Between Lake is an ice-dammed lake between Thompson and White Glacier. In the 1960ies and 70ies it went through an annual cycle of filling in spring, overflowing over the tongue of White Glacier in summer, thereby eroding a deep meltwater channel into the ice and more or less emptying. It was central to an extensive study of ice-dammed lakes in central Axel Heiberg (Maag, H. U., 1969: Ice dammed lakes and marginal glacial drainage on Axel Heiberg Island. McGill University, Axel Heiberg Island Research Report). Due to the recession of White Glacier the ice barrier has become insufficient to provide enough damming, so that cycles of filling and emptying no longer occur (2008). All photos below are from 1977, when annual draining still took place (see also repeat photos 1977-2008).
Between Lake is dammed between Thompson Glacier (left background) and White Glacier (right). Small floes of lake ice from the previous winter are still floating on the lake. The overflow will take place at top right.
The lake as seen from a similar position as in the previous photo, but looking more towards the left. Thompson Glacier is forming a cliff where it dams the lake.
Cliff of Thompson Glacier and basal debris at Between Lake. Early in the season the lake level is still very low. Some ice blocks have calved from the glacier.
As spring brings warmer temperatures and snowmelt, Between Lake is gradually filling. Note that still several islands are visible within the lake. Little Matterhorn and Bastion Ridge are in the background.
Near the time of overflowing: all but one island have nearly been submerged.
Between Lake near its highest level. Draining has just started (note strand line along White Glacier).
As draining starts, small floes of lake ice get stranded along Between Lake's shore (photo taken at midnight).
The start of the draining of Between Lake becomes evident by the strand line at the bottom of Thompson Glacier's cliff.
The lake level drops rapidly within hours: The strand line is higher above the lake surface, and Thompson Glacier's basal debris becomes exposed.
The outflow channel first leads over the tongue of White Glacier, but then becomes englacial as the water exploits a tunnel left over from the previous year (1976).
The outburst flood as seen in front of the terminus of Thompson Glacier.
As the outburst flood subsides, ice blocks are left lying on the proglacial gravel deposits.
|Photos Jürg Alean, 1977|