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Scrooge
Famous Grouse



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Famous Grouse
PostMon May 21, 2007 3:06 pm 
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hijacked.gif       by me        hmmm.gif

We've got at least four threads running on related topics, right now, so I didn't want to confuse things with still another. However, this particular "disappearing glacier" is not in the Cascades, so after this post has been up for a couple of days, I'll respond to Peltoms' last question and get the thread back on track.        agree.gif

..............................

The June issue of National Geographic's cover story is "The BIG THAW .... Ice on the Run, Seas on the Rise", and their net site appears to have the entire article. Unfortunately, National Geographic does not post the pictures on the net that it uses in the magazine ........ because it was one of those photos that inspired this post.         suuure.gif

In the magazine, National Geographic has a very dramatic version of this 2005 photo of Grinnell Glacier in Glacier National Park.
In the magazine, National Geographic has a very dramatic version of this 2005 photo of Grinnell Glacier in Glacier National Park.
It looks more like this one, also taken in 2005 from about the same point.
It looks more like this one, also taken in 2005 from about the same point.
And still more like this one, which was taken from the other side. ....... Quite a nice glacial lake.
And still more like this one, which was taken from the other side. ....... Quite a nice glacial lake.

Larch and I went to Glacier National Park in 1964, and hiked up the trail to Grinnell Glacier. That's where we met our one and only grizzly bear, and somewhere I even have a 43 year old slide of him sitting on the snout of the glacier, where he went after changing his mind about continuing down the trail we were coming up.

There was no lake behind him. ...... When we were there, Grinnell was still a glacier, albeit a mostly stagnant one. It was my very first glacier, so after the bear clambered up over the top, I scrambled up after him (he was long gone). I walked out across the dirty ice and even climbed down into a small crevasse. ....... It was all a pretty big deal for an Eastern boy.

As I said, there was no lake. When we were there in 1964, it still looked pretty much like the 1957 version, below.

This collage from the net compares 2004 with 1957 ........ when there was no lake.
This collage from the net compares 2004 with 1957 ........ when there was no lake.

Not a very big or impressive glacier, but a real glacier, nonetheless. I've seen pictures of Grinnell from as far back as 1918, but the quality is not very good, so I'll spare you. Here's one more, though, that shows a sequence of views starting in 1938.

Melting of the Grinnell Glacier over a broader span of time.
Melting of the Grinnell Glacier over a broader span of time.

Compare that 1938 photo with the ones from 2005, above, and you'll get some feeling for what this "melting glaciers" topic is all about.

agree.gif   David

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Scrooge
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PostWed May 23, 2007 1:16 pm 
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All right, let's get this thread back on track.

peltoms wrote:
Thanks for the pictures which are enough evidence to demonstrate that Big Four at least was a glacier.  To create glacier ice you need a consistent 100 of snow-ioe thickness in our climate.  The pressure from more than 100 feet of ice inevitably generates glacier ice.  In Antarctica it takes more with the lack of melting and refreezing, the density of the snow is lower and remains low for longer as you descend into the glacier.     This ice mass is a reconstituted glacier just as you have beneath the Cascade pass trailhead, below Joburgs north face.  Such glaciers have concave basal slopes.  This is not conducive to much motion.  Scrooge's well documented crevasses still result from differential motion even if it is from some slumping and sagging, but it is not of just the surface this extends to depth which would not occur in a snowpatch or ice mass.  The November crevasse looks like it could be a bergshrund, but even these do not form in snow patches or ice masses typically. Some of the motion is due to frontal melting and the opening of the ice caves creating a greater surface slope.  In the last picture showing the confused stratigraphy this is typical, of an avalanche chute accumulation  on a glacier.  The thickness increases tremendously as you approach the center of the chute, causing the layer to thicken toward the center of Big Four.  Scrooge I would say there is no doubt that Big Four was a glacier up to 2002, by any definition.  By 2005 it is not clear if enough snow and ice exists.  What about 2007? We had two good avalanche years, which could have helped Big Four.

There was some rebuilding in the 2005-06 season, but it's only a start. Not a very good pictorial record from 2006, either, but I've picked up a couple.

Big Four Glacier, 09-28-2006 ..... alextrif,Flickr photo ....... Note the marked fracture lines.
Big Four Glacier, 09-28-2006 ..... alextrif,Flickr photo ....... Note the marked fracture lines.
Big Four Ice Cave in November, 2003, when the snow and ice was pretty much at the level it's been all this century.
Big Four Ice Cave in November, 2003, when the snow and ice was pretty much at the level it's been all this century.

At least one good sign is that all the snow that's showing in the 2006 photograph is new snow. All the old ice is still buried, even at the end of September. In fact, what is showing is not the "Ice Caves" at all, but just snow caves.

Big Four "snow caves", 09-10-2006 ....... Sir Hikes-alot,nwh,photo
Big Four "snow caves", 09-10-2006 ....... Sir Hikes-alot,nwh,photo
Interior of B4 "snow cave", 09-17-06 ...... adandan01.Flickr photo ........ Note that this is all new snow. There are no annual ice striations showing, at all.
Interior of B4 "snow cave", 09-17-06 ...... adandan01.Flickr photo ........ Note that this is all new snow. There are no annual ice striations showing, at all.

Compare those photos to the earlier pictures of the Ice Caves.

Scallops - in a side tunnel of the B4 Ice Caves, 2002
Scallops - in a side tunnel of the B4 Ice Caves, 2002
Ice Caves perspective - note the people and the small cave opening on the lower left.
Ice Caves perspective - note the people and the small cave opening on the lower left.

Water levels in the Stillaguamish are reliably low from July through September. I'll make a couple of trips up there during that time to record this year's situation.

Then, when the bridge is rebuilt, I have a new project in mind. Assuming that the Ice Caves survive, I'm very curious to see how, and to what extent, the caves are "filled in" with new snow and avalanche debris each year. ........ I'm assuming that any snow caves that survive the summer are destoyed the next winter, but that the caves in the ice persist from one year to the next.

Unfortunately, the classic Ice Caves won't last much longer, even if the glacier is rebuilt, but perhaps they'll give me time enough to complete my "study"         dizzy.gif

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weatherman
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climatologist
PostWed May 23, 2007 8:32 pm 
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In the past 10 years (1996-2006) there has been more snowmelt induced streamflow and it is coming later in the summer than the previous 10 years(1985-95) on the Skykomish River at Goldbar:

http://www.atmos.washington.edu/marka/skykomish.goldbar.1985_1996.gif

Perhaps this trend will help keep the Big Four Ice Caves alive and well for several more decades.
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Scrooge
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PostThu May 24, 2007 12:04 am 
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Weatherman said
Quote:
Perhaps this trend will help keep the Big Four Ice Caves alive and well for several more decades.

Unfortunately, one of the things that's producing that increased runoff is the melting of the pile of ice and snow that has been the Big Four Glacier.
The old ice in which the classic Ice Caves formed is almost entirely gone. Even if we're entering a period in which there will be substantial amounts of new snow persisting over several years, it looks like the rate of melting will be too great to allow any of it to stay around long enough to become glacial ice.

As long as we continue to have real winters here in the Northwest, we will have "snow caves" forming at the base of the Big Four cliffs. However, as summers warm and annual melting becomes more complete, the era of "Ice Caves" at 2000 feet is going to end.

edit - I realize that the melting Ice Caves don't really go to swell the Skykomish. Unfortunately, the records for the South Fork Stillaguamish are among the worst around (and the gaging station was discontinued entirely in 2005). As a result, I'm forced to accept Mark's decision to work with the best records available for a nearby area.

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marionthegoat
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That's a trail ??
PostMon Jun 04, 2007 9:23 pm 
Glacier Blues
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It's pretty clear to me that Glaciers in the Cascades have been generally receding in recent decades.  There's a lot more rock showing on Mt. Baker in September than I rememver seeing as a kid.

Glaciers are the result of several factors -- snow accumulation, concentration, temperature conditions, moisture content, humidity, solar exposure, slope, gravity  ... the resulting blob or river of ice is affected by changes in any of these.  It's my guess that the Pacific NW enjoys more glaciers than the rest of the continent by virtute of copious heavy, wet snowfall.  Places in Colorado may get as large a snowpack as the Olympics, and may have cooler mean temps, but they don't sport the ice we've got.

What I find rather amazing is that a short distance north of the border one can find ice at 1200' piled up under Robie Reid (ok, I'm not sure it's moving ...).  Drive north 100 miles or so and you get into ice fields that stretch on for 25-50 miles.  Is this dramatic difference due to latitude ?   Or because it's just so dang wet up there ?

1999 brought our mountains some of the heaviest snows in recorded history,  it took a couple years for the summer snowline to return to 'normal'.  Interestingly, the bulk of it fell in the spring months when it wasn't all that cold.  If we had this kind of La Nina weather aimed at us more often, I'd venture that the local glaciers would start tearing up the trees, warming trends notwithstanding.

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peltoms
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PostTue Jun 05, 2007 6:23 am 
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The lowered snowline to the north is a reflection mainly of cooler summer conditions.  Anyone who has lived in SE Alaska in the summer can attest that it is nothing like Seattle.  Winters are cooler at lower elevations of course with Juneau having weather most like Snoqualmie Pass.  It is not that much wetter in the winter.  In Colorado the actual snow depth is high but the snow water equivalent is much lower, thus when melt comes it lost much faster. And you are correct that wet weather can offset some warming.  However, this winter was quite wet and warm and we did not have great snowpack, 1999 was a cooler winter.
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Scrooge
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PostThu Jul 05, 2007 3:05 pm 
Big Four again
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Struggling with perspective .......

The winter of 2006-07 was a good one for the snow piles at the base of Big Four. However, trying to get a feel for how much snow there is, and how it compares with prior years, is quite a trick. There just aren't any convenient yardsticks to supply scale.

North face of 6135 foot Big Four. About 4000 feet visable in this picture.
North face of 6135 foot Big Four. About 4000 feet visable in this picture.
Main avalanche cone at the base of Big Four. About 400 feet high. The remnants of the Big Four Glacier are buried under this pile of last winter's snow.
Main avalanche cone at the base of Big Four. About 400 feet high. The remnants of the Big Four Glacier are buried under this pile of last winter's snow.
B4 avalanche cone on 07-03-07. The red line on the right is a "marker" to allow comparison with previous years.
B4 avalanche cone on 07-03-07. The red line on the right is a "marker" to allow comparison with previous years.
B4 avalanche cone 09-28-06. Marker line and height of 2007 cone indicated.
B4 avalanche cone 09-28-06. Marker line and height of 2007 cone indicated.
Big Four Glacier 09-04-05. Compare this pitiful pile of ice to the level of the avalanche cone in 2006 and 2007.
Big Four Glacier 09-04-05. Compare this pitiful pile of ice to the level of the avalanche cone in 2006 and 2007.
Oh yes, a little perspective from 09-04-05. Compare the people in the foreground to the arch of ice in the back ....... And then note that the arch is actually the side of that ice cave in the piddly pile of ice in the previous pic
Oh yes, a little perspective from 09-04-05. Compare the people in the foreground to the arch of ice in the back ....... And then note that the arch is actually the side of that ice cave in the piddly pile of ice in the previous pic

And then, if you can make the jump, try to relate the scale that the pic of the people provides with the size of one of the pics of the 2007 avalanche cone. ........ Climbing it took this old man quite awhile.

........ and with lighting.

I spent a couple of hours trying to record the size of the moat that's formed between the cliff and the ice, and trying to capture the feel of the amount of space in the voids that have formed underneath the upper edge of the ice ......... almost entirely without success.

I climbed up (almost) to the top of the main avalanche cone, hoping to get some pics right at the base of the falls. I was thwarted by the summit block, which turned out to be separated from the main body of the cone by an abyss, averaging 10 feet wide and 60 to 80 feet deep!

It's not a proper crevasse and I don't know whether it can properly be called a bergschrund, either. Perhaps the method of formation will provide a clue. ........ The waterfall coming down the cliff behind the avalanche cone carved a major moat all along the ice-rock boundary. It also cut deeper and deeper underneath the edge of the ice, till the unsupported weight became too much and a cube of ice roughly 100 feet on a side broke free from the main mass and fell back against the cliff, leaving the chasm.

Is it a bergschrund? Peltoms, if you'd care to comment?

B4 headwall pan. It's the block of ice at the top of the avalanche cone, about 100 feet wide, and separated from the bulk of the cone by a chasm 60 to 80 feet deep.
B4 headwall pan. It's the block of ice at the top of the avalanche cone, about 100 feet wide, and separated from the bulk of the cone by a chasm 60 to 80 feet deep.
Ice sculptures at the righthand end of the headwall. This pic covers about 20 verticle feet.
Ice sculptures at the righthand end of the headwall. This pic covers about 20 verticle feet.
Void matrix ....... The lengths some people will go to try capture the feel of an iceberg and a chasm.
Void matrix ....... The lengths some people will go to try capture the feel of an iceberg and a chasm.
Headwall ceiling pan ....... the overhangs that show on the left of the prior pic. They project out at least 10 feet from the main block of ice ........ and they're massive.
Headwall ceiling pan ....... the overhangs that show on the left of the prior pic. They project out at least 10 feet from the main block of ice ........ and they're massive.

Those are the pics from the top of the avalanche cone. Here are a few more from various sections of the moat. Mostly a sign of frustration.      mad.gif

Moat near the middle of the cliff. About 20 feet deep.
Moat near the middle of the cliff. About 20 feet deep.
Moat at the west end of the cliff. I'm standing on a ledge with the ferns. Everything behind them is 30 or 40 feet further down, and the lip at that point is undercut more than 20 feet!
Moat at the west end of the cliff. I'm standing on a ledge with the ferns. Everything behind them is 30 or 40 feet further down, and the lip at that point is undercut more than 20 feet!
Moat and arch verticle pan
Moat and arch verticle pan
Moat verticle pan
Moat verticle pan

Last, and maybe least, right now, is what everybody went to Big Four for, before.         rolleyes.gif          Only it's too soon. There are five major snow caves, the drain holes of those waterfalls coming down the cliffs. With light ....... and a certain degree of foolishness ....... you can probably make your way all the way back to the bases of the falls. But there wouldn't be much point in it. Although they're big enough to stand up in at the entrances, it would mostly just be cold, wet crouching and crawling. The spectacular arched caverns come later in the season.

B4 Avalanche cone and snow piles. The snow cave that drains what will become the Ice Caves is visible just left of center.
B4 Avalanche cone and snow piles. The snow cave that drains what will become the Ice Caves is visible just left of center.
Snow cave 1
Snow cave 1
Snow cave 2
Snow cave 2
Snow cave 3 pan
Snow cave 3 pan

Reminder: it's that time of year, folks. Please plan your glacier trips to take pics you can add to this thread.         agree.gif

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Dante
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PostThu Jul 05, 2007 3:24 pm 
Terraserver is a good resource
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Terraserver and other tools that let you toggle between USGS topos and more recent aerial or sattelite photos are a good resource.  See, e.g., Hinman Glacier LINK (1975 Topo, 1998 Photo).
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Tom
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PostSun Jul 15, 2007 5:56 pm 
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Here's a couple shots of Icy (first shot from UW digital archives, second shot borrowed from here):

Icy from Ruth (undated)
Icy from Ruth (undated)
Icy from Ruth (July 2007)
Icy from Ruth (July 2007)
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PostMon Jul 16, 2007 8:26 pm 
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From India.

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tofu on toast hiker
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Santiago!
PostSat Jul 21, 2007 6:58 pm 
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After catching the tail end of TrailsFest 2007, by which time the crowds were slowly receding, I went to Scott's Dairy Freeze.  I am happy to report that the Glaciers which they serve there are the same size as the have always been, and quite tasty as well, and they don't put a very deep crevasse in your wallet.  I had a lime Glacier.  Cool, slushy, yum!!!

