Saturday, 31 May 2014

The Chicxulub Crater

Sixty-six million years ago at the end of the cretaceous period an asteroid struck the earth in a location that is now known as the Yucatan peninsula, Mexico. It is one of the largest known impacts that earth has ever received and has been held responsible for the extinction of three-quarters of the earth's plant and animal species at the time. This gargantuan crater sits grandly off the coast of Mexico, and is a worrying reminder of the power and unpredictability of our solar system. It is known as the Chicxulub crater.

The Chicxulub crater is more than 180 km (110 miles) wide and 20 km (12 miles) deep, and the asteroid that formed this crater is calculated to have been the size of Mt Everest. If you were to dive off the side of the crater and hold a classic skydiving belly-to-earth position you would reach terminal velocity - roughly 195 km/h or 122 mph - and would fall for roughly four-minutes before you impacted with the ground below. When the asteroid hit earth, its impact released the equivalent of 100 teratons of TNT. In contrast, the most powerful man-made explosion was that of the Tsar hydrogen bomb which was detonated in the Novaya Zemlya archipelago on 30th October 1961. This bomb released the energy of 50 megatons of TNT, meaning that the Chicxulub asteroid impact was two-million times more powerful than the Tsar hydrogen bomb. It was so powerful, the impact killed every single land dwelling dinosaur on the planet through the production of simultaneous mega tsunamis, global earthquakes, wildfires and volcanic eruptions. The dust and particles released from the burrowing of the asteroid may also have covered the entire surface of the earth for up to a decade. However, some theorists believe that the Chicxulub asteroid was a blessing in disguise - at least for the human species. As this impact altered the conditions of earth, which later enabled homo sapiens to thrive.

There have been numerous asteroid impacts on earth ranging from extremely large to extremely small. In fact, small asteroids with a diameter of approximately four meters hit the earth roughly every 1.3 years. Whereas larger asteroids with a diameter of roughly 1,000 meters hit the earth roughly every 440,000 years. If an asteroid has a diameter of less than one meter then it is called a meteoroid; and they seldom make it to the ground due to burning up in the earth's atmosphere. You may also like to know that there are no near earth asteroids (NEA's) large enough to cause the demise of the entire human race in a single blow, and if an asteroid of this size were to head for earth, we would have months of notice thanks to the space agencies that are constantly looking to the stars - I'll let you decide whether knowing that a pending catastrophic asteroid impact is looming, is a good or a bad thing. However, if a smaller NEA were to head for earth - just as asteroid 2005 YU55 did at 18:28 on Tuesday 8th November 2011, which was the size of a military aircraft carrier and passed closely between the earth and moon - then there would be almost no notice. And if the asteroid were large enough it could release so much energy upon impact that it could alter the earth's climate so severely that crops may not grow for years, therefore, causing mass starvation.

Earth is nothing more than a snooker ball in a galaxy sized game of billiards, and one thing we know for sure is that one day, a large asteroid will hit again. The question is, when?

The main asteroid belt within the Milky Way. Many of these asteroids could strike earth with no notice, causing mass damage to the earth and its inhabitants.


An artists impression of the Chicxulub crater. The asteroid that formed this crater was the size of Mt Everest and is famously known as the asteroid that killed the dinosaurs.


A photo of the Tsar hydrogen bomb explosion from 30th October 1961. This explosion is two-million times weaker than the Chicxulub asteroid impact.


The Chicxulub crater location.

- Until the next Butterfly...

Friday, 30 May 2014

Tsunami

The word 'tsunami' means 'harbor wave' in Japanese (tsu = harbor + nami = wave), reflecting Japan's rather uncomfortable tsunami-prone history. Usually caused by earthquakes, tsunamis of this nature have been known to reach heights of over 100 ft and travel at speeds of up to 500 miles per hour - almost as fast as a passenger airline. They are one of the most destructive forces in nature, and have claimed many lives and much havoc over human history.

Most tsunamis occur within a geographical area known as the 'ring of fire'. The reason for this is that there are numerous earthquakes and volcanic eruptions within this area. The ring of fire is a large 40,000 km - 25,000 mile - horseshoe-shaped area that encompasses most of the Pacific ocean. It contains a continuous series of ocean trenches, volcanic arcs and volcanic belts; has 452 volcanoes, and is home to 75% of the world's active and dormant volcanoes. Around 90% of all the world's earthquakes and 81% of the world's largest earthquakes occur within the ring of fire.

When a tsunami is born it can travel across an entire ocean. In the deepest parts of the ocean a tsunami can be very small, sometimes only a few meters high, meaning that fishing boats and other vessels can sail over the top of a tsunami without ever realising. However, tsunamis retain their energy, meaning that it is possible for them to cross entire oceans without loosing a single drop of force. Although Japan is highly prone to tsunamis, Hawaii is also a favourite destination for these huge waves. Hawaii is hit by a tsunami roughly once per year, and receives the full blow of a sever tsunami approximately every seven years. In order to place the power and possible destruction of these natural disasters into context: in 2004 there was an earthquake in the Indian Ocean that emitted the power of 23,000 atomic bombs. This caused numerous tsunamis that slammed into the coastline of eleven countries and killed 283,000 people.

