11-1-09

This week’s test (test 2), I felt, was much more difficult than the first test.  The material in test one was much more basic and was easier to study for than this last test. 

This week in class we started focusing on whats called, orogenies.  An orageny is described as a collision between two major tectonic plates on earth.  Over earth’s years, it has experienced mass movement due to tectoninc plates being pushed or pulled by magma rising to the surface due to melting in the mantle.  The first major orogeny was the tocanic orogeny.  The second was the avolonia orogeny or the arcadian, which involved the african plate crashing into the north american plate.  This collision may have led to the formation of the Appalachain Mountains in western North Carolina and up the eastern seaboard.  The third and final orogeny was called the alleghenian orogeny, which involved North America colliding with Godwana to form pangea, which also helped form the Appalachains.  This occured about 300 or 350 million years ago.

We also learned that North Carolina has three distinctive geographic regions.  The first is the mountain region, which obviously means that it is mostly made up of mountainous terrain.  The second is the piedmont.  The piedmont region flattens out and is located in the center of NC.  This is the biggest region of the three.  The third and final region is the coastal plain.  This is located on the eastern side of NC, and is comprised of mostly sand.  The geographic features of the coastal plain include flat, sandy, and borders the Atlantic. 

 Sarychev Volcano eruption cloud

The above picture represents an orbital photograph taken at the international space station.  This is what the eruption of the Sarychev Volcano looks like from above.  This volcanoe is located just northwest of Japan.  This is said to be one of the most active volcanoes on that island chain. After the eruption on June 12, ash was said to be discovered over 2400 kilometers from the volcanoe itself.  It is also said in the article that planes had to be diverted from the surrounding area because the explosion of ash was so bad in the atmospher around it. If you look closely at the picture you can make a few observations.  First, the volcano was obviously explosive, which is a characteristic of a cinder cone volcano.  Another look shows that the explosiveness of the volcano created a void space in the clouds that the eruption went through.  Also, you can tell from the color of the eruption that it was a combination of ash and steam.  It looks as though the steam portion of the residue is an enormous bubble.  I think it is particularly neat that volcanoes in pictures like this one form the mushroom looking explosion effects, similar to atomic bombs.  I personally enjoy seeing photos such as this one because I am interested in the beauty that so called “natural disasters” such as this one cause.

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One Response to 11-1-09

  1. amelianavarro says:

    i agree that this midterm was more challenging than the first one. This post helped me understand the significance and meaning of orogenies.

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