Several billions of years ago, the Earth was hit by a meteor that helped kick start one of the most important events of the Earth’s history (All theory of course). Venus and Mars were not so lucky. Scientists think that the force helped kick-start the movement of the Earth’s plates that make up the outermost one hundred kilometers of the Earth’s crust, otherwise known as the theory of Plate Tectonics. This started the eventual earthquakes, volcanoes, oceans, mountains, etc. In other words it shaped the landscape of our planet, and from this landscape, life was born.
The theory of how it all started or “The Theory of Kick-Starting Plate Tectonics” started with the impact of an asteroid. Before the asteroid hit, the earth was in a state of cooling. The crust was “mushy” with a crusty surface and liquid mantle (magma). The asteroids impact caused solids from the crust to sink below and mixing with the different temperatures in the mantle’s magma. Magma shot up to the surface. Hot magma is rising and cool magma (surface crust) is sinking. This started a convection. As the hot magma rose, it cooled and sank. Then as it sank it reheated and rose again. The convection continues to this day, and the magma will probably keep sinking and rising as long as the earth has a hot, energy producing core. The earth is cooling, but at an extremely slow rate.
There are three different types of plate movement. Divergent is the movement of two plates away from each other. These can form the deep ocean trenches, but it can also form oceans between continents. A good example would be South America being split from Africa. It’s easy to see from maps that these continents were once next to each other. Convergent is the movement of plates into one another. These form the mountain ranges and volcanoes. A good example would be the great Himalayas. Transform is the horizontal movement of the plates against one another. These cause most of the earthquakes. A great example would be California.
The impact that the movement of our planet’s land masses has played an incredible roll in shaping life on earth. Continents have split apart, which has forced isolation of entire animal and plant ecosystems. This plays one of many major rolls in the forces of evolution. The ecosystem can be isolated for millions of years and eventually evolves on it’s own, and a great example would be Australia. Some of the animals there (ex. kangaroos) can be found no where else. However, the movement of the land masses can also bring continents together, thus mixing the plant and animal ecosystems.
Another effect of Plate Tectonics is the natural disasters. Volcanoes can shape not only the landscape but also the climate. Some scientists think that a volcano may have been the reason for the extinction of the dinosaurs. Earthquakes can destroy ecosystems in a matter of minutes. Tsunamis can wipe out an entire island that may have an isolated ecosystem on it that will never be seen again.
And so you may ask why is Plate Tectonics so important? Seen any life on Mars or Venus lately?