Posted on 04/14/2010 8:27:59 PM PDT by cogitator
Tooling around Panoramio, I found the Creux-du-Van in Switzerland, near Lac de Neuchatel. My first thought when looking at this was: "I'll bet they lost a lot of sheep on this thing."
What's the Creux-du-Van?
From Magic Places of Switzerland: Creux-du-Van
And from Wikipedia: Creux-du-Van
It's a cirque. And an impressive one. You can find it with "Creux-du-Van, Switzerland" on Google Maps.
This is a good area for Swiss cheese, I believe.
Click for full size.
Click for full size.
Click for full size.
Click for full size.
** ping **
Next week I’ll post the best of the Icelandic eruption, which entered an interesting (and more damaging) Phase II today.
Can you say “jokulhlaup”? (I can’t.)
That’s one big @$$ pothole.
That looks like an impact crater.
Whatever it is, I’m sure it’s Bush’s fault.
The two embedded links didn’t activate (Wikipedia and Magic Places of Switzerland).
Here is was Wikipedia has:
“A cirque (French for “circus”) is an amphitheatre-like valley head, formed at the head of a valley glacier by erosion. The concave amphitheatre shape is open on the downhill side corresponding to the flatter area of the stage, while the cupped seating section is generally steep cliff-like slopes down which ice and glaciated debris combine and converge from the three or more higher sides. The floor of the cirque ends up bowl shaped as it is the complex convergence zone of combining ice flows from multiple directions and their accompanying rock burdens, hence experiences somewhat greater erosion forces, and is most often scooped out somewhat below the level of cirque’s low-side outlet (stage) and its down slope (backstage) valley. If the cirque is subject to seasonal melting, the floor of the cirque most often forms a tarn (small lake) behind the Moraine and glacial till damming the outlet.”
http://en.wikipedia.org/wiki/Cirque
Formation of cirque and resulting tarn
Put me on your ping list if you have one. Thanks for the pics.
Creux du Van (Magic Places of Switzerland)
Creux du Van (Wikipedia)
We have dry falls here in the eastern part of Washington state. They were caused by massive flooding at the end of the ice age when a prehistoric lake, Lake Missoula (in present day Montana) broke through an ice dam and water flowed across northeastern Washington, literally.
This happened repeatedly between 15,000 to 12,000 years ago.
Oh, I left off the part about how much this glacial caused formation looks like a dry falls, only the dry falls are much larger and there are quite a few in existence.
The Hills are Alive, with the Sound of Muuuuuuuuuaaaahhhh.
Wikipedia says this feature is caused by erosion from glacial meltwater, not carving by ice.
And their article says this:
"the hollow may become a large bowl shape in the side of the mountain, with the headwall being weathered by constant freezing and thawing, and as well as being eroded by plucking."
http://en.wikipedia.org/wiki/Cirque
___________________________
Also from Wiki:
"Glacial plucking exploits pre-existing fractures in the bedrock. This plays a key role in opening and creating new fractures but has only provided small segments of loose material. This is then followed by the entrainment of the loosened rock by the ice. During the process of entrainment, loose rock material is frozen onto the base of the glacier and incorporated into the glacial ice. It is significant when the bedrock is highly jointed, as this allows meltwater to penetrate. Plucking is also known as quarrying.
As the valley glacier moves down the valley there is friction with the rock floor. This causes the basal ice of the glacier to melt (which helps lubricate the movement of the glacier)and infiltrate joints in the bedrock where it then freezes. As the glacier moves on, the rock now bonded to the glacier, is plucked from the floor into the base of the glacier and carried with it."
Wikipedia has been known to be wrong but hey, I’d never heard of this Creux-du-Van before this thread was posted.
Wonder if there are the same kind of formations in our own glacier parks.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.