Ice-shelf tidal flexure and subglacial pressure variations

被引：78

作者：

Walker, Ryan T. ^{[1
,2
]}

Parizek, Byron R. ^{[3
]}

Alley, Richard B. ^{[1
,2
]}

Anandakrishnan, Sridhar ^{[1
,2
]}

Riverman, Kiya L. ^{[1
]}

Christianson, Knut ^{[4
]}

机构：

[1] Penn State Univ, Dept Geosci, University Pk, PA 16802 USA

[2] Penn State Univ, Earth & Environm Syst Inst, University Pk, PA 16802 USA

[3] Penn State DuBois, Math & Geosci, Du Bois, PA 15801 USA

[4] St Olaf Coll, Dept Phys, Northfield, MN 55057 USA

来源：

EARTH AND PLANETARY SCIENCE LETTERS | 2013年 / 361卷

基金：

美国国家科学基金会;

关键词：

ice shelf; tidal flexure; subglacