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Earth Systems Unit 1.notebook
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What is Earth Science?
• Earth science is the branch of science dealing with the constitution of the earth and its atmosphere.
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The Branches of Earth Science
Major
• Astronomy (celestial objects, space, and the physical universe as a whole)
• Geology (earth's physical structure, history and processes)
• Oceanography (physical and biological properties of the sea)
• Meteorology (processes and phenomena the atmosphere / weather)
Minor
• Crystallography (structure and properties of crystals)
• Geomorphology (physical features of the surface of the earth and their relation to its geological structures)
• Hydrology (properties of the earth's water and its movement)
• Mineralogy (study of minerals)
• Paleontology (fossil animals and plants)
• Petrology (origin, structure and composition of rocks)
• Seismology (earthquakes and related phenomena)
• Stratigraphy (order and relative position of rock layers / strata)
• Volcanology (volcanoes)
• Sedimentology (modern sediments and process of deposition)
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How is Earth Science Different?
• Earth science has a global perspective, especially when it is studied using a “systems” approach.
• Earth science draws from all the other sciences including physics, chemistry, biology, meteorology, and astronomy.
• Earth science requires consideration of time. It deals with sequences of events, causes and effects and time in terms of millions or billions of years.
How Does Earth Science Relate to Other Sciences
• Biology: study of plants, animals and their interactions with the environment
• Chemistry: the atomic nature of rocks, minerals, and living organisms
• Physics: description of movement within systems, forces at work
• Astronomy: formation, composition, and movement of the planets
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The Big Bang Theory / Solar Nebula Hypothesis Explanation
• We live in an expanding universe, that originated from a singular energy/matter source that eventually led to the creation of our own solar system.
• In a very simple sense, the big bang occurred and left a single point that contained all matter, energy and forces which over time expanded and changed into the universe as we know it.
• As a theory, the Big Bang has been tested to the point where it is generally accepted. The Big Bang theory deals with the universe as a whole.
• The Nebula Hypothesis deals specifically with our solar system and is an extension of the Big Bang Theory.
Another Explanation
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• 5 billion years ago a nebula (cloud of dust & gas) began to contract & pull inward
••as it contracted, it began to rotate
••the rotation caused flattening & faster rotation
••the middle setted into a hot dense protosun
••the remaining material settled into rings and some compressed into protoplanets
••planets near the sun should be small and rocky
••planets further should be large and gaseous
••this theory explains the formation of the basic parts of planets only (geosphere formation)
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Formation of Earth• when Earth first formed, it was a homogeneous mixture of materials
• the interior of Earth began to melt due to:> heat from natural radioactive decay> heat and pressure from asteroid & meteor collisions
• the melting allowed material to flow & settle based on density
• this melting process may still be occurring today
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Layers of Earth
The Crust
• the outer layer (5 70 km thick)
• continental crust is mainly felsic (light coloured igneous rock)
• oceanic crust is mainly mafic (dark coloured igneous rock)
• the lithosphere is the crust & the upper part of the mantle (around 100 km)
The Mantle
• thick (2880 km) semisolid rock similar to peridotite (very dark igneous rock)•• the upper part is the asthenosphere•• this is a hot layer that moves plates due to convection currents
The Core
• the outer core (2240 km) is molten iron & nickel•• b
elieved to be liquid (swaves cannot pass through it)•• t
he inner core (1280 km) is believed to be solid iron & nickel•• e
xtremely high pressure & density
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The Core
• the outer core (2240 km) is molten iron & nickel
• believed to be liquid (swaves cannot pass through it)
• the inner core (1280 km) is believed to be solid iron & nickel
• extremely high pressure & density
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Compositional Viewpoint (what it's made of)
• crust• mantle• core
Mechanical Viewpoint (structure)
• lithosphere (brittle / solid)• asthenosphere (semisolid)• lower mantle (solid)• outer core (liquid)• inner core (solid)
increased pressure
density
temperature
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1) Draw and label Earth's layers 3) Which layer has the greatest pressure?
4) Which layer has the lowest temperatures?
5) How is Earth like an apple?
2) Which layers are considered liquid?
Quick Review
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4 main s
Four Main Systems
• Hydrosphere• Atmosphere• Geosphere• Biosphere
• a system is made up of interacting parts that make up a complex whole
• the four systems work together to operate Earth in a beneficial way
• similar to the human body, if one system becomes damaged all systems suffer
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How could each event impact each of the four spheres?
1) Forest fire
2) Flood3) Volcanic Eruption4) Hydroelectric Dam
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How have you interacted with the four spheres today?
Geosphere
AtmosphereBiosphere
Hydrosphere
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Details on SpheresHydrosphere• 71% of Earth's surface is covered in water• this includes glaciers, ponds, rivers, groundwater and oceans• 97% of the hydrosphere is ocean• water changes through the water cycle (dynamic)
Atmosphere• thin, when compared to Earth's thickness• a blanket of air around Earth providing oxygen (and other necessary gasses) and protection for UV radiation• location of weather• oxygen carbon dioxide cycle (dynamic)
Geosphere• thought of as rocks, but also contains minerals and innerEarth materials• the geosphere is forever changing due to plate tectonics and mantle convection (dynamic)
Biosphere• all living organisms and their interactions• nutrients travel through food chains and are recycled through decomposition (dynamic)
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Dynamic Earth
• Earth is in a continuous state of change
Examples?
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