TY - JOUR
T1 - Ice-shelf tidal flexure and subglacial pressure variations
AU - Walker, Ryan T.
AU - Parizek, Byron R.
AU - Alley, Richard B.
AU - Anandakrishnan, Sridhar
AU - Riverman, Kiya L.
AU - Christianson, Knut
N1 - Funding Information:
All authors were supported by the Center for Remote Sensing of Ice Sheets (CReSIS) under NSF Grant 0424589 . R.T.W. and B.R.P. were supported by NSF Grant 0909335 and NASA Grants NNX-09-AV94G and NNX-10-AI04G . B.R.P. was also supported by NSF Grant 0758274 . We thank the editorial staff and two anonymous reviewers for their efforts.
PY - 2013/1/1
Y1 - 2013/1/1
N2 - We develop a model of an ice shelf-ice stream system as a viscoelastic beam partially supported by an elastic foundation. When bedrock near the grounding line acts as a fulcrum, leverage from the ice shelf dropping at low tide can cause significant (~ 1 cm) uplift in the first few kilometers of grounded ice. This uplift and the corresponding depression at high tide lead to basal pressure variations of sufficient magnitude to influence subglacial hydrology. Tidal flexure may thus affect basal lubrication, sediment flow, and till strength, all of which are significant factors in ice-stream dynamics and grounding-line stability. Under certain circumstances, our results suggest the possibility of seawater being drawn into the subglacial water system. The presence of seawater beneath grounded ice would significantly change the radar reflectivity of the grounding zone and complicate the interpretation of grounded versus floating ice based on ice-penetrating radar observations.
AB - We develop a model of an ice shelf-ice stream system as a viscoelastic beam partially supported by an elastic foundation. When bedrock near the grounding line acts as a fulcrum, leverage from the ice shelf dropping at low tide can cause significant (~ 1 cm) uplift in the first few kilometers of grounded ice. This uplift and the corresponding depression at high tide lead to basal pressure variations of sufficient magnitude to influence subglacial hydrology. Tidal flexure may thus affect basal lubrication, sediment flow, and till strength, all of which are significant factors in ice-stream dynamics and grounding-line stability. Under certain circumstances, our results suggest the possibility of seawater being drawn into the subglacial water system. The presence of seawater beneath grounded ice would significantly change the radar reflectivity of the grounding zone and complicate the interpretation of grounded versus floating ice based on ice-penetrating radar observations.
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U2 - 10.1016/j.epsl.2012.11.008
DO - 10.1016/j.epsl.2012.11.008
M3 - Article
AN - SCOPUS:84872293727
SN - 0012-821X
VL - 361
SP - 422
EP - 428
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -