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christensent
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Joined: 05 Nov 2011
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Are the glaciers at Lake Serene actually solid glacial ice? Or are they just snow that built up during the last few heavy snow years?
 IMG_20141019_140408
Learning mountaineering: 10% technical knowledge, 90% learning how to eat
Learning mountaineering: 10% technical knowledge, 90% learning how to eat
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Randito
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Randito
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 Mon Oct 20, 2014 9:05 pm |
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Technically speaking -- those are permanent snow fields -- not glaciers. A glacier has enough thickness that the snow is compressed into ice and flows downhill.
The lowest elevation glacier in the lower 48 is the Carbon Glacier on Mt Rainier.
FWIW: The Big Four Ice Caves are bit lower than Lake Serene
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touron
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touron
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Mon Oct 20, 2014 9:05 pm |
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Don't forget the Little Si Glacier.
Touron is a nougat of Arabic origin made with almonds and honey or sugar, without which it would just not be Christmas in Spain.
Touron is a nougat of Arabic origin made with almonds and honey or sugar, without which it would just not be Christmas in Spain.
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Conrad
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Conrad
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Mon Oct 20, 2014 9:19 pm |
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| Jeff wrote: | | (maybe all 50?) |
Not all 50. I'm sure Alaska has glaciers that calve right into the ocean.
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gb
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gb
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Mon Oct 20, 2014 9:54 pm |
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| RandyHiker wrote: | | Technically speaking -- those are permanent snow fields -- not glaciers. A glacier has enough thickness that the snow is compressed into ice and flows downhill. |
The lowest permanent snowfields are likely:
1) The Big Four Ice Caves 1938'+
2) Lake Serene 2521'
3) Who knows, there may be a few low icefields in the North Cascades (Flat Creek, Luna Creek, McMillan Creek, Crystal Creek (Mt. Shuksan), Sulphide Creek, north side of Mineral Mountain all show permanent snow on old maps at very low elevations.
I just took a quick tour on Hillmaps.
The lowest glaciers (exact elevations aren't possible as all are retreating):
1) The small glacier at the foot of the Johannesburg Ice Couloir perhaps 3400' (it has cracks and a moraine)
2) Carbon Glacier 7-1/2' quad shows it at 3520' but likely retreated
3) Vesper Glacier (Copper Lake) Map shows 3620' but likely 300' higher)
4) Small glacier at Shuksan Lake 3811' (below Sulfide and Crystal Glaciers)
5) Blue Glacier, Mt. Olympus ca 3900'
6) Small glacier at the foot of Luna cirque ca. 3900' w/moraine but has likely retreated
7) Lower Price Glacier 3911'?
8) McCallister Glacier (map shows 3950' but has likely retreated)
9) Coleman Glacier (was as low as 3950')
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zhenya
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zhenya
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Mon Oct 20, 2014 10:12 pm |
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| gb wrote: | | The lowest glaciers (exact elevations aren't possible as all are retreating):
1) The small glacier at the foot of the Johannesburg Ice Couloir perhaps 3400' (it has cracks and a moraine) |
Aha...I was wondering about that thing.
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Ringangleclaw
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| gb wrote: | | The lowest glaciers (exact elevations aren't possible as all are retreating):
1) The small glacier at the foot of the Johannesburg Ice Couloir perhaps 3400' (it has cracks and a moraine) |
Don't mistake protalus ramparts and numerous 'schrunds as proof that a snow body is a glacier.
I would argue that the snowfields at Lake Serene, J-Berg and Big Four are not glaciers. They are below the firn line and receive their accumulation primarily as debri catchment. I would posit that a glacier should have now or in the recent past accumulated their mass above the firn line and that this mass should be contiguous.
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Randito
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Randito
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Tue Oct 21, 2014 11:25 am |
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FWIW: The current snout of the Carbon is at 3760, The Coleman at 4680.
The snow field at the bottom of J'Burg is interesting -- the moraine show evidence of movement at some point in the past -- However at the current time it appears to be a static snowfield.
