Diurnal and semidiurnal tide-induced lateral movement of Ronne Ice Shelf, Antarctica

Recent GPS observations from a spatially extensive networkacross Ronne Ice Shelf show significant daily ice flowvariations. At all sites, the almost-synchronous horizontaldisplacements occur at diurnal and semidiurnal tidal periods.During spring tides, displacements, velocities and strains nearthe i...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Makinson, K, King, MA, Nicholls, KW, Gudmundsson, GH
Format: Article in Journal/Newspaper
Language:English
Published: Wiley-Blackwell Publishing 2012
Subjects:
Online Access:https://doi.org/10.1029/2012GL051636
http://ecite.utas.edu.au/89656
Description
Summary:Recent GPS observations from a spatially extensive networkacross Ronne Ice Shelf show significant daily ice flowvariations. At all sites, the almost-synchronous horizontaldisplacements occur at diurnal and semidiurnal tidal periods.During spring tides, displacements, velocities and strains nearthe ice front have superimposed oscillations that are +-300%of their mean values and occur over a six-hour period, resultingin regular ice shelf flow reversals. Close to ice streamgrounding lines, however, the horizontal diurnal and semidiurnalsignals decay and almost vanish. From our analysis,we conclude that ice shelves respond primarily elasticallyto tidal tilting, thus accounting for the observed diurnal andsemidiurnal flow variations, and their amplification towardthe ice shelf front. Our findings suggest that detailed modelingof these data could provide improved ice shelf and icestream models for correctly simulating ice shelf flow andpredicting future ice sheet evolution.