So first up, we have Dave's question!!!
The little lines on those hills were probably caused by one of two things.
The first possibility is that that area was once underneath a body of water, such as an ocean, and those lines were the features formed by the tides boring lines into the bedrock over a long period of time. If you drained the red sea, you would achieve a similar result. Do not try that at home, however!
The second possibility is that there was once a glacial dam in that spot, such as the one that was once in Missoula.
A glacial dam is a valley or bowl shaped indent in the earth with a hole in the side. During the ice ages, glaciers would have formed across these holes or ends of valleys, creating natural dams. Unfortunately, the dams would always collapse.
The problem was not from the thousands of tons of water pushing against it from the inside, but rather, an internal one.
Glacial dams are heavy. This means that they will not budge for anything unless they collapse. Well, the ice on top was ice, but that posed problems for the water in the glacier below (ice freezes top first). The ice on top would take up more space then it originaly would, as ice expands, and hence you would eventually have no room at the bottom for the water to expand. This would leave the water to try to escape the great pressure pushing down on it from the ice above.
This supercold water would flow through tiny cracks, and their kinetic energy would create little bursts of heat that would melt the cracks, expanding them. And you all know what happens when there are too many cracks in a dam...
BOOM!!!
The water on the other side would knock it over.
As this water was flowing out, it would pull at the earth, creating those lines.
(yay for long answer!)
Now George, how am I feeling this time?
I am feeling better now more then last time, as we are planning to go during a school break and into the SMALLEST school month of the year, so I will not be missing much. In Mexico, I would be going to a new school anyway, so I would probably not be going to see anybody anyway.
I think that this year, it actually might be better then last year... it is pretty much the school that melds my emotions at the moment anyway :)
So, thanks for reading guys!!! (And sorry if one answer was a LITTLE bit longer then the other, I had just learned recently about glacial lake missoula, and all the info was stuck in my head, it was easy to remember and easy to get out ^.^
Well, until next post, (which will be the next part of the story!)
-Xaviertrix
Thursday, November 12, 2009
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Thanks for the (long) answer, Francis. I don't know if it's right, but I will offer it to the kids along with the other answers I received. Others said the lines were made by water erosion, or by cows as the systematically grazed on the hillsides. I personally wonder if they are made by tractors tilling under the weeds every year. No one has been able to give a "for sure" answer yet.
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