4th Period

By Sarah DraperPlate Tectonics

Plate TectonicsOverview

-Studying plate tectonics is basically studying the lithosphere, or portion of the Earth consisting the crust and part of the upper mantle.

-The lithosphere is divided into 12 huge plates which move around and interact with one another. When interacting they can create earthquakes, mountain ranges, volcanic eruptions, oceanic trenches, and much, much more.

12 Tectonic PlatesPlate: sections of the lithosphere that move around the Earth’s surface.

Boundary: where two plates meet.

History Of Pangaea!-Over 250 million years ago, during the Paleozioc Erathe Earth consisted of just one Continent now known as Pangaea.

Pangaea means ‘all

lands’.

Who Thought of Pangaea?

- In 1912, Alfred Wegener noticed how each continent fit together perfectly with one another.-People, including scientists, didn’t originally accept the idea of a Pangaea, a supercontinent, at first. It wasn’t until the 1960’s that people rethought what Wegener had noticed years ago.-During the time of Wegener introduced this, another theory was being more accepted, the contraction theory, which later scientists found out to be incorrect.

What led Wegener to his discoveries?

-Alfred Wegener was a geologist, meteorologist, and astronomer.-This came into play when he discovered how Earth’s 7 continents we have today used to be just one surrounded by a huge ocean, Panthalassa.-He knew the scientific method, and other good ways in finding, and testing theories.

Alfred Wegener put the idea of a supercontinent first in

1912.

Who assisted the idea of Pangaea?

-Arthur Holmes elaborated on Wegener’s findings. The repetitive

heating and cooling currents in the mantle can

lead to continents drifting. This idea relates

to Wegener’s original findings of the mantle undergoing thermal

convection.

Convergent Boundaries

-A convergent boundary is where two large tectonic plates come together. At these places

the two plates push against each other and one is forced upward while the other is forced

downward. When this happens on or near land huge mountain ranges can be formed and

volcanoes too, or in the ocean deep oceanic trenches may form.

What are the dangers of convergent boundaries?

Convergent boundaries can create huge mountains, volcanoes, and trenches.

Mountains: A natural elevation of land caused by

convergent boundary activity.

Volcano: a vent in the earth's crust through which

lava, steam, and ashes are ejected from the Earth.

Trench: a long, steep-sided, narrow

depression in the ocean floor.

Real World Examples-The Nazaca and South American convergent boundaries have pushed up limestone to create the huge Andes Mountain Range.

Divergent Boundaries-Divergent boundaries are plates that move away from each other. The rising current in the Earth pushes up on the lithosphere. The lateral flow causes the plates above to be pulled along with the direction of the flow below. The overlying plate stretches out and breaks apart.-These boundaries can cause earthquakes, volcanoes, and oceanic ridges.

Real World Examples

-When the Eurasian and North American spread apart, it created the Mid-Atlantic Ridge.

Transform Boundaries-A transform Boundary is where two plates slide against each other in a sideways motion. When transform boundaries slide against each other it can create massive amounts of energy causing even bigger earthquakes.

Earthquake: series of vibrations from two transform boundaries sliding against one another.

Real World Examples-The Alpine Fault in New Zealand is a huge transform fault line. It runs between the Pacific and Indo-Australian Plates.

What plate is Cincinnati on?

-Cincinnati, Ohio is located on the North American Plate. While this plate is the the biggest plate in the United States, some states are located on the Pacific or Juan de Fuca plates.

Is Cincinnati In Danger?

-Cincinnati is not immediately along any major fault line however the Madrid fault line is semi-close. This fault line mainly runs through Memphis, TN. However, we are in a slight bit of danger of earthquakes.-In the very distant future I predict that every fault line will have some sort of major activity. I also predict that continents will continue to move and reshape.

-Anywhere on the Madrid Fault Line is in some sort of earthquake danger. However, past records show that the danger is nothing too serious compared to many other places.

Landslides & Mudslides

Land Slide: downward falling, or sliding of a mass of soil or rock on or from a steep slope.

Mud Slide: the rapid downward movement of a large quantity of saturated earth

Bibliography!http://academic.emporia.edu/aberjame/histgeol/wegener/wegener.htm http://geology.com/pangea.htm http://allliance.la.edu/geomath/GeoMath3/lesson_files/VanArsdale/ELEVATE/PlateMotionsUSGS.pdf http://www.kidsgeo.com/geology-for-kids/0047-transform-boundaries.phphttp://www.physci.wsc.ma.edu/young/hgeol/geoinfo/timeline/pangaeacont/pangaeacont.htmlhttp://www.ucmp.berkeley.edu/geology/techist.html