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Origin of the Earth. and Ocean. Age of the Universe. The universe is thought to be about 15 billion years old. The “Big Bang” theory states that it started off as a compact mass of matter, and is presently expanding at a very fast rate. Age of the Earth.
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Origin of the Earth and Ocean
Age of the Universe • The universe is thought to be about 15 billion years old. The “Big Bang” theory states that it started off as a compact mass of matter, and is presently expanding at a very fast rate.
Age of the Earth • Our planet was a giant, red hot, boiling sea of molten rock - a magma ocean, about 4.6 billion years ago. The heat had been generated by the repeated high speed collisions of much smaller bodies of space rocks that continually clumped together as they collided to form this planet. As the collisions tapered off the earth began to cool, forming a thin crust on its surface , and gravity pulled most of the iron and nickel inward to form a core. The lighter minerals floated to the surface to form the crust. (process lasted about 100 million years)
Origin of the Ocean • Oceans formed from water vapour trapped within the earth and released due to volcanic activity, about 4 billion years ago.
Formation of the Ocean • Hot vapours rose into the atmosphere, cooled, formed clouds and rained. (this lasted for about 10 million years)
Formation of the Ocean • Initially, vapour was boiling when it hit the Earth, and re-evaporated. Eventually the surface became cooler, rain stayed and formed primitive oceans in basins. Minerals began to dissolve into it resulting in salinity.
Origin of Life • About 3.5 billion years ago as clouds broke up, sunlight filtered through and enabled photosynthesis to take place.
First Interaction Between Life and Land • Oxygen was formed in the ocean before land. Tiny bacteria called stromatolites were among the first organisms to produce oxygen through photosynthesis.
Plate Tectonics • The Earths crust being created and destroyed.
Commotion Beneath the Ocean • The dynamic planet