Earth Science- Lecture 1
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- Nebular Hypothesis?
- Suggests that all the solar system formed from a big gigantic nebular cloud that consisted of 80% Hydrogen, 15% Helium, and 5% heavier elements.
- 5% of heavier elements?
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Mainly conisists of Silicon, Aluminum, Iron, and Calcium. These are the elements we see most rocks made of.
The rest of the elements are Nitrogen, Oxygen, and Carbon. - 5 Billion Years Ago?
- The nebular cloud (made up of gases and dust) began to contract and soon formed its own rotational movement.
- Nebula Contracted More...
- the rotational movement got faster and faster, and soon the cloud was pulled into a disk shape.
- Within the disk...
- There were several smaller contractions that eventually formed the nuclei from which our planets were formed.
- Biggest contraction?
- Formed at the center and created the protosun.
- Protosun?
- High temperatures eventually lowered and allowed all of the materials within the nebula that had a high melting point (like Iron and Nitrogen) solidify. Later they broke off into sand-sized particles.
- Calcium, Silicon, Aluminum, and Iron?
- Collided and formed large astroids that later created Mercury, Earth, Venus, and Mars.
- Mercury, Earth, Venus, and Mars?
- The inner or "terrestrial" planets. Due to their close proximity to the sun they are hotter, denser, smaller and have more earth-like features.
- Jovian Planets?
- The outer planets that were formed while the inner plants formed. They are made up of Nitrogen, Oxygen, Carbon, Carbon Dioxide, and Methane gases.
- Outter planets were far from the sun...
- Due to the frigid temperatures these planets consisted of ice-water, carbon dioxide, and methane gases.
- Big Bang Theory?
- Theory that our universe was one solid massive supernova ball. 20 billion years ago, a cataclysmic explosion broke the ball into pieces and sent them hurling through space. The pieces solidified and cooled there and formed the solar system we now observe.
- 20 Billion Years From Now...
- Our galaxies will slow and stop their forward flight and gravitational contractions will occur, causing the planets to combine and join as one mass. Thus birthing a new fire ball.
- In order for the galaxies to collide and coalesce...
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The universe has to have an average density of one atom for cubic every meter of space (35 cubic feet).
Estimates show that our density is far less than that. - 3 major parts of Earth from space?
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Hydrosphere
Solid Earth
Gaseous Atmosphere - These 3 parts of earth...
- Interact with one another. Shoreline meets the rocks, water, and air.
- Pictures show us that...
- AIR driven waves (water)hit the shoreline and one type of erosion takes place.
- Hydrosphere?
- Called the "blue plane." Oceans blanket 70% of the Earth and make up for 97% of Earth's water.
- Last 3% of Earth's water?
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Comes from things like lakes, ponds, creeks, streams, rain, etc.
Human consumption comes from this 3% and water has a sculpting effect on the environment. - Atmosphere?
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Radius of Earth is comparatively too thin with the earth at a 6400 km radius.
We breathe it and it protects our earth from radioactive sunrays and extreme heat. - Energy Exchange?
- Is constant between earth's surface and the atmosphere- and between the atmosphere and the space that creates the weather.
- Without the atmosphere...
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We'd have no erosion, no weathering, no life.
The earth would resemble the surface of the moon. - Solid Earth?
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Lies beneath the atmosphere and ocean. It has different composition:
Core
Mantle
Crust - Core?
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1216 km make up the dense inner core. Heavier elements make it denser- especially iron, magnesium, and nitrogen. The outer core is less dense and makes up 2270 km.
3486 total km. - Mantle?
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Less dense layer (center to surface= less dense). Made up of iron, magnesium and aluminum.
Upper mantle is rigid. Plate techtonics occur in the lower mantle. Moving capability is 10%- total of 2900 km. - Crust?
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Thinnest. Ligther/outer skin. The thinner portion.
Oceanic crust: the thinnest.
Continental crust: the thickest. - Lithosphere?
- Rigid outer layer (crust) and uppermost mantle.
- Biosphere?
- Consists of all life forms on Earth in the atmosphere and in hydrosphere. Since these spheres interact constantly, they change their physical environments.
- Earth Science includes:
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Geology
Oceanography
Meteorology
Astronomy