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69 Cards in this Set
- Front
- Back
How is the earths crust like a ship? |
The crust floats on the mantle like a ship floats on water. The crusts vertical position, as well as the ships is determined by density |
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Why was the early bombardment of space debris important to differentiation? |
The kinetic energy of space debris colliding with earth was transformed into heat energy. The heat melted the earths rock so it was molten and could flow. If the rock was solid it couldn't have settled into such distinct layers. |
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What is the order of the spheres? |
Lithosphere, asthenosphere, lower mantle, outer core, inner core. |
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What part of the earth do S-waves not pass through? |
S-waves can't pass through liquid so they can't pass through the liquid outer core. |
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What is the Moho how was it discovered? |
The boundary between the earths mantle and crust detected my mohorovicic, who observed an increase of speed across it. |
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What evidence would lead someone with no scientific knowledge to suspect that the continents were once connected? |
The matching lines of south america and africa on a globe |
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How is the seafloor recycled? |
New lithosphere is created where magma wells up at a spreading center, and it is destroyed when it sinks back into the mantle at a subduction zone. |
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how does the theory of plate tectonics differ from the theory of continental drift? |
plate tectonics states that plates not just the continents move. Also because the theory includes seafloor spreading, it provides a way for continents to move, a mechanism. |
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Why does the asthenosphere flow? |
convection is the reason the asthenosphere flows. It is at the top of a convection cell that carried heat away from earths surface. |
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What role does gravity play in plate motion? |
Gravity pulls the dense edge of the older sphere into the asthenosphere. this pulls the res of the plate as well |
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asthenosphere |
one of the earths structural layers- a layer of weak warm rock the flows slowly over geologic time. |
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continental drift |
The hypothesis that the worlds continents move slowly over earths surface |
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convergent boundaries |
places where tectonic plates come together |
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Core |
Earths innermost layer, mostly iron, includes inner and outer core |
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crust |
earths surface layer, consisting of oceanic and continental crust |
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Differentiation |
The process by which the earth formed layers according to density. |
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divergent boundaries |
places where plates pull apart
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Earth Science |
study of history structure and natural processes of planet earth |
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Earthquake |
the shaking of ground that results when rock under the earths surface moves or breaks |
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Geology |
The earth science concerned with the composition and structure of earth |
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Inner Core |
A solid sphere of hot metal, mostly iron at the center of the earth |
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Lithosphere |
Earth's outermost structural layer, consisting of cool rigid rock |
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Lower Mantle |
The lowest portion of the Mantle a zone of strong rigid rock |
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Magma |
Molten rock in the earths Interior |
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Mantle |
Thick layer of dense, hot rock between earth's crust and core |
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Mid-Ocean ridge |
A global system of underwater mountains created by seafloor spreading |
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Ocean Trenches |
Long, Deep, Steep troughs in the seafloor where an oceanic plate sinks beneath an overlying plate |
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Outer Core |
A shell of hot liquid beneath the mantle and above the inner core |
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Plate Tectonics |
The theory that earth's lithosphere is divided into large plates that move slowly around the globe |
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Seafloor Spreading |
The process by which new lithosphere is created at mid-ocean ridges as older lithosphere moves away |
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Seismology |
The study of seismic waves, waves that travel through the earth as a result of an earthquake or other disturbance. |
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Subduction |
the sinking of oceanic lithosphere into the mantle. |
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Subduction Zone |
The region where an oceanic plate sinks into the asthenosphere at a convergent plate boundary |
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Tectonic Plates |
Separate pieces of lithosphere that move on top of the asthenosphere |
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Transform Boundaries |
Places where tectonic plates slide along beside each other as they move |
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The lithosphere includes the crust and top part of the |
Mantle |
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The layer of earth made up of soft rock that flows slowly over time is the |
asthenosphere |
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What type of plate boundary lies between two plates that are moving away from each other? |
Divergent |
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A long deep steep depression in the seafloor where subduction occurs is an |
Ocean Trench |
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Is the earth's inner core a solid, liquid, or gas. Why? |
a solid because the pressure keeps it from melting |
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Why is the outer core the source of the earths magnetic field? |
Moving liquid iron particles there form an electric current and an electric current always produces a magnetic field. |
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Why doesn't the heat in Earth's core melt the earth? |
Heat escapes slowly because rock is a poor conductor |
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Why is the inner core earths most dense region? |
The inner core is made mostly of iron dense material sank toward the earth when it was molten pressure packs atoms in the inner core tightly together |
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Fossils such as glossopteris and mesosaurus have been found in widely separate continents because |
The continents were once connected in a supercontinent called pangea |
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Plate Tectonics Explains |
How seafloor spreading and subduction account for the movement of tectonic plates Why the continents move Why plate boundaries are such active geologic regions |
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Chemical Rocks |
Sedimentary rocks formed from minerals precipitated out of solution |
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harry hess |
seafloor spreading |
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wergner |
Pangea |
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lehman |
proves earth is layered |
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mohorijivic |
crust and mantle |
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hutton |
father of modern geology |
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how do scientists study the earths layers?What role do seismic waves play? |
Scientists study the earth through seismic waves created by earthquakes |
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What layer creates the magnetic field how? |
The outer core creates the earths magnetic field because it is full of heated moving particles that are creating a magnetic field |
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How does the crust makeup differ from the core in respect to the elements found there? |
The crust has lighter elements like oxygen or hydrogen while the core has more dense elements like iron. |
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What are the two types of crust? where do they occur? Which is more common? Why is the continental crust thicker? |
Continental- makes you the landmass oceanic-underlies the ocean (most common) Continental crust thicker because it has roots that go down under the earth |
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Where do you find the youngest oceanic crust? |
near mid-ocean ridges where it is created |
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Describe the process of seafloor spreading? who discovered it? |
harry hess, new lithosphere is created at midocean ridges |
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how are earthquakes and volcanos related? How do we measure earthquakes? what scale is used? |
earthquakes and volcanos both occur at plate boundaries. The ricter scale is used to measure earthquakes. |
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What are the three different types of faults? |
divergent, convergent, transform |
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divergent |
plates moving away from each other ex: seafloor spreading |
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convergent |
plates moving toward each other. One plate ends up overtaking the other one. |
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transform |
plates sliding against each other the san adreas fault line |
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What are minerals? What are they composed of? |
material that has 5 characteristics naturaly occurring inorganic crystal structure solid specific chemical comp |
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what is the most common mineral on earth? |
quartz |
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how are minerals formed? how do we measure hardness? what scale is used? why is color not a good identifier of mineral indentification? |
crystalization, resistance to scratching, mohs scale, some minerals can exist in different colors |
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Describe the different types of minerals with regards to how they are formed? |
Cooling magma, Hydrothermal solutions, Evaporation, Pressure and temp change |
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What is the difference between intrusive and extrusive rock?What are their other names? What is stone mountain? Which ones are created from a volcano?
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intrusive, plutons, forms from magma underground Extrusive igneous or volcanic rock stone mountain intrusive |
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Describe the three types of rocks. How do they differ? How are each of them formed?which is the most common at earths surface? |
sedimentary igneous metamorphic
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Describe the two types of weathering that can occur to rocks? How do they differ? |
Clastic- Formed when bits and pieces of weatherd rocks to hold together
Chemical- when minerals percipitate out of a solution |