Abstract
ABSTRACTIce shelves regulate the rate of ice-sheet discharge along much of the Antarctic coastline. Pinning points, sites of localised grounding within floating ice, can in turn, regulate the flow and thickness of an ice shelf. While the net resistive effect of ice shelves has been quantified in a systematic way, few extant pinning points have been examined in detail. Here, complete force budgets are calculated and examined for ice rises and rumples in the Ross Ice Shelf, West Antarctica. The diverse features have different effects on ice shelf mechanics that do not depend simply on their size but may, we conclude, depend on the properties of seafloor materials.
Highlights
The floating ice shelves surrounding much of the Antarctic coastline limit mass flux from the interior of the continent (Thomas, 1979; Dupont and Alley, 2006)
Using a force budget approach, we quantified the magnitude and direction of drag forces generated by 15 pinning points and pinning point complexes within the Ross Ice Shelf (RIS)
Variations in the subglacial material appear to play an important role in determining the effective resistance generated by each feature
Summary
The floating ice shelves surrounding much of the Antarctic coastline limit mass flux from the interior of the continent (Thomas, 1979; Dupont and Alley, 2006). The effective resistance generated by each of the RIS pinning points can be quantified using a local force budget calculation (MacAyeal and others, 1987) In this approach, the net traction vector acting on an imaginary contour Γ surrounding the pinning point and its associated grounded ice is partitioned into form drag and dynamic drag components estimated from observed quantities. Uncertainty in the force budget calculation arises from (1) the errors in the velocity data and strain rates calculated from velocity gradients; (2) error in the GLAS 500 m DEM and inferred ice shelf thickness; and (3) the estimated B value (Table 1). Each contour encloses the surface features, small areas of floating ice shelf surrounding the pinning point, and any regions of crevassing originating from the ice rise or rumple. The contact area is not observable so it is approximated as the surface area of the ice rumple
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
