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30 Cards in this Set
- Front
- Back
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The Earth's 4 sphere's
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Geosphere – the solid earth
Hydrosphere – the watery part of our planet Atmosphere – the gaseous layer above Biosphere – the living realm of organisms |
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Geosphere
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the solid earth
Planets accreted from dust into planetesimals Planetesimals clumped together to form planets Colliding pieces (and radioactivity) created heat, warming the young Earth to melting This ended (or Earth started) about 4.6 billion years ago |
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3 major layers of Earth’s Geosphere
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Dense metallic core
Outer core liquid, inner core solid, 6000°C Ni-Fe Less-dense rocky mantle Changes with depth, some parts solid, others weak and plastic-like, flowing slowly Even less dense surface crust Crustal material varies widely |
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lithosphere
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– the crust and upper part of mantle
Average 100km thick Broken up into tectonic plates Plates float atop the weaker material 7 major (and several minor) plates are in constant motion |
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Hydrosphere
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– all Earth’s water
Oceans Glaciers Ground water Streams and lakes Atmosphere |
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Atmosphere
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– the gas layer surrounding the solid Earth
Mixture of N, O, CO2, Ar, other gases 99% in 1st 30km Acts as filter & blanket, and as heat transport medium |
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Biosphere
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– zone of living things
Water, land, air all contain life Life is affected by the environment Life also alters the environment |
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Systems
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any assemblage or combination of interacting components that form a complex whole
i.e.: the human body, a bacterium, an ecosystem Each “sphere” is a system |
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Surface systems
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– mainly solar powered
Mass and energy both move Chemical reactions change materials |
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Internal systems
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radioactively powered
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Gradualism (aka: Uniformitarianism)
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Hutton – slow change across long times]
i.e.: plate motions |
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Catastrophism
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Whewell – rapid events in short times
Floods, earthquakes, meteorites |
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Threshold effect
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slow or no initial change to environmental change
When threshold point is passed, change becomes rapid |
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Feedback mechanism
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one change affects another system component, amplifying original effect
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Humans and Earth Systems
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6,700,000,000 humans today
20% live in wealthy nations 1,500,000,000 live in poverty live on <$1/day 14,000,000 infants die/yr |
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1. The Earth’s core is part of the __________.
a. geosphere b. atmosphere c. hydrosphere d. biosphere |
geosphere
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2. Oceans cover __________ percent of the Earth’s surface.
a. 0.7 b. 7 c. 17 d. 71 |
d. 71
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3. Oceans contain __________ percent of the Earth’s water.
a. 2.5 b. 15 c. 65 d. 97.5 |
d. 97.5
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4. Water frozen in glaciers is part of Earth’s __________.
a. geosphere b. atmosphere c. hydrosphere d. biosphere |
c. hydrosphere
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5. Earth’s core consists mostly of __________.
a. iron and nickel b. frozen water c. solid rock d. gas |
a. iron and nickel
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6. The rigid, outer part of Earth, including the crust and the uppermost mantle, is called the __________.
a. atmosphere b. geosphere c. lithosphere d. hydrosphere |
c. lithosphere
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7. Liquid freshwater amounts to about __________ percent of Earth’s total water.
a. 0.64 b. 6.4 c. 16.4 d. 60.4 |
a. .64
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8. The atmosphere consists mainly of __________.
a. nitrogen and argon b. nitrogen and oxygen c. oxygen and carbon dioxide d. carbon dioxide and argon |
b. nitrogen and oxygen
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9. A __________ is a combination of interacting components that form a complex whole.
a. feedback mechanism b. catastrophic event c. threshold effect d. system |
d. system
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11. Homo sapiens and our direct ancestors have been abundant on our planet for about __________ percent of Earth history.
a. 0.1 b. 1.0 c. 10 d. 50 |
a. 0.1 percent
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12. Geologists estimate that Earth formed __________ years ago.
a. 4.6 billion b. 46 million c. 4.6 million d. 46 billion |
a. 4.6 million
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13. __________ means that the geologic processes operating today also worked in the past.
a. Gradualism b. Uniformitarianism c. Catastrophism d. Density layering |
a. gradualism or uniformiatarianism
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14. The Earth’s population (in mid-2009) was about __________ people.
a. 2.3 billion b. 4.5 billion c. 6.7 billion d. 8.2 billion |
c. 6.7 million
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15. According to current trends in Earth’s population development, it is likely that pressure on Earth’s resources will __________.
a. increase b. decrease c. not change d. be insignificant |
a. increase
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10. Earth’s surface systems are ultimately powered by the __________.
a. Moon b. mantle convection c. Sun d. radioactive decay in the Earth’s interior |
c. the sun
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