I think the key difference between a permanent snowfield and a glacier is one of thickness and movement. A glacier is thick enough to compress the bottom layers into ice and then flow down the slope.
In the current era of retreating ice I think there are a number of glaciers that are shrinking enough that the movement is slowed or stopped and the formation of new ice greatly reduced or ended.
One example is the Paradise Glacier -- back in the '50s and '60s there was still a fair amount ice below the cliff band at 7200ft -- and enough ice was present to form the famous Paradise Glacier Ice Caves -- Nowadays there is still persistent snow below the cliff band down to about 6400-- but it is now no longer thick enough to move and the caves are no more.
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gb
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gb
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Tue Oct 21, 2014 11:28 am |
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| Ringangleclaw wrote: | | I would argue that the snowfields at Lake Serene, J-Berg and Big Four are not glaciers. They are below the firn line and receive their accumulation primarily as debri catchment. I would posit that a glacier should have now or in the recent past accumulated their mass above the firn line and that this mass should be contiguous. |
Argue away. But explain the moraine below the glacier.
It doesn't matter what the source of a glacier is. For instance, I am sure the Glacier below Vesper (which is likely pretty stagnant now but has moved some very big boulders in the past) is only there because deep snowpack accumulates on the rather extensive 45 degree slab, and avalanches off primarily in late June to mid-July. The existence of the slab drastically increases the area of the accumulation zone for that glacier and moves it's catchment area up to a more favorable elevation.
I think once a glacier, always a glacier until it's gone. Peltoms still refers to the Iceworm Glacier (Hyas Creek) and the Anderson Glacier as glaciers although movement hasn't been present for some time.
In Glacier National Park virtually none of the glaciers are still moving. The Grinnell Glacier certainly isn't,
I doubt even the good sized Sperry Glacier has much movement.
In the Wind Rivers the Grasshopper Glacier looks dead,
in the Sierra I know the Palisade Glacier
and Lyell Glacier aren't showing any advance even on a seasonal basis. No annual moraines.
Yet these are amongst the biggest glaciers in their respective ranges.
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Ringangleclaw
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| RandyHiker wrote: | | The snow field at the bottom of J'Burg is interesting -- the moraine show evidence of movement at some point in the past -- However at the current time it appears to be a static snowfield. |
It probably is a moraine, but it could also be a protalus rampart
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Ringangleclaw
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| gb wrote: | | Argue away. But explain the moraine below the glacier. |
Protalus rampart
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gb
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gb
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Tue Oct 21, 2014 11:40 am |
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| Ringangleclaw wrote: | | gb wrote: | | Argue away. But explain the moraine below the glacier. |
Protalus rampart |
Nice try. You're still stuck with the crevasses that appear on the glacier in late season - maybe not active now, but….
And the moraine is extensive enough to be easily discernible on the Cascade Pass quadrangle (which doesn't show the ice). Looks like it is at least 80' tall.
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boot up
Old Not Bold Hiker
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boot up
Old Not Bold Hiker
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Tue Oct 21, 2014 11:47 am |
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| Conrad wrote: | | Jeff wrote: | | (maybe all 50?) |
Not all 50. I'm sure Alaska has glaciers that calve right into the ocean. |
But the ocean is higher elevation up there, at least it seems to be per this discussion.
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tigermn
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tigermn
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Tue Oct 21, 2014 11:49 am |
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| boot up wrote: | | But the ocean is higher elevation up there, at least it seems to be per this discussion.
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No doubt. Due to global warming and the polar ice melt the level of the ocean up north is now no longer at sea level... 
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Ringangleclaw
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1) Protalus ramparts can be very large
2) It could have been a glacier in the past, but is now more properly defined as a snowfield
3) Cracks could indicate glacial flow, but could also be bergschrunds or moats. They could also extend thru the snow to rock. The Slesse Glacier is referred to as a glacier by many, and is also criss crossed by many cracks and moats. But I have been there when there was nothing but rock in that cirque.
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