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25 Cards in this Set
- Front
- Back
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crust |
the outer, solid layer of the earth. It is divided into continental and oceanic. Continental is less dense than oceanic. |
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mantle |
the middle semisolid layer of the earth. It is divided into upper (outer) and lower (inner). |
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core |
the innermost layer of the earth. The outer part of this is a liquid, and the inner part of this is a solid. |
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lithosphere |
the crust and the upper part of the mantle. Its importance is that we live on this layer. It is broken into pieces called plates. |
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asthenosphere |
it is in the upper part of the mantle. Its importance is that it is the location of the convection currents. It is a semisolid (like the consistency of silly putty or taffy or toothpaste or hot asphalt as they put it down to fill potholes). |
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continental crust |
The layer of the crust that we live on. It is LESS dense, warmer, and thicker than the other type of crust. |
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oceanic crust |
The layer of the crust that is under the oceans. It is MORE dense, colder, and thinner than the other type of crust. |
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trends in the Earth |
The DEEPER you go into the earth, the HIGHER the TEMPERATURE gets. The DEEPER you go into the earth, the HIGHER the DENSITY gets. The DEEPER you go into the earth, the HIGHER the PRESSURE gets. |
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convection currents |
the movement of the liquid rock in the asthenosphere that moves the tectonic plates (lithosphere). The heat from the core is the cause of the convection currents. The very hot material rises (because it is less dense), then cools (because it becomes more dense) because it is further away from the heat of the core, and then sinks. This process repeats over and over again. This process can happen in liquid or gas. It happens when you cook soup or boil water or heat/make pudding or in a lava lamp or in a refrigerator/freezer or in the heating/cooling of a room. |
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Pangaea |
scientists believe that about 300 million years ago (mya) all of the continents were together in a supercontinent |
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evidence in support of Pangaea |
1. shape of continents Ex: South American + Africa = fit like puzzle pieces 2. animal fossils found on continents separated by oceans 3. matching rock types + structures (mountain ranges) on continents separated by oceans 4. glacial deposits (in tropical regions) 5. tropical plant fossils found in polar regions |
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continental drift |
Alfred Wegner's theory about how the continents move (or "drift") on the surface of the Earth. |
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Alfred Wegner |
the scientist that came up with the theory of continental drift |
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seafloor spreading |
a divergent boundary where new crust is made as magma bubbles up and cools. Its discovery was the evidence needed for continental drift. |
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Mid Atlantic Ridge |
a divergent boundary at the bottom of the Atlantic Ocean where new crust is made. |
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Ring of Fire |
an area on the edges of the Pacific Ocean where MOST of the world's earthquakes and volcanoes occur |
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convergent boundary |
where plates move towards each other or ("collide") crust is recycled |
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convergent boundary: continent-continent |
when plates move towards each other or "collide") crust is folded and mountains are formed. Example: The Alps |
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convergent boundary: continent-ocean |
when plates move towards each other or "collide") more dense oceanic crust subducts or moves under the less dense continental crust. Deep-ocean trenches and coastal mountains are formed. Examples include the Cascade Mountains in the western US |
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convergent boundary: ocean-ocean |
when plates move towards each other or "collide") the older oceanic crust is more dense and subducts or moves under the less dense newer continental crust. Deep-ocean trenches and island arcs are formed. Examples include the Mariana Trench in the Pacific Ocean (deepest point in the ocean), and the island arcs include the Aleutian Islands in Alaska and the islands of Japan. |
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subduction |
when two plates move together, the more dense plate moves under the less dense plate. This is where crust gets recycled or melts and becomes part of the magma (liquid rock). |
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divergent boundary |
when two plates move apart where the plates split magma rises up and forms new crust |
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divergent boundary: ocean |
when two plates move apart; it forms mid-ocean ridges. An example of this landform is the Mid-Atlantic Ridge. |
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divergent boundary: land |
when two plates move apart; it forms rift valleys. An example of this landform is the Great Rift Valley in Africa. |
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transform boundary |
where plates slide past each other; it forms surface faults. Crust is not created nor destroyed. An example of a surface fault is the San Andreas Fault in California. |
