For Hyak: Photos of glacial recession on Mt Hood?

A dissenting perspective from Hyak's Hood photos , here is the west side of Mt Hood published by the *BBC* today:<br> <br><br>From news.bbc.co.uk/1/shared/spl/hi/picture_g..._changing/html/5.stm

Nice pictures. You need to be careful interpreting them though. The 1985 shot looks like it was taken earlier in the summer, so there is quite a bit of seasonal snow still around. The actual extent of the glaciers (as well as I can tell by looking at the pictures) hasn't changed too much. The snow and ice on the headwalls (particularly the Sandy) is very different, but I don't think that really counts. I've got a similar picture of Spider Mountain on my website:<br><br> www.alpenglow.org/climbing/ptarmigan-195...r-mtn-1953-2003.html

That certainly seems like good advice, Lowell. FWIW, the caption of the photo is, "This image shows Mount Hood in Oregon at the same time in late summer in 1985 and 2002".<br><br>The full BBC slideshow can be seen here:<br> news.bbc.co.uk/1/shared/spl/hi/picture_g..._changing/html/1.stm

The slideshow starts out with the text:

Some scientists say an increase in the rate of melting of the world's glaciers is evidence of global warming. <br><br>Argentina's Upsala Glacier was once the biggest in South America, but it is now disappearing at a rate of 200 metres per year. <br><br>Other scientists say its reduction is due to complicated shifts in glacial dynamics and local geology.

<br>I'm certainly not a scientist nor do I have any background in glaciology, this leaves me stuck with taking the interpretation of whatever source seems most credible.

The Robson glacier (Mt. Robson, B.C.) is receding about 50 ft. a year. It's amazing to see the height of the lateral moraines. I'm too lazy to look it up, but aren't there only a couple of glaciers in the world that are actually growing? I sort of remember reading that the Blue on Olympus was one of them. ???

My UW geodork buddies tell me the Blue is one of the few that is stagnant, mostly due to a steep gradient at its terminus. It would need much higher temps to recede and much cooler temps to advance. The glacier inside the Mt St Helens crater is actually growing because the eruption created a new "cirque" of sorts without any ice in it, and the whole system is still way out of whack because of that. At some point it should reach equlibrium (I'm sure there's a masters thesis or two there...). Of course, it could also just get blown up...

Unless all glaciologists are corrupt, I do not doubt that most glacial "regions" are rapidly losing mass. A documented fact and indisputable. This includes the Cascades.<br><br>However, the type of glacier that is to react most to this phenomenon may not be consistent. The small hanging and pocket glaciers that are high on the sides of the Cascades may be particularly immune to what is happening. This may be due to their very nature, they can only accumulate a certain amount of mass in a given season because of their physical constraints (small area confined by steep slopes, steep accumulation zones, etc.) Once they accumulate max snow in a season, the rest just sloughs off to the sides or drops far below. In other words they max out in lean or mean years no matter what. Many of the pictures shown in these discussions seem to concentrate on displaying this type of glacier, which is so common in the Cascades, yet still does not represent where most of the glacial mass resides.<br><br>Larger glaciers with lower angle accumulation zones, would seem to be most vunerable. Here are glaciers that have esssentially no limits to their ability to accumulate snow in a given season, have done so for centuries or more to attain some level of equilibrium and therefore will react most dramatically to a consistent change in their ability to maintain mass. Can anyone argue that the Nisqually is actually increasing in mass or is stable? Even the Coleman, which recently was advancing (which by the way does not necessarily mean that it is increasing in mass, it could be that the bed that the glacier is resting on has increased in lubrication due to melting that causes a surge in forward motion.) has clearly changed for the less since my ventures there in 1993. The stagnant portion of the Coleman is completely disintegrating, and the active portion in the trench seems to occupy noticably less volume.<br><br>In any case all the dinky pocket glaciers seen on the sides of many mountains of the Cascades probably don't add up to the volume of one or two Nisquallys or Colemans. It could be that the glaciologists measurements reflect total ice depletion and not whether one small glacier here or there is gaining or losing.<br><br>Since the jist of these threads seem to be arguments for or against global warming, my two cents are that the phenomenon is clearly established. I think the only debate at this point is why and will it continue and if so, how far will it go?<br><br>Alan