Ice-flow history of Thwaites Glacier, West Antarctica
Project Goals: This
project has a sharply focused scientific goal: to understand the response of
Thwaites Glacier to recent changes at its
grounding line within the context of any possible long-term variability
in mass balance.
To this end, we concentrate on understanding the controls on fast
glacier flow in this
area and search for evidence which allows us to quantify the effect of
recent changes in elevation
and grounding line retreat on margin position within the context of
longer time-scale retreat. Our
plan is to work with data from groups that have previously visited the
region (UTIG and ITASE) and those that are planning upcoming surveys (as part of ICEBridge) for analysis which allows us to test the following
hypotheses related to our goal:
Margin migration: Observed changes in grounding line position and ice
sheet elevation of Thwaites
Glacier have forced outward migration of its lateral margins over the
past few decades indicating
that the basal boundary conditions that permit fast flow are not fixed
in space and time.
Past variability: The divide between Thwaites and Pine Island Glaciers contains
stratigraphy indicating that bounding glaciers have been active but
fixed spatially for several
millenia.
Controls on fast flow: A layer of deformable, wet till (as measured by
increased bed reflectivity)
underlies the fast-moving trunk regions of Thwaites Glacier but not
beneath the slow-moving
ridge between Thwaites and Pine Island Glacier. This wet till permits
fast flow within the
trunk region.
