge of the Amazon River today. However, it is believed that once the channel was wide enough, the surge of water was tremendous, filling the remaining 90% of the Mediterranean basin in a course of several months to two years. The water level rise may have been as high as 33 feet per day. This event is known as the Zanclean Flood. And even today, more than 5 million years later, the Mediterranean is much saltier than the Ocean, due to the narrow strait that connects them.

2. North China Drought, 1876-79

wps4569.tmp

Between 1876 and 1879 a serious and large-scale drought occurred in China, leaving some 13 million people dead out of the total of 108 million. As the world was emerging from its last period of cooling known as “The Little Ice Age,” a drought in the Yellow River basin area began in earnest in 1876, worsening the following year with the almost total failure of rain. This was by far the worst drought to hit the region in the past 300 years, and definitely caused the largest number of casualties. Shanxi province was the most affected by the famine, with an estimated 5.5 million dead out of a total population of 15 million.

This was not the first time China was faced with a severe drought, and up until the 18th century the nation was heavily invested in the storing and distribution of grains in cases of dire situations such as this. In fact, the state on several occasions was effective in preventing serious droughts from resulting in mass starvation. This time however, the Qing state was considerably weakened by the mid-century rebellions and strong British imperialism, and was totally unprepared for a crisis on this scale. Foreign and local relief efforts had been made, but much of rural China had been depopulated by starvation, disease and migration.

1. The (Hypothetical) Collision Between Earth and Theia


Though this list was not written in any particular order, we’ve decided to end it with a huge, cataclysmic event of literal astronomic proportions, which made our planet what it is today. And even if scientists are not 100 percent certain it happened, there are strong indications that it did. Some 100 million years after our planet had been formed by the gradual collection of asteroids and other space debris, the young Earth was headed on a direct collision course with Theia, a hypothesized planet in our young Solar System. This other planetary-mass object is believed to have been roughly the size of Mars, or somewhat smaller, and which 4.31 billion years ago was flung towards Earth and smashed head-on into it.

The force of the impact merged the two planets together, forming the Earth we know and love today. The pieces that were blown out from the collision were captured by the planet’s gravitational pull and slowly formed the Moon. The large size of our natural satellite relative to Earth backs up the collision hypothesis. Moreover, scientists analyzing moon rocks from three Apollo missions have compared them to volcanic rocks found in Hawaii and Arizona and discovered no difference in their oxygen isotopes. Another indication of the collision is the unusually large core and mantle of our planet compared to the other rocky worlds in our Solar System, as Theia’s core and mantle mixed with Earth’s.

Top image: The Laki fissure in Iceland. Credit: Chmee2/Valtameri/Wikimedia Commons.

[Source: Toptenz. Edited. Top image added.]

No comments:

Post a Comment

Please adhere to proper blog etiquette when posting your comments. This blog owner will exercise his absolution discretion in allowing or rejecting any comments that are deemed seditious, defamatory, libelous, racist, vulgar, insulting, and other remarks that exhibit similar characteristics. If you insist on using anonymous comments, please write your name or other IDs at the end of your message.