Manuscript: 2004-12-27872B Holocene Stability of the Larsen

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Manuscript: 2004-12-27872B
Holocene Stability of the Larsen-B Ice Shelf on the Antarctic Peninsula
Supplementary Information
Supplemental Figure 1
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Supplemental Figure 1 Caption: Processed backscatter data from Seabeam® swath map
transect (Fig. 1B, original text) in LIS-B embayment. Shading highlights streamlined
seafloor features parallel to bathymetric contours (Fig. 1B, original text) at a variety of
scales consistent with flutes and mega-scale glacial lineations (bundles), all formed
subglacially parallel to glacial flow.
Supplemental References: references critical to the glacial reconstruction as shown in
text (Fig. 1A) are as follows.
Backman, E. C., Depositional architecture and seafloor mapping of the Vega Drift,
Erebus and Terror Gulf, Antarctic Peninsula. BA thesis, Hamilton College, Clinton, NY,
58 pp (2003).
Backman, E. C., & Domack, E., Depostional architecture and seafloor mapping of the
Vega Drift, Erebus and Terror Gulf, Antarctic Peninsula. Eos Trans. AGU, 84 (46), Fall
Meet. Suppl., Abstract PP31B-0256 (2003).
Camerlenghi, A., Domack, E., Rebesco, M., Gilbert, R., Ishman, S., Leventer, A.,
Brachfeld, S. and Drake, A., Glacial morphology and post-glacial contourites in northern
Prince Gustav Channel (NW Weddell Sea, Antarctica). Mar. Geoph. Res. 22, 417 (2002).
Canals, M., Urgeles, R., & Calafat, T. Deep sea-floor evidence of past ice streams
off the Antarctic Peninsula. Geol. 28, 31 (2000).
Canals, M ., et al., Seafloor evidence for a subglacial sedimentary system off the
northern Antarctic Peninsula. Geol. 30, 603 (2002).
Domack, E. W. et al., Subglacial morphology and glacial evolution of the Palmer
Deep outlet system, Antarctic Peninsula. Geomorph. (in press). Available on line at:
http://academics.hamilton.edu/geology/edomack/Domack-in-press.pdf
Evans, J. et al., Late Quaternary glacial history, flow dynamics and sedimentation along
the eastern margin of the Antarctic Peninsula Ice Sheet. Quat. Sci. Rev., 24, 741-774
(2005).
Gilbert, R., Domack, E. W., Camerlenghi, A. Deglacial history of the Greenpeace
Trough: ice sheet to ice shelf transition in the northwestern Weddell Sea. Ant. Res.
Ser. 79,195-204 (2003).
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Supplemental Figure 2: Grain proportions for coarse sand and granules sampled from
core KC-5. The data demonstrate shifting provenance between stratigraphic units 1, 2
and 3 with a loss of intrabasinal grains of shale, siltstone, and sandstone (bold font) as
material becomes more distally derived beneath the ice shelf (unit 1). This shift
corresponds to a change in debris source from basal debris (units 3 and base of unit 2) to
englacial (upper unit 2 and unit 1), the later of which is derived from tributary sources
along the Antarctic Peninsula (see Fig. 1A in original text). Note absence of any volcanic
detritus indicative of extrabasinal iceberg sources.
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