As if the threat of a tsunami was not terrifying enough; there is also such a thing as a 'mega tsunami'. As was stated earlier most tsunamis are caused by earthquakes, and due to the limited power of earthquakes tsunamis will usually only achieve a certain maximum size - approximately 100 ft. However, if a large landslide occurs then extremely large quantities of rock can fall from incredibly large heights into vast bodies of water with relentless force, and cause a mega tsunami. Mega tsunamis are very rare but they still happen more frequently that one would like to accept. On 9th July 1958 an earthquake with a magnitude of 7.7 - 8.3 caused 90 million tonnes of rock and ice to fall into the deep water of Lituya bay, USA. The impact from this collision was great enough to create a tsunami 1720 ft - 524 m - high. Howard Ulrich and his son witnessed the mega tsunami as they were sat in the bay in their fishing boat. I have no doubt it was with much apprehension that they watched this beyond gargantuan wave approach them, and carry them like a feather in the breeze over the trees. Amazingly, they both lived to tell the tale. However, mega tsunamis are not only caused by large landslides, it is also possible for them to be created via asteroid impacts. Roughly 66 million years ago an asteroid collided with the earth, creating the Chicxulub crater in Yucatan. This collision was so grand scientists have calculated that a mega tsunami as high a 5 km - 3.1 miles - was created. A wave so large that it could consume an island as big a Madagascar without much difficulty. A wave so vast that even attempting to visualise its grandness is difficult.

A peaceful looking Lituya bay, USA where the 1720 ft mega tsunami occurred on 9th July 1958.


An artist's impression of a mega tsunami about to hit the coastline.

A model recreation of the Chicxulub crater, Yucatan. This crater was formed by an asteroid that created a tsunami 5 km high.

The infamous ring of fire that contains 452 volcanoes and is the birth place of 81% of the world's largest earthquakes.

- Until the next Butterfly...

Thursday, 29 May 2014

Lungs of the Earth

The Amazon rainforest - also known in English as Amazonia or the Amazon Jungle - sprawls over a vast expanse of 5,500,000 square km (2,100,000 square miles) and graces nine countries. These countries are Brazil, Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. There are parts of the Amazon where no human has ever set foot, and it is home to the largest river on our planet.

It is estimated that the Amazon is home to 390 billion trees - including chocolate, Brazil nut and acai berry - which can be grouped into roughly 16,000 species. Scientific studies have been undertaken that suggest that there are approximately 6,000 tree species exclusive to the Amazon, with only 1,000 trees remaining per species. This may not appear to be of any initial interest, but imagine what these endangered trees could contain: a snack more heavenly than chocolate, a drug more potent than heroin or even the cure for diseases such as Cancer and HIV. All of a sudden, these 6,000 species of tree appear to have gained some significant value. The foliage of the Amazon is so dense that the forest floor is almost as dark as night. A minuscule 1% of available sunlight makes it through the leaves and onto the forest floor, making a walk through this natural maze highly treacherous. If you were to walk through the Amazon and gaze upon its raw wilderness - just as the British explorer Ed Stafford did in 2008 whilst undertaking a mammoth expedition that took 860 days (roughly two years, four months and ten days) to complete as he followed the Amazon river from mouth to mouth - you would find yourself within the company of 1/10th of the world's biodiversity. Some of which would consist of Jaguars, Cougars - not the type looking for playboys - Electric eels, Piranhas, Poisonous dart frogs, Tarantulas, Vampire bats and Anacondas, to name a few. The Amazon river is 6,400 km (4,000 miles or 1/6th of the earths circumference) long, and meanders through seven countries like a giant artery whilst reaching a maximum width of 190 km (120 miles) during the wet season of December to June. Despite all of the Amazon's beauty and uniquely diverse ecosystem it is not always treated with the respect it deserves, and deforestation has become a considerably large issue.

Deforestation is a large-scale problem that has stemmed from the human race's want for more and more. The Amazon rainforest's deforestation is so vast that the areas that have previously been logged can be seen by the naked eye from space. The Amazon was a protected area prior to the 1960's, meaning that no significant deforestation had ever been undertook. However, since the Amazon has been opened up for logging and cattle farming purposes it has reduced in size significantly. In this present day the Amazon is losing 1.5 acres per second due to logging; please take time to allow the significance of this statistic to fully sink in... The rainforest used to cover 14% of the earth's surface, yet today it now only covers 6%. It is estimated that the entire rainforest could disappear within the next 40 years. This means that potentially within your lifetime, the Amazon could disappear completely. The only place it will be found is within textbooks and historic online databases. This is not just a sad fact, but also an alarmingly sobering one. As previously mentioned, think of all the potential cures for diseases and other amazing and possibly life-saving things that could be found within the Amazon. If the Amazon disappears then the world will lose - at least - 6,000 species of tree and at least 1/10th of its biodiversity. Not to mention the mass reduction in carbon dioxide filtration and oxygen production. Of course the human species will not disappear with the rainforest; earth has other 'lungs' that can provide us with breathable air. Albeit there will be less to share due to a reduction in the number of living trees and an increasing human population. However, it will be a grave loss to the planet if the Amazon rainforest, the largest of its kind and the most bio diverse area on this earth becomes nothing more than a chapter in a book. And ironically so, possibly a book that the rainforest was destroyed to create.

An illustration of the harm caused via deforestation over the past 64 years, and the anticipated next 6 years.

The deforestation of the Amazon rainforest as seen from space.
 

4 beautiful animals whose homes are slowly being destroyed.

The journey undertook by Ed Stafford along the Amazon river that began on 2nd April 2008 and finished 860 days later on 9th August 2010.

- Until the next Butterfly...