ocean midterm

ocean midterm - Week 1 Earths Early Years How old is the...

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Week 1: Earth’s Early Years How old is the Universe? How old is the Earth? How do we know the age of the Earth? 14 billion years ago = Big Bang; earth ~ 4.6 bill years old density stratification Where do elements lighter than iron come from? Where do elements heavier than iron come from? What are the processes involved? What do I mean by nuclear stability? How does this relate to life on Earth? lighter elements are made by nuclear fusion in the cores of stars. The heavier elements are made in the supernova explosions that take place at the end of a large star's life cycle; Nuclear Fusion- The process in which light atoms such as those of hydrogen and deuterium combine and form heavier atoms, releasing a great amount of energy, that primarily manifests itself in the form of heat. After a star begins fusion it is said to be in a state of nuclear stability. It does not expand or shrink at that time. It burns its hydrogen fuel at a steady rate, converting hydrogen to atoms as What is meant by density stratification? How did the Earth become density stratified? How does this relate to the oceans? What are the densities of material in each zone of the Earth? Earth has more dense materials in the middle, Earth was homogenous at first, but became density stratified. Gravity pulled most of the iron and nickel inward to form the planet’s core, causing gravitational energy and heating earth even more. Lighter minerals, on the other hand, rose toward the surface, forming Earth’s crust. Oceans formed due to a constant cycle of rain and evaporation, which eventually lead to the cooling of the earth?s crust and the ability for an ocean to form. Minerals remain on earth?s crust after rain evaporates; Lower Mantle: 4.5 g/cm3, Upper Mantle: 3.3 g/cm3, Lithosphere: Rigid, Continental Crust:2.7 g/cm3, Oceanic Crust: 2.9 g/cm3, Ocean Water: 1 g/cm3. How were the atmosphere and ocean formed on Earth? Where did the material come from? What process was involved? The atmosphere was formed when the gasses that were trapped inside the forming planet burped to the surface to form a second atmosphere.Oceans formed due to a constant cycle of rain and evaporation thanks to the clouds, which eventually lead to the cooling of the earth?s crust and the ability for an ocean to form. Minerals remained on earth?s crust after rain evaporates; The material came from inside of the earth along with the suggestion that a barrage of icy comets or asteroids collided with earth adding to the accumulating mass of water. Process = Outgassing- The volcanic venting of volatile substances. What do we know about the origin and early evolution of life on Earth? Did it happen in the ocean? What is the likely long-term fate of the Earth and Sun?
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ocean midterm - Week 1 Earths Early Years How old is the...

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