Lyell Glacier stagnant

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Tobia

Social climber
Denial
Feb 7, 2013 - 02:39pm PT
yep, in very slow motion.
Norwegian

Trad climber
Pollock Pines, California
Feb 7, 2013 - 04:25pm PT
dude that sucks,
the glacier aint gettin any action,

total dry spell, i can empathize,

i don't know,
just make the best of scenery for now,

and prop up yourself upon the
hope that big wet cold clouds
bring merry and unprotected
fornication that may well
advance your matrix.

may futures be yours.
here, you can have mine.
tuolumne_tradster

Trad climber
Leading Edge of North American Plate
Feb 7, 2013 - 05:46pm PT
for more info on the status of glaciers worldwide check out this website...

http://extremeicesurvey.org/

Also, documentary film "Chasing Ice"
http://www.youtube.com/watch?feature=player_embedded&v=eIZTMVNBjc4
Reeotch

Trad climber
4 Corners Area
Feb 7, 2013 - 06:24pm PT
That green stuff is probably olivine. Looks like some nice striations, too.
Sheets

Trad climber
Livermore, CA
Feb 7, 2013 - 08:53pm PT
Bummer,

Kind of mind blowing that the glaciers have shrunk so much in the last 100 years.
ionlyski

Trad climber
Kalispell, Montana
Feb 7, 2013 - 10:33pm PT
Am interested in an answer or some discussion on the question Scooter posed upthread. In short, is there a point considered the perfect amount of ice?

Arne
ionlyski

Trad climber
Kalispell, Montana
Feb 8, 2013 - 10:06am PT
In the world. Or in the USA. Or in Yosemite. Yes, it's coming or going. So, is there a point scientists agree on that is the optimum amount?

Sincere.

As Yosemite Valley was once filled with ice in the ,geologically recent past, what is the point of stasis that the measurement of how much ice should be on Earth vs. should not? Is there a year or epoch that scientist concur on as to when we had the perfect amount of ice?
BBA

climber
OF
Jun 9, 2013 - 11:33am PT
Maybe the optimum amount of ice is enough to prevent a lot of people from starving in various agricultural areas needing water (India comes to mind). It's a sociological question until the population bomb is defused.

The photo which follows is a panorama of Palisade Glacier in August of 1959. How's it doing these days? Any photos?

Vitaliy M.

Mountain climber
San Francisco
Jun 9, 2013 - 12:00pm PT

October


Mid August


Early February
sempervirens

climber
Jun 9, 2013 - 12:26pm PT
As Yosemite Valley was once filled with ice in the ,geologically recent past, what is the point of stasis that the measurement of how much ice should be on Earth vs. should not? Is there a year or epoch that scientist concur on as to when we had the perfect amount of ice?

That does sound like a climate change denier.

I can't answer but I'll assume those are valid questions. Has glaciology defined a point of stasis? Has there ever been a static amount of ice? It's true that the earth is dynamic, isn't that all the more reason to study what's going on? And a dynamic environment can still be affected by human activities (if that is what you are getting at).

A perfect amount of ice? Perhaps more useful would be, why did the glacier stop moving?, Can we predict other future conditions? what does this tell us about climate? There are many more questions we could ask.
Doug Tomczik

climber
Bishop
Jun 9, 2013 - 01:55pm PT
Bruce, this source should help to answer your questions.
http://www.antarcticglaciers.org/glacier-flow/
gstock

climber
Yosemite Valley
Topic Author's Reply - Jun 10, 2013 - 11:19am PT
That is a good link, Doug.

Bruce, you are correct that glaciers "creep" through internal deformation of ice. I often explain this as honey flowing down an tilted plate. In this situation the velocity at the honey/plate interface is zero, and increases upward to a maximum velocity at the surface; in essence, the closer you get to the surface, the more motion accumulates from below.

But glaciers, especially temperate ones, also move by basal sliding. In this situation, water at the bed of glacier reduces the basal friction and allows the glacier to slide along the ice/bedrock contact. The analogy here could be the same honey-on-a-tilted-plate scenario, but now the plate is coated with a thin film of oil that allows the whole blob of honey to slide across the plate. In reality the resisting stresses are much higher, so it's very unlikely that a glacier would ever just slip off the mountain!

In most cases total glacier movement is a combination of these two types of movement, with deformation occurring year-round and basal sliding contributing more during the summer melt season.

One of the conundrums of our studies of the Lyell and Maclure glaciers is that the Lyell has a greater surface area but has stagnated, whereas the smaller Maclure continues to move about 25 feet/year. We think that this has to do primarily with thickness - although the Lyell has a larger surface area, it must be very thin to exhibit no movement at all. If correct, this ice will probably melt away very fast in the coming years. I have already seen big changes in ice area in just seven years.

Conversely, the Maclure must still be thick enough to drive some deformation, and numerous crevasses allow meltwater to penetrate to the bed to cause sliding. Last year we placed ice screws into the base of the glacier (accessed by an ice cave at the glacier toe), and when we return this fall we'll measure that movement against the movement of stakes on the top of the glacier. In this way we should be able to parse deformation versus sliding.

Greg

Patrick Sawyer

climber
Originally California now Ireland
Aug 1, 2013 - 08:53am PT
So, as asked above, is Lyell still a glacier or just an ice field? Or has it yet to be determined which? I was only on Lyell once in the mid-1970s.
donini

Trad climber
Ouray, Colorado
Aug 1, 2013 - 10:18am PT
Y'all call that a glacier......Patagonia is having a wet, cold winter and there are big smiles on the glaciers. There is nothing sadder than a dying glacier.
Chiloe

Trad climber
Lee, NH
Aug 1, 2013 - 10:29am PT
Jim, do you have any personal observations from your years around Patagonian glaciers? I haven't been there but I've seen reports like this,

Patagonian Glaciers Melting in a Hurry
Ice fields in southern South America are rapidly losing volume and in most cases thinning at even the highest elevations, contributing to sea-level rise at "substantially higher" rates than observed from the 1970s through the 1990s, according to a study published Wednesday.


http://www.scientificamerican.com/article.cfm?id=patagonian-glaciers-melting-in-a-hurry
donini

Trad climber
Ouray, Colorado
Aug 1, 2013 - 10:36am PT
The Patagonia Ice Caps, North and South are the two largest ice caps outside of the polar regions.....1,500 and 5,500 sq. mi. respectively. The last few summers have been hotter and dryer than normal. This winter they are getting a reprieve....quite wet and cold.
I have noticed recession but the glaciers are so large it's hard to determine how much.
When I was on Mt. Kenya in 2005 I compared what I saw with earlier pictures and the rate of recession was astonishing.
SCseagoat

Trad climber
Santa Cruz
Aug 1, 2013 - 05:44pm PT
A phenomenal documentary if you haven't seen it already
ABOUT THE FILM Chasing Ice is the story of one man’s mission to change the tide of history by gathering undeniable evidence of climate change. Using time-lapse cameras, his videos compress years into seconds and capture ancient mountains of ice in motion as they disappear at a breathtaking rate. - See more at: http://www.chasingice.com/#sthash.sCHg1E2n.dpuf

http://www.chasingice.com/


Susan
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