Movements Beneath the Crust...
- The main theory regarding the earth changing is the ongoing process of plate tectonics. These tectonic plates will have a major effect on the Earth's shape within the next 200 million years and beyond.
- Even today in 2013, the tectonic plates are causing movements to the positioning of continents, but the movement is so small that it is not noticeable. The movement of the plates can vary from 1 centimetre to 10 centimetre per year. To put this into perspective, that is the growth of a human finger nail per year.
- Even today in 2013, the tectonic plates are causing movements to the positioning of continents, but the movement is so small that it is not noticeable. The movement of the plates can vary from 1 centimetre to 10 centimetre per year. To put this into perspective, that is the growth of a human finger nail per year.
Continental Drift...
Continental Drift was the theory created by a German meteorologist called Alfred Wegener. He proposed that the Earth did not always look the the same and has changed over many millions of years. He noticed that the coast lines of of Africa and South America looked as if they could fit together and then thought of the idea that all the continents of the world were once joined together into one big super-continent known as 'Pangaea'. He also found similar land forms, fossils and minerals on the coasts of Africa and South America. This proved his theory on continental drift.
Why are they moving?
Earthquakes are the Earth's natural means of releasing stress. The earth is made of around 8 major plates. These plates are part of the earth’s crust and are floating of top of an area of the earth known as the mantle. This is the driving mechanism for the plates.
Earthquakes are caused by Plate Tectonics. As the plates move they put forces on themselves and each other. When the force is large enough, the crust is forced to break. When the break occurs, the stress is released as energy which moves through the Earth in the form of waves, which we feel and call an earthquake.
The earth's crust consists of a number of sections or plates that float on the molten rock of the mantle. These plates move on convection currents caused by heat rising from the centre of the earth. The hot magma rises and spreads out on the surface, creating new crust. The crust spreads out forming a new plate until it meets another plate. One of the plates will be pushed down into the interior of the earth and reabsorbed into the mantle. The plates are the Earth's crust that floats on the molten rock in the centre of the Earth. Most of the inside of the Earth is so hot that the rock just simply melts away. The molten rock, which is also known as magma, bubbles up very slowly in great currents under the surface of the Earth.
The crust that floats on the magma moves with it. The Plates are just pieces of the crust. Just like a giant jigsaw puzzle. The part that makes it hard to understand is that it all moves extremely slowly. Just a few cm a year, roughly at the same rate your finger nails are growing.
Earthquakes are caused by Plate Tectonics. As the plates move they put forces on themselves and each other. When the force is large enough, the crust is forced to break. When the break occurs, the stress is released as energy which moves through the Earth in the form of waves, which we feel and call an earthquake.
The earth's crust consists of a number of sections or plates that float on the molten rock of the mantle. These plates move on convection currents caused by heat rising from the centre of the earth. The hot magma rises and spreads out on the surface, creating new crust. The crust spreads out forming a new plate until it meets another plate. One of the plates will be pushed down into the interior of the earth and reabsorbed into the mantle. The plates are the Earth's crust that floats on the molten rock in the centre of the Earth. Most of the inside of the Earth is so hot that the rock just simply melts away. The molten rock, which is also known as magma, bubbles up very slowly in great currents under the surface of the Earth.
The crust that floats on the magma moves with it. The Plates are just pieces of the crust. Just like a giant jigsaw puzzle. The part that makes it hard to understand is that it all moves extremely slowly. Just a few cm a year, roughly at the same rate your finger nails are growing.
How The Continents Move...
The different layers within the Earth are the Core, the Mantle, the Outer Core and the Inner Core. See page 171 of textbook.
Powered by forces originating in Earth’s radioactive, solid inner core, these tectonic plates move heavily about at many different speeds and in different directions above a layer of much hotter, softer, more malleable rock called the asthenosphere. Because of the high temperatures and immense pressures found there, the highest part of the asthenosphere is deformed and flows almost plastically just beneath the Earth’s surface. This characteristic of the asthenosphere to flow allows the plates, along with the continents to 'inch' along on their endless journeys around the surface of the earth.
Overall...
In conclusion, the current theory regarding how the Earth will change is plate tectonics. The tectonic plates that are found within the Earth's crust are moving which is resulting in the positioning of the continents on Earth to also move. Although the movement speed is ultra slow at 1 centimetre to 10 centimetre per year, the difference over 200 million years will definitely be noticeable.