Plate Tetconics

PART ONE
Importance of:
1) Pangaea-- Some 225 million years ago all the world's land masses were joined together into one supercontinent, Pangaea, surrounded by a single universal sea, Panthalassa. Through the upheavals that we have since come to know as plate tectonics, the shifting of the Earth's crust tore the supercontinent asunder about the middle of the Mesozoic period (approximately 180 million years B.P.) and large bodies of land drifted across the surface of the Earth to ultimately become our present-day continents.(http://www.pangaea.org/continen.htm)

2) Sea Floor Spreading-- This helps explain continental drift in plate tetonics. Sea-floor spreading is the process in which the ocean floor is extended when two plates move apart. As the plates move apart, the rocks break and form a crack between the plates. Earthquakes occur along the plate boundary. Magma rises through the cracks and seeps out onto the ocean floor like a long, thin, undersea volcano.(http://library.thinkquest.org/17457/platetectonics/4.php)

3) Plate Boundaries-- Plate boundaries are found at the edge of the lithospheric plates and are of three types, convergent, divergent and conservative. Wide zones of deformation are usually characteristic of plate boundaries because of the interaction between two plates. The three boundaries are characterized by their distinct motions. the create tremors that help move plates.(http://scign.jpl.nasa.gov/learn/plate4.htm)

4) Ring of Fire-- In a 40,000 km horseshoe shape, it is associated with a nearly continuous series of oceanic trenches, volcanic arcs, and volcanic belts and/or plate movements. The Ring of Fire has 452 volcanoes and is home to over 75% of the world's active and dormant volcanoes.Ninety percent of the world's earthquakes and 80% of the world's largest earthquakes occur along the Ring of Fire.he Ring of Fire is a direct result and consequence of plate tectonics and the movement and collisions of crustal plates. (http://en.wikipedia.org/wiki/Pacific_Ring_of_Fire)

5) Mid Ocean Ridge-- A mid-ocean ridge or mid-oceanic ridge is an underwater mountainrift running along its axis, formed by plate tectonics. This type of oceanic ridge is characteristic of what is known as an oceanic spreading center. The uplifted sea floor results from convection currents which rise in the mantle as magma at a linear weakness in the oceanic crust, and emerge as lava, creating new crust upon cooling. A mid-ocean ridge demarcates the boundary between two tectonic plates, and consequently is termed a divergent plate boundary.(http://en.wikipedia.org/wiki/Mid-ocean_ridge)

6) A Shifting North and South Pole-- Over the past century the pole has moved 685 miles (1,100 kilometers) from Arctic Canada toward Siberia. The shift is likely a normal oscillation of the Earth's magnetic field, Stoner said, and not the beginning of a flip-flop of the north and south magnetic poles, a phenomenon that last occurred 780,000 years ago.Such reversals have taken place 400 times in the last 330 million years, according to magnetic clues sealed in rocks around the world. Each reversal takes a thousand years or more to complete.(http://news.nationalgeographic.com/news/2005/12/1215_051215_north_pole.html) range, typically having a valley known as a

PART 2
Volcanoes on the Moon and Mars-- It tells us that plate tectonics played a roll in shaping these masses.

PART 3
Motion Rates-- DUBO -- Latitude: -4.26 mm/yr. Longitude: -17.30 mm/yr.
HILO -- Latitude: 35.87 mm/yr. Longitude: -62.83 mm/yr.
KELY -- Latitude: 11.23 mm/yr. Longitude: -17.66 mm/yr.
HOFN -- Latitude: 14.87mm/yr. Longitude: 13.09 mm/yr.



PART 4
-The shift of mass and the massive release of energy very slightly altered the Earth's rotation. The exact amount is not yet known, but theoretical models suggest the earthquake shortened the length of a day by 2.68 microseconds, due to a decrease in the oblateness of the Earth.^[22] Because of its enormous energy release and shallow rupture depth, the earthquake generated remarkable seismic ground motions around the globe, particularly due to huge Rayleigh (surface) elastic waves that exceeded 1 cm in vertical amplitude everywhere on Earth. The earthquake was unusually large in geographical extent. An estimated 1,600 km (994 mi) of faultline slipped about 15 m (50 ft) along the subduction zone where the India Plate slides under the Burma Plate. The slip did not happen instantaneously but took place in two phases over a period of several minutes. Seismographic and acoustic data indicate that the first phase involved a rupture about 400 km (250 mi) long and 100 km (60 mi) wide, located 30 km (19 mi) beneath the sea bed—the longest rupture ever known to have been caused by an earthquake.(http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake)
-The Indian Ocean is kind of a heart or mitten shape.

PART5
-Alfred Wegener also came up with a theory to explain continental drift, although it was in error. His theory of continental drift proposed that centrifugal force moved the heavy continents toward the equator as the Earth spun. He thought that inertia, from centrifugal movement combined with tidal drag on the continents (caused by the gravitational pull of the sun and moon) would account for continental drift. Browsing the library at the University of Marburg, where he was teaching in 1911, Wegener was struck by the occurrence of identical fossils in geological strata that are now separated by oceans. The accepted explanations or theories at the time posited land bridges to explain the fossil anomalies; animals and plants could have migrated between fixed separate continents by crossing the land bridges. But Wegener was increasingly convinced that the continents themselves had shifted away from a primal single massive supercontinent, which drifted apart about 180 million years ago, to judge from the fossil evidence.^[2] Wegener used land features, fossils, and climate as evidence to support his hypothesis of continental drift. Examples of land features such as mountain ranges in Africa and South America lined up; also coal fields on Europe matched up with coal fields in North America. Wegener noticed that fossils from reptiles such as Mesosaurus and Lystrosaurus were found in places that are now separated by oceans. Since neither reptile could have swum great distances, Wegener inferred that these reptiles had once lived on a single landmass that split apart.This would help him be more believed. From 1912 he publicly advocated the theory of "continental drift", arguing that all the continents were once joined together in a single landmass and have drifted apart. In 1915, Wegener published the theory that there had once been a giant supercontinent, which, in later editions, he named "Pangaea" (meaning "All-Lands" or "All-Earth") and drew together evidence from various fields. Expanded editions during the 1920s presented the accumulating evidence. The last edition, just before his untimely death, revealed the significant observation that shallower oceans were geologically younger.