Dynamic response of an Arctic epishelf lake to seasonal and long-term forcing: implications for ice shelf thickness
Changes in the depth of the freshwater–seawater interface in epishelf lakes have been used to infer long-term changes in the minimum thickness of ice shelves; however, little is known about the dynamics of epishelf lakes and what other factors may influence their depth. Continuous observations c...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-09-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/11/2189/2017/tc-11-2189-2017.pdf |
| Summary: | Changes in the depth of the freshwater–seawater interface in epishelf lakes
have been used to infer long-term changes in the minimum thickness of ice
shelves; however, little is known about the dynamics of epishelf lakes and
what other factors may influence their depth. Continuous observations
collected between 2011 and 2014 in the Milne Fiord epishelf lake, in the
Canadian Arctic, showed that the depth of the halocline varied seasonally by
up to 3.3 m, which was comparable to interannual variability. The seasonal
depth variation was controlled by the magnitude of surface meltwater inflow
and the hydraulics of the inferred outflow pathway, a narrow basal channel in
the Milne Ice Shelf. When seasonal variation and an episodic mixing of the
halocline were accounted for, long-term records of depth indicated there was
no significant change in thickness of ice along the basal channel from 1983
to 2004, followed by a period of steady thinning at 0.50 m a<sup>−1</sup> between
2004 and 2011. Rapid thinning at 1.15 m a<sup>−1</sup> then occurred from 2011 to
2014, corresponding to a period of warming regional air temperatures.
Continued warming is expected to lead to the breakup of the ice shelf and the
imminent loss of the last known epishelf lake in the Arctic. |
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| ISSN: | 1994-0416 1994-0424 |