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peltoms
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PostSun Jul 22, 2007 4:19 am 
big four abyss
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A bergshrund or a crevasse form as you know when the glacier accelerates downslope.  In the case of Big Four i wonder if the waterfall and moat formation cause the upper portion of the snow slope to sag down a bit opening a bergshrund of sorts separating the stationary snowfield from the sagging upper margin.  If this is the case there should be a good slope change at this point.  The slope change would not develop otherwise, as avalanches would smooth the slope.  So is there a slope change at the abyss?
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Scrooge
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PostSun Jul 22, 2007 9:54 am 
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peltoms wrote:
Is there a slope change at the abyss?

Ya. But I'm not sure it's the slope change you'd expect. ....... As I described, above, I do believe that the "crack" forms when the upper block is undercut and sags ..... back or down or something. My guess is that the block actually rotates as it sags, with the ends of the block being pivot points. The result is that the upper block forms kind of a topknot at the head of the avalanche cone, with the upper face of the block being a wall.

Big Four's 400 foot avalanche cone, 07-03-07
Big Four's 400 foot avalanche cone, 07-03-07
Avalanche cone2.2, showing the "topknot"
Avalanche cone2.2, showing the "topknot"
Avalanche cone from about halfway up. The change in slope is clear.
Avalanche cone from about halfway up. The change in slope is clear.
The topknot from 50 or 60 feet below the crack.
The topknot from 50 or 60 feet below the crack.
Best view of the wall that forms the upper face of the bergschrund.
Best view of the wall that forms the upper face of the bergschrund.
B4 headwall pan
B4 headwall pan

I guess one thing that makes this difficult to call is that all of the activity takes place in this year's snow and ice. It's not a matter of avalanches piling up on a base of glacial ice. The whole thing is an avalanche cone. The only remnant of glacial ice is more than 300 feet below.

The irregularity of the topknot suggests that there may have been a little bit of avalanche deposit on the top block, after the cone was basically stabilized and the undercutting begun. However, the amount of additional snow is comparatively trivial. The irregularity might also be due to the topknot being a group of broken chunks of ice, rather than a single block, but the lower face of the topknot is clearly the exposure of a single block.

Right-hand end of the Big Four ?bergschrund?
Right-hand end of the Big Four ?bergschrund?
Left-hand end of the Big Four ?bergschrund?
Left-hand end of the Big Four ?bergschrund?

As I said in the original post, whether it's a bergschrund, a crevasse, or just a crack in the snow, I found it essentially impossible to photograph. It is a huge chasm, in places 60 to 80 feet deep, and severely undercut on the lower side. At the right-hand end there appears to be an icy chockstone connecting the upper and lower blocks. At the left-hand end, there's just space. Crawling up far enough to look down into it was a little tense.         eek.gif

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Scrooge
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PostTue Aug 21, 2007 2:15 pm 
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Peltoms, this is the best I can do on the avalanche cone comparison.

Big Four avalanche cone, 07-03-07
Big Four avalanche cone, 07-03-07
Big Four avalanche cone, 08-14-07
Big Four avalanche cone, 08-14-07

When it's sunny, the changes in lighting from day to day and hour to hour play hob with trying to get similar photographs. These pics were taken from pretty close to the same spot, and I've tweaked and edited them to try display them at the same scale ........ but they're still not very good.     frown.gif

I've had much better luck getting comparative pictures of the details.

Snow bridge, 07-25-07
Snow bridge, 07-25-07
Former snow bridge, 08-14-07
Former snow bridge, 08-14-07

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peltoms
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PostFri Aug 24, 2007 5:28 am 
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Scrooge they look pretty good.  My point is make sure you are in the exact same spot, pick a unique rock etc, then use the same wide angle setting and you will have a perfect overlay potential.  I will try this with the two pics of the main fan.  Since the loss is all from melting, if the volume lost can be determined each year from such pictures that is a valuable piece of information.  Hence, you must return in one months time for an end of the summer picture.
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