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Re: How Earth was Made-History Channel tonight

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avatar How Earth was Made-History Channel tonight
December 22, 2009 01:57PM
How the Earth was Made: New, HD, "Yosemite," The formation of Yosemite Valley in the Sierra Nevada mountain range in California is explored.

9 p.m. on History Channel tonight (6 Pacific if you can get the east coast feed). They'll look at why the granite comes off the valley's steep sides, among other things.

Link to History Channel
avatar Re: How Earth was Made-History Channel tonight
December 22, 2009 03:11PM
Quote
Vince
why the granite comes off the valley's steep sides

This explains it:

avatar Re: How Earth was Made-History Channel tonight
December 22, 2009 04:45PM
LOL something like that...the big G constant (ignore the rest)
avatar Re: How Earth was Made-History Channel tonight
December 22, 2009 05:35PM
Quote
Vince
LOL something like that...the big G constant (ignore the rest)

Constant? Rolling on floor laugh
avatar Re: How Earth was Made-History Channel tonight
December 22, 2009 05:00PM
Very excited about this episode! Geology is what brought me to the Sierra Nevada and I wrote a research paper on this very topic they are discussing....lets hope they are accuratesmiling smiley
avatar Re: How Earth was Made-History Channel tonight
December 22, 2009 08:07PM
I watched it and I thought it was well done. No mention of anthropogenic GW in it. It's au natural
avatar Re: How Earth was Made-History Channel tonight
December 23, 2009 11:27AM
I watched it and thought it was terrific. Most of it was familiar but I had not previously seen it explained why Yosemite granite is so much harder than many other locations. The give and go between Muir and the state geologist regarding why the Canyon bottom is squared off was also interesting. Of course, Muir's observation proved correct. Little things often jump out like the fact that the glacial moraine at the lower end of the canyon has numerous types of rocks in it such as one found from the Cathedral Peak area that would have required glacial transport. I thought this repoert was very well done.
avatar Re: How Earth was Made-History Channel tonight
December 23, 2009 01:58PM
So how did the river cut a deep valley through super-hard Yosemite granite in the first place?
avatar Re: How Earth was Made-History Channel tonight
December 23, 2009 02:19PM
The old Merced was pretty steep. Simular to the way it is on the way down 140. A little here, a little there, and you've got a V shaped valley.



Old Dude
avatar Re: How Earth was Made-History Channel tonight
December 23, 2009 02:24PM
Quote
mrcondron
The old Merced was pretty steep. Simular to the way it is on the way down 140. A little here, a little there, and you've got a V shaped valley.

Down 140 isn't the same rock.
avatar Re: How Earth was Made-History Channel tonight
December 23, 2009 04:51PM
The power of downhill water containing bits of sand and rock cuts quite a groove over millions of years. That made the V shaped valley. Subsequent glaciers hollowed it out into a U shape. "Lake Yosemite", formed by the last glacial moraine, filled in the V with silt to make it a box shaped valley. Then the state drained the lake to provide water for San Francisco.

grinning smiley



Edited 1 time(s). Last edit at 12/23/2009 04:53PM by tomdisco.
avatar Re: How Earth was Made-History Channel tonight
December 23, 2009 07:57PM
It was also because there was a massive amount of uplift due to a piece of the lower mantle that fell off thereby buoying up the spine of the Sierra....This much steeper grade allows gravity to work much more to the waters advantage with erosion...

I would agree this special really was pretty well done....It went much deeper into the Geology than any documentary I have watched thus far on Yosemite/Sierra Nevada...
avatar Re: How Earth was Made-History Channel tonight
November 18, 2010 08:20AM
Watched this show a couple of times now...
It's true you just don't see the glacial polish on the canyon walls like places
such as Grand Canyon Tuol, HH, or Cherry Creek Canyon to name a few.
However, this sure looks like it...





Chick-on is looking at you!
avatar Re: How Earth was Made-History Channel tonight
November 21, 2010 08:58AM
Oops... guess I should have said that that is Washington Column.



Chick-on is looking at you!
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