Plate Tectonics
1. 2,000 strong earthquakes occur every year around the world.
2. Tectonics Theory states that the surface of the earth is not fixed and eternal, but is in constant, ever changing motion. Mountains rise and fall, oceans open and close, and life flourishes because of tectonic activity.
3. The tectonic forces originate deep within the planet.
4. Earths 3 main layers are a central core, a thick mantle, and a very thin outer crust.
2. Tectonics Theory states that the surface of the earth is not fixed and eternal, but is in constant, ever changing motion. Mountains rise and fall, oceans open and close, and life flourishes because of tectonic activity.
3. The tectonic forces originate deep within the planet.
4. Earths 3 main layers are a central core, a thick mantle, and a very thin outer crust.
5. Tectonic activity is concentrated in the upper 700 kilometers of the planet, in the uppermost mantle and the crust.
6. The Lithosphere is the outer mantle and the crust are fused together into a rigid, rock layer, about 100 kilometers thick.
6. The Lithosphere is the outer mantle and the crust are fused together into a rigid, rock layer, about 100 kilometers thick.
7. The asthenosphere is a solid but soft layer of the upper mantle. The asthenosphere is squishy-- it can deform and flow, though extremely slowly-- so that the heavy plates literally float on top of it. It is important to plate tectonics because this is when the plates begin to move.
8. Plates move slow-- averaging about the same speed that fingernails grow.
9. 3 types of plate boundaries are plates that can pull apart, they can collide, or they can slide past one another.
10. Divert Boundaries is when lava spews from long fissures and geysers spurt superheated water. Frequent earthquakes strike along the rift. Beneath the rift, magma--molten rock-- rises from the mantle. It oozes up into the gap and hardens into solid rock, form new crust on the torn edges of the plates. Magma from the mantle solidifies into basalt.
11. Oceanic Crust is made of basalt.
12. Convergent Boundaries is when two plates collide with one another. The impact buckles the edge of one or both plates up into a rugged mountain range, and sometimes bends the other down into a deep seafloor trench. A chain of volcanoes forms parallel to the boundary, to the mountain range, and to the trench.
13. Granite is a light colored, low - density rock that makes up the continents. It is found when magma from melting plates solidifies.
14. Transform Boundaries is when natural or man made structures that cross the boundary are offset--split into two pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. As the plates alternately jam and jump against each other, earthquakes rattle through a wide boundary zone.
9. 3 types of plate boundaries are plates that can pull apart, they can collide, or they can slide past one another.
10. Divert Boundaries is when lava spews from long fissures and geysers spurt superheated water. Frequent earthquakes strike along the rift. Beneath the rift, magma--molten rock-- rises from the mantle. It oozes up into the gap and hardens into solid rock, form new crust on the torn edges of the plates. Magma from the mantle solidifies into basalt.
11. Oceanic Crust is made of basalt.
12. Convergent Boundaries is when two plates collide with one another. The impact buckles the edge of one or both plates up into a rugged mountain range, and sometimes bends the other down into a deep seafloor trench. A chain of volcanoes forms parallel to the boundary, to the mountain range, and to the trench.
13. Granite is a light colored, low - density rock that makes up the continents. It is found when magma from melting plates solidifies.
14. Transform Boundaries is when natural or man made structures that cross the boundary are offset--split into two pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon. As the plates alternately jam and jump against each other, earthquakes rattle through a wide boundary zone.