Plate Tectonics and the Ocean Bottom

World
Today, our goal is to develop an understanding of the theory of plate tectonics and how moving plates create the ocean bottom.  
This Dynamic Earth is a web site put together by the USGS and we will be using it extensively.  Don't neglect the side bars at the bottom of each page.  Much of the information you want will be there.  As always you are encouraged to use your textbook, today chapter 2. 
Alfred Wegener
From the above web site click on "Historical Perspectives".  After reading this section, answer question #1 below.   (Image from: www.stchas.edu/faculty/ewilson/Photos/Plates)

Move on to the section "Developing A Theory".  After the death of Alfred Wegener, his theory (although initially dismissed) continues to be develop by the accumulation of new evidence.  All of the following individuals and technology contributed to an important aspect of Plate Tectonics called Sea Floor Spreading.  Once you have finished reading this section.  Answer question #2 below.             

Move on to "Understanding Plate Movements".   Read about the different types of plate boundaries (Divergent, Convergent, and Transform).  Go on to answer question #3 and #4 below.  

Go on to "Hot Spots" and answer question #5. 
Click on the following link: World seismicity map.   Examine the picture (you can click on it to make it larger) and answer question #6 and #7.
Go to: http://www.ncedc.org/anss/maps/cnss-depth.html.  Click on the four highlighted boxes and the information revealed about Earthquake depth and location and answer questions #8.
Finally go to: http://www.pacificislandtravel.com/nature_gallery/pacificislands.htm and read the scientific explanations for the formation of different ocean bottom features (abyssal plains, continental shelves, etc.)  Answer question #9 and #10.

Ocean Bottom Features

Questions to Research:

  1. Historical Perspectives: Briefly describe Alfred Wegener's theory and the evidence he used to support it.  Also identify what question Wegener failed to resolve.
  2. Developing A Theory: Explain the contributions of at least two scientists and two pieces of new technology that allowed for the development of a theory in plate tectonics known as "Sea Floor Spreading".
  3. Understanding Plate Movements: Draw pictures of the different types of plate boundaries (Divergent, Convergent, and Transform) with arrows to indicate movement.  Under each, identify the oceanic features ( undersea mountains, trenches, islands, etc.) they tend to form.   Finally, include an example of each that could be found on a map (i.e. The Great Rift Valley of Africa is a divergent plate boundary.)
  4. Examine the image below.  Based on what you have learned about sea floor spreading, explain what the different colors on this map mean.
  5. Map of Ocean BottomsHot Spots: Describe why there are volcanic islands (i.e. Hawaii) in the very middle of the Pacific Plate?
  6. World seismicity map: Explain how map's like these added some of the most significant evidence to the Theory of Plate Tectonics.
  7. Explain how the movement of oceanic plates (the Pacific Plate in particular) is related to the depths and locations of earthquakes in the pacific rim.
  8. Subduction Zones: Of these four "Subduction Zones" you are asked to examine (Japan, Alaska, Tonga, South America) which one is the oceanic plate being pushed down at the steepest angle.
  9. Ocean Bottom Features: Of all these ocean features, what does the majority of the ocean bottom look like?
  10. Guyotes and Sea Mounts: These are areas of incredible biological diversity.  They often see large gatherings of fish, sharks, and squid.  How are they formed?