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Australia: The Land Where Time Began |
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Totten Glacier, East Antarctica - Ocean Access to a Cavity Beneath it The largest rate of thinning in East Antarctica is
occurring at the Totten Glacier, which is the primary outlet for the
Aurora Subglacial Basin (Flament & Rémy, 2012; Pritchard et
al., 2009). According to
Greenbaum et
al. thinning may
be driven by enhanced melting at the base as a result of ocean processes
(Pritchard, 2012), that are modulated by polynya activity (Gwyther et
al., 2012; Khazender et
al.,
2013). Warm modified Circumpolar Deep Water, which has been linked to
glacier retreat in West Antarctica (Jenkins et al., 2010), has been
observed in summer and winter on the nearby continental shelf beneath
400-500 m of cool Antarctic Surface Water (Bindoff, Rosenberg & Warner,
2000; Williams et
al., 2011).
In this paper Greenbaum et
al.
derived a bathymetry of the sea floor in the region (Parker, 1973) by
the use of gravity data and magnetics data (Aitken et
al., 2014) as well as
measurements of ice thickness (Young et
al., 2011). They identified
entrances to the ice shelf cavity below depths of 400-500 m that could
allow warm water to intrude if the vertical flow is similar to nearby
observations. It was revealed by radar sounding that an inland trough,
that had not previously been known, connects the main ice shelf cavity
to the ocean. They suggest that if thinning trends continue a larger
water body over the trough could potentially allow warm water to enter
the cavity which may eventually result in destabilisation of the
low-lying region between Totten Glacier and the glacier, that is
similarly deep, that flows into the Reynolds Trough. Greenbaum et
al. estimate that at least
3.5 m of eustatic sea level potential drains through the Totten Glacier,
therefore coastal processes in this area could result in global
consequences.
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Author: M.H.Monroe Email: admin@austhrutime.com Sources & Further reading |