Sunday, November 9, 2014

Colliding Continents

"Colliding Continents" is a movie by National Geographic. It's 50.04 minutes long. And it's about Plate Tectonics.
Mostly it's about the Plate Tectonics and its contribution to our Earth's Formation and speculation of what may happen next.

In this movie, National Geographic explained, in more detail, what we have learned in science class about geography. We didn't really learn a lot about the Creation of Earth but there's a lot about it in here. Earth was created by the explosion of a star. Pieces of the star floated around in space and crashed into each other thus creating the first base of Earth. Earth didn't have any water then or atleast until asteroids with water crashed onto Earth's surface thus creating the ocean though it was one at the time.
The Early Earth Blasted by Asteroids
After awhile, the blasting asteroids slowly stopped. Cratons formed out of the Earth and created 'Valbaara' and 'Ur'. Ur still lives on in our continents now but there were other supercontinents though the landmass containing Europe, Africa and Asia as well as the landmass of America are considered somewhat supercontinents. Rocks called Granite rose from Inside Earth to the surface and there are still more that are inside Earth.
The Rock Cycle
It seems that some actually are recycled. They go inside Earth and come back out later. The continents are constantly moving. Most of the continents are plates. Of course countries are also plates such as India. The lava of volcanoes harden and can create igneous rock or granite and thus the first step of the rock cycle that can lead to sedimentary and metamorphic rock. People predict that our world will transform into the state of Pangaea [now Pangaea Ultima] once again and the climate will be very cold. Due to the clashing plates, many buildings on the coasts will fall and earthquakes as well as volcanic eruptions and other natural disasters will occur.

I am very much interested in the first Super-Continents. It's fascinating; the way Earth was created, the long period of time that it took to actually come to be as it is now, the forming of the layers and most importantly the first super-continents themselves. Sutton in 1963 was the first to ever come close to formulate a super-continent cycle.  His chelogenic cycles were about continents clustering together irregularly however it was a bit wrong. The Theory of Tectonic episodicity was supported by Wilson in 1966 and is now known as the Wilson Cycles. Hallam in 1974 showed how sea levels were connected to this. Now, Super-continents are continents smashed together to put it simply. The landmass of Europe, Africa and Asia is a super-continent. America is also arguably one. The most recent supercontinent and also the most known one is Pangaea. People forget that Pangaea is merely the latest of a line of supercontinents. We'll start from the begining. First cratons [large giant rock cores] rose up on the surface.
Timeline of SuperContinents
The oldest supercontinent, "Ur" was created by one of the two cratons. The second oldest supercontinent was called "Valbaara" and was created by the second craton. Now "Ur" lives on in India, Madagascar and Australia and is now the oldest landmass ever. Next came Kenorland. Kenorland broke up a few billion years ago and created a massive spike in rain and along with the Sun at 85% of its true power, created a Earth with freezing temperature. The first 'proper' supercontinent was Columbia which formed around 1-2 billion years ago. Rodinia formed about a billion years ago using Columbia's remains which were in ruins. There were no animals or plants in the other supercontinents' time but in Rodinia, there were animals and plants in the sea. The destruction of Rodinia caused sea levels to fluctate and thus helped animals and plants get on land. Unfortunately, it also created a snowball Earth like Kenorland. Luckly there were volcanoes in the time of Rodinia's destruction and pushed rich nutrients into Earth's surface which is good for living organisms.. Of course after that came Laurasia and Gondwana and after that Pangaea.

The video was excellent. It is especially good for someone who is studying Geology and mostly for students and teachers. In fact, it has more detail than textbooks and it has information from geologists. It has extremely reliable information and facts. And it explained many concepts and then used to reason what happens in Geology.
It started from the begining of Earth and ended at the Geological future of Earth. The movie also had good graphics that showed what they were trying to say though it could use more improvement. It had certain images that were not obvious as would have been best. This movie was a detailed summary by National Geographic for me.

Link to MindMap:  https://docs.google.com/a/rism.ac.th/drawings/d/1fcR92RU12XY3VADe7-nQNAZqfMdNlwzIWX6rgjRKSSk/edit?usp=sharing


Sources:

-Wilkins, Alasdair. "A History of Supercontinents on Planet Earth." Io9. N.p., 27 Jan. 2011. Web. 03 Nov. 2014. <http://io9.com/5744636/a-geological-history-of-supercontinents-on-planet-earth>

-Nance, R.Damian, and J.Brendan Murphy. "Origins of the Supercontinent Cycle." Science Direct. China University of Geosciences (Beijing) and Peking University. Production and Hosting by Elsevier B.V, 8 Jan. 2013. Web. 07 Nov. 2014. <http://www.sciencedirect.com/science/article/pii/S1674987112001570>.

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