Recent changes in the flow of the Ross Ice Shelf, West Antarctica

Comparison of surface velocities measured during the Ross Ice Shelf Geophysical and Glaciological Survey (RIGGS, 1973 to 1978) and velocities measured via feature tracking between two Moderate-resolution Imaging Spectroradiometer (MODIS) mosaics (compiled from 2003/4 and 2008/9 images) reveals wides...

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Bibliographic Details
Published in:Earth and Planetary Science Letters
Main Authors: Hulbe, Christina L., Scamobs, Ted A., Lee, Choon-Ki, Bohlander, Jennifer, Harran, Terry
Format: Article in Journal/Newspaper
Language:English
Published: Elsevier 2014
Subjects:
West Antarctica
Ross Ice Shelf
glacier change
remote sensing
modeling
Crary Ice Rise
Kamb Ice Stream
MacAyeal Ice Stream
Mercer
Whillans
Whillans Ice Stream
Antarc*
Antarctica
Ice Shelf
Online Access:http://hdl.handle.net/10523/4553
https://doi.org/10.1016/j.epsl.2013.06.013
Description
Summary:Comparison of surface velocities measured during the Ross Ice Shelf Geophysical and Glaciological Survey (RIGGS, 1973 to 1978) and velocities measured via feature tracking between two Moderate-resolution Imaging Spectroradiometer (MODIS) mosaics (compiled from 2003/4 and 2008/9 images) reveals widespread slowing and minor areas of acceleration in the Ross Ice Shelf (RIS) over the approximately 30 year interval. The largest changes (−13 ma−2) occur near the Whillans and Mercer Ice Streams grounding line in the southernmost part of the ice shelf. Speed has increased over the interval (up to 5 ma−2) between the MacAyeal Ice Stream grounding line and the shelf front, and along the eastern shelf front. Changes in ice thickness computed using ICESat laser altimetry are used together with a well-tested model of the ice shelf to investigate underlying causes of change in the flow of the ice shelf over time. The observed transients represent a combination of recent forcings and ongoing response to ice stream discharge variations over the past millennium. While evidence of older events may be present, the modern signal is dominated by shorter time scale events, including the stagnation of Kamb Ice Stream about 160 years ago, recent changes in basal drag on the Whillans Ice Stream ice plain and, perhaps, iceberg calving. Details in embayment geometry, for example the shallow sea floor below Crary Ice Rise, modulate the spatial pattern of ice shelf response to boundary condition perturbations. Peer Reviewed

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