PLATE TECTONICS

Question 1

1. What evidence did Alfred Wagner use to support his theory of continental drift?

The continents look as if they could be glued together or make a perfect fit in a puzzle. Then he notice if you put the pieces together other things also fit. For example, the Appalachian Mts. of the eastern U.S. matched perfectly with those in Scotland.

2. Why do you think people didn't believe continental drift theory when Wagner first explained it?

Wegener could not come up with an acceptable way to explain how the continents moved. He didn't have a way to say it and sound logical.

3.Who were the two scientist that brought forth supporting evidence to Wagner's theroy, and what was their evidence?

Arthur Holmes & Harry Hess

4. What are the three different types of plate boundaries, describe each type?

Divergent boundaries - Areas where plates move away from each other, forming either mid- oceanic ridges or rift valleys.

Convergent boundaries - areas where plate move toward each other and collide.

Transform boundaries - When two plates grind past each other with only limited convergent or divergent activity.

5. Give an example of a location on Earth where each type of plate boundary is present.

Divergent Boundaries-East Africa rift in Kenya and Ethiopia, and the Rio Grande rift in New Mexico.

Convergent Boundaries - An example of this type of collision is found on the west coast of South America where the oceanic Nazca Plate is crashing into the continent of South America.

5. Transform Boundaries- . The slice of California to the west of the fault is slowly moving north relative to the rest of California. Since motion along the fault is sideways and not vertical, Los Angeles will not crack off and fall into the ocean as popularly thought, but it will simply creep towards San Francisco at about 6 centimeters per year.

6.WHAT ARE 3 DIFFERENT TYPES OF CONVERGENT PLATE BOUNDARIES

7. Give an example of a location on earth where each type of convergent plate boundaries occur.

The Himalayan mountain range.

8.Explain what plate tectonics and ocean trenches have in common.

Subduction zone where one plate goes under the other.

9.How old are the rocks of the east coast of North America relative to the rocks right along Mid-Atlantic ridge, why do you think this is the case?

This is becuase the rocks along the coast were formed from the same process that is producing the new rocks along the mid Atlantic ridge now, but were formed longer ago when the ridge was just forming.

10. WHAT IS A CONVECTION CURRENT OR CELL, DESCRIBE HOW IT WORKS

11. What are the two main sources of heat inside earth?
Frictional heating, caused by denser core material sinking to the center of the planet. Heat from the decay of radioactive elements.

12. What types of tectonic forces create mountains?
Movements of tectonic plates create volcanoes along the plate boundaries, which erupt and form mountains.

13. What are horsts and grabens, and where can they be found?
A HORST is an elongated block bounded by parallel (normal, reverse, lateral) faults in such a way that it stands (above, below) the blocks on both sides. A GRABEN is a narrow block moved (upward, downward) between two (normal, reverse, lateral) faults.

14.The mountains of the Great basin were formed by plate spreading in that part of the North American Continent. What happens is, as a plate spreads apart, fault blocks start to form. Two blocks on either side will rise while the one in the middle sinks. The rising blocks are called horsts, the the sinking blocks are called grabens.

15. What are two bad things that can happen as a result of plate tectonics, how did plate tectonics cause these events?
a. Earthquakes occur as a result of the sudden movement of one tectonic platerelative to another. As a result of friction, they are often held in one particular position until stress builds up sufficiently that there is sudden movement. Shock from this movement is conveyed through the surrounding rock resulting in an earthquake.
b. Volcanoes, themselves rarely cause much destruction & death. However, poisonous gases emitted from stratovolcanoes do result in deaths of people & of farm animals.

16. What are 3 good things that plate tectonics provide for humans and how do they provide them?
a. Fertile soils - the physical breakdown and chemical weathering of volcanic rocks have formed some of the most fertile soils on Earth.
b. Ore deposits - Rising magma does not always reach the surface to erupt; instead it may slowly cool and harden beneath the volcano to form a wide variety of crystalline rocks
c. Fossil fuels-Heat and pressure at depth transform the decomposed organic material into tiny pockets of gas and liquid petroleum, which then migrate through the pore spaces and larger openings in the surrounding rocks and collect in reservoirs, generally within 5 km of the Earth's surface.

SOURCES

• http://loki.stockton.edu/~hozikm/geol/Courses/The%20Earth/Content%20Web%20P...
• http://www.warrencountyschools.org/userfiles/1576/Classes/19431/PLATE%20TEC...
• http://www.warrencountyschools.org/userfiles/1576/Classes/19431/PLATE%20TEC...
• http://en.m.wikipedia.org/wiki/List_of_tectonic_plate_interactions
• http://www.cotf.edu/ete/modules/msese/earthsysflr/plates3.html (Scroll down and press next for the other two)

SOURCES 6 - 10

• http://www.ehow.com/list_7501192_three-types-convergent-boundaries.html
• http://pubs.usgs.gov/gip/dynamic/understanding.html
• http://pubs.usgs.gov/gip/dynamic/understanding.html
• http://pubs.usgs.gov/gip/dynamic/understanding.html
• http://www.ucmp.berkeley.edu/education/dynamic/session1/sess1_earthcurrents...

SOURCES 11 - 15

• http://www.scientificamerican.com/article/why-is-the-earths-core-so/
• http://en.m.wikipedia.org/wiki/Mountain_formation
• http://www.jsu.edu/dept/geography/mhill/phylabtwo/lab4/hg.html
• http://www.answers.com/Q/How_were_the_mountains_across_Nevada_and_Utah_form...
• http://pubs.usgs.gov/gip/dynamic/tectonics.html