Thompson Glacier is a spectacular outlet glacier from the Mueller Icecap, about 34 km long and 3 km wide in the ablation area. It runs almost precisely in a north to south direction and receivs a number of major tributary flow units from the mountainous regions of central Axel Heiberg, the lowest being White Glacier. It dams several lakes, one of considerable size, such as Astro Lake and, largest of all, Phantom Lake. Thompson Glacier davanced in the order of 18 metres per year in the 1960ies and 70ies. The advance has decelerated somewhat since and has been in the order of 11 metres per year in the period from 1977 to 2008. Strongly curved medial moraines indicate irregular flow, perhaps even surges, of some of its tributaries. It has a prominent push moraine along most of its frontal margin.
Aerial view of the combined terminus of Thompson and White Glacier (left; August 8th, 1977). Warm weather is causing considerable ablation and, thus, high water level in the strongly braided Expedition River (foreground).
Similar aerial photo from July 2nd, 2008, 31 years after the previous picture was taken. The genral setting remians the same, but White Glacier has receeded considerably, whereas Thompson has advanced.
Confluence of White (left) and Thompson Glacier as seen on August 8th, 1977. In the 1960ies and 70ies, Thompson Glacier's western front had a prominent ice cliff. Advance was by frequent cliff collapse and overriding of the ice debris, well visible in the right foreground.
Ice blocks from cliff collapse events in front of Thompson Glacier's western front, spring 1976. At the centre, ice debris has filles, and is blocking, the meltwater channel eroded during the previous year's outburst flood from Between Lake.
Ice debris which has fallen from Thompson Glacier's advancing cliff, lying ontop of the easternmost part of White Glacier's terminal moraine (spring 1976). Little Matterhorn (left) and Bastion Ridge in the background.
By July 8th, 2008 the morphology of Thompson Glacier's terminus has changed considerably, particularly in the western part: it is much flatter (but still very impressive), and a narrow band of moraine has developped.
Spectacular waterfall, fed by an englacial meltwater stream, emerging from Thompson Glacier's front. Its position must be relatively stable as it has eroded and removed the ice-cored terminal moraine, parts of which remain visible on the left and right (July 16th, 2008).
Detail of the waterfall (July 16th, 2008). Note that this photo was taken on a cold day when comparatively little water emerged. This location could only reached when runoff from White Glacier was greatly reduced and the meltwater streams could be crossed safely.
Stereo anaglyph of the waterfall. Red-blue or red-cyan glasses are needed to see the stereoscopic effect. Note the deep incision of the ice by the righthand part of the fall and prominent folding of ice structures on the lower right (July 16th, 2008).
Stereo anaglyph image of Thomson Glacier (centre) and White Glacier (left, red-blue or red-cyan glasses needed), photos taken in August 1977 from points about 1km SSW of the summit of White Glacier Hill. Note the vertical cliff at the front of Thompson Glacier.
Strongly curved medial moraines on Tompson Glacier indicate irregular inflow of ice from tributary glaciers. In the background the view goes up the entire length of White Glacier (approximately 14 kilometres; July 2nd, 2008).
View along the entire length of Thompson Glacier, i.e. approximately 30 kilometres. In the right foreground is the deep meltwater channel from Astro Lake (July 2nd, 2008).
Detail of the meltwater channel from Astro Lake: At centre the roof has collapsed and the water is just barely visible. On the upper right and lower left the channel is closed.
On an overcast day the colours of these supraglacial meltwater channels on Thompson Glacier is particularly striking.
Meadering meltwater channels and ponds on Thompson Glacier. The main channel is several metres wide and could not be crossed on foot.
Striking meltwater ponds on Thompson Glacier between Astro and Phantom Lake. The bottom of the ponds appears black due to cryoconite deposits.
Thompson Glacier east of Zebra Mountain. Note brown sediment transported on to the glacier by a prominet meltwater stream. Behind the mountains in the background is White Glacier (July 2nd, 2008).
Aptly named Parallel Glacier, Thompson Glacier (left) and Mueller Ice Cap in the distance. Note the synclinal folding of the rock on the right (August 8th, 1977).
Zebra Mountain, one of the most striking geological features in the catchment basin of Thompson Glacier. Small ice-dammed lakes are at its base (August 8th, 1977).
Ablation has been strong, even in the upper parts of Thompson Glacier in summer 2008, so many crevasses are exposed and steep rock faces snowfree (July 2nd, 2008).
|Photos Jürg Alean|