Plate Tectonics

1. Plate Tectonics Sidney Swindell C1

2. Inner Core • Is a ball of hot, solid metals • Enormous amounts of pressure in the center of the earth • one of the two cores • This squeezes the atoms of the metal so closely together that the core the core remains solid • This core is in the center of the earth.

3. Outer core • The outer core of the Earth is a liquid layer about 2,266 kilometers thick composed of iron and nickel which lies above the Earth's solid inner core and below its mantle. • The temperature of the outer core ranges from 4400 °C in the outer regions to 6100 °C near the inner core. • Because of its high temperature, modeling work has shown that the outer core is a low viscosity fluid (about ten times the viscosity of liquid metals at the surface) that convects turbulently. • [1]Eddy currents in the nickel iron fluid of the outer core are believed to influence the Earth's magnetic field. • The outer layer is mostly liquid.

4. Mantle • The layer of the earth between earth’s outer core and crust • The mantle is a part of a terrestrial planet or other rocky body large enough to have chemically divided into layers. The mantle is a highly viscous layer between the crust and the outer core. Earth's mantle is a rocky shell about 2,900 km (1,800 mi) thick[1] that constitutes about 84% of Earth's volume.[2] It is predominantly solid and encloses the iron-rich hot core, which occupies about 15% of Earth's volume.[2][3] Past episodes of differentiation by density. The interior of the Earth, similar to the other terrestrial planets, is melting and volcanism at the shallower levels of the mantle have produced a thin crust of crystallized melt products near the surface, upon which we live.

5. Crust • The thin layer of rock above earth’s surface • All life in the universe that we know of, occurs there. • The crust is the coldest layer of all the layers of Earth. • The crust makes up less than 1% of the Earth's mass.

6. Lithosphere • The lithosphere is made up of the crust and uppermost brittle mantle. • The layer of earth made up of the crust and the ridged rock of the upper mantle • The lithosphere is the solid, rocky layer covering the entire surface of the planet, composed of the crust and the hard uppermost mantle, • and reacts • to stresses as a brittle solid. • The lithosphere ranges in thickness from 50 - 200 kmA and is fragmented into tectonic plates with boundaries where plates collide, diverge, or grind past each other. Read more: http://wiki.answers.com/Q/What_is_the_lithosphere#ixzz1l2vCXUiG

7. Asthenosphere • The layer of the earth’s upper mantle directly under the lithosphere MARY GEORGE KING IS AWESOME!!!!!! I LUV U!!! Sidneyyyyyyyyy SWINDELLLLL@!!!!! p(:p 

8. Tectonic Plate • One of the large moving pieces into which earths lithosphere is broken and which commonly carry both oceanic and continental crust • There are 14 • They are apart of the lithosphere • They cause earthquakes

9. Continental Drift • The hypothesis that earth’s continents move on earth’s surface • In 1915, the German geologist and meteorologist Alfred Wegener first proposed the theory of continental drift, which states that parts of the Earth's crust slowly drift atop a liquid core. • The fossil record supports and gives credence to the theories of continental drift and plate tectonics. • Wegener hypothesized that there was a gigantic supercontinent 200 million years ago, which he named Pangaea, meaning "All-earth".

10. Pangaea • A hypothetical super continent that once included all of the landmass • The Pangaea theory is one that states that all present continents were once together and collectively known as a 'supercontinent' called a Pangaea. • The word 'Pangaea' means 'all lands' in Greek, accurately defining the way the continents were 200 millions years ago before it split up. • These split-up pieces drifted slowly apart and became the way they are today.

11. Convection Currents • A circulation pattern in which material is heated and rises in one area, then cools and sinks in another area • The mantle is made of much denser, thicker material, because of this the plates "float" on it like oil floats on water. • Many geologists believe that the mantle "flows" because of convection currents. Convection currents are caused by the very hot material at the deepest part of the mantle rising, then cooling, sinking again and then heating, rising and repeating the cycle over and over. • The next time you heat anything like soup or pudding in a pan you can watch the convection currents move in the liquid. When the convection currents flow in the mantle they also move the crust. The crust gets a free ride with these currents • . A conveyor belt in a factory moves boxess like the convection currents in the mantle moves the plates of the Earth.

12. Divergent Boundary • A boundary along which two tectonic plates move apart • A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth's surface between the two plates • . The middle of the Red Sea and the mid-ocean ridge (running the length of the Atlantic Ocean) are divergent plate boundaries. • Also called passive margin, spreading zone

13. Convergent Boundary • A boundary along which two tectonic plates push together • A tectonic boundary where two plates are moving toward each other. • If the two plates are of equal density, they usually push up against each other, forming a mountain chain. If they are of unequal density, one plate usually sinks beneath the other in a subduction zone. • The western coast of South America and the Himalayan Mountains are convergent plate boundaries. Also called active margin, collision zone

14. Transform Boundary • A boundary along which tow tectonic plates scrape past each other • n plate tectonics, a transform boundary (also known as transform fault boundary, transform plate boundary, transform plate margin, strike-slip boundary, sliding boundary, or conservative plate boundary) is said to occur when tectonic plates slide and grind against each other along a transform fault. The relative motion of such plates is horizontal in either sinistral or dextral direction. Many transform boundaries are locked in tension before suddenly releasing, and causing earthquakes. Most transform boundaries are found on the ocean floor, where they often offset active spreading ridges to form a zigzag plate boundary. However, the most famous transform boundaries are found on land. • The most well known transform boundary in the world is the San Andreas fault. The scientists predict that in about ten million years, Los Angeles and San Francisco will be side by side.[1]

15. Magnetic Reversal • A switch in the direction of Earths magnetic field so that the magnetic north pole becomes the magnetic south pole • A geomagnetic reversal is a change in the orientation of Earth's magnetic field such that the positions of magnetic north and magnetic south become interchanged. • These events often involve an extended decline in field strength followed by a rapid recovery after the new orientation has been established. • These events occur on a scale of tens of thousands of years or longer, with the latest one (the Brunhes–Matuyama reversal) occurring 780,000 years ago

16. Hot Spot • An area where a column of hot material rises from deep within a planet’s mantle • In geology, a hotspot or hot spot is a portion of the Earth's surface that may be far from tectonic plate boundaries and that experiences volcanism due to a rising mantle plume or some other cause.[1]

17. Subduction • The process which an oceanic tectonic plate sinks under another plate • In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. • A subduction zone is an area on Earth where two tectonic plates move towards one another and subduction occurs. • Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately 2 to 8 centimeters per year (about the rate a fingernail grows).[1]