I’ve written a lot in my blog postings about snowfields that persist in mountainous regions at high altitudes into the summer months (and beyond), but there is a related phenomenon that I have only recently become aware of, and that is of winter ice persisting into the summer months in rock fissures (or fractures) and caves. These fissures can exist at any elevation and not necessarily in mountainous areas, and can provide a remarkably sheltered local environment deep within them that can collect snowfall in the winter months but are largely unaffected by the surrounding climatic conditions. Something related to these fissures is a geological feature known as an ‘Algific talus slope‘ although this is something that is new to me, but they seem to be, in effect, natural subterranean freezers!
Rock fissures which contain snow and ice well into the summer is a feature I first came across when I went hiking in New York State in 2004. New York State (and New England in general) gets a lot of snow in the winter months, but the mountains are not of great height and the summer months are very warm. There is no glacial ice anywhere in the region and to the best of my knowledge perennial or long-lasting snow in the area is extremely rare.
There are three places in the north-eastern continental USA where snow and ice is reputed to exist in rock fissures throughout the year, although I have not seen any accounts or photographs showing snow in these areas beyond July (I haven’t visited these areas on my hiking trips to the region). Details of the three areas are given below. The third area on the list is remarkable in being at such a low altitude and latitude, and being only a couple of hours drive from central New York City! As far as I know, these three areas are the only areas in the continental US east of the Rockies that may contain snow well into the summer months, and you probably have to go as far north as the mountains of coastal Labrador to find some true perennial or glacial snow/ice on this side of North America.
I have often wondered whether such fissures might exist in the Scottish mountains but I think there is nothing like this, the geology of the upland areas is not right, the only area of significant limestone where this sort of thing appears in northern Scotland is (I think) around Inchnadamph in the north-west. There is an SMC photograph from 1899 of deep summer snow that looks like it was taken in the ‘Window’, just north of the summit plateau of Creag Meagaidh. The Window is almost a very large fissure in its general shape, so the area might well behave like the rock fissures mentioned above, although I suspect the depth of snow contained within it is highly dependent on the prevailing winter wind direction. I remember stopping in the Window a few years ago for lunch and being impressed by its ‘walled-in’ and claustrophobic situation.
There is also tantalising evidence in historical accounts of snow existing at remarkably low elevations in fissures into the summer months in England. Of course, exaggeration is often present in old accounts, but it’s still very intriguing.
Locations in the north-eastern USA where summer ice may be present in rock fissures:
1. Mount Adams Ice Caves/King Ravine, Presidential Range, White Mountains, New Hampshire
Altitude (of ice caves in ravine): approx. 1200m asl
Latitude: approx. 44°N
2. Ice Cave Mountain, Adirondacks, New York
Altitude (of fissures): approx. 750m asl
Latitude: approx. 43°N
http://www.birdheadstudios.com/html/pics/adk/icecave01.htm (photos from May?)
http://www.adkforum.com/photos/v/mavs00/Ice-cave/ (photos from 22 July 2007)
3. Ellenville Fault Ice Caves, Shawangunk Ridge, Catskills, New York
Altitude (of ice caves): approx. 650m asl
Latitude: approx. 41°N
http://outdoors.webshots.com/photo/1078333250029688058xLCOZG (photos from 24 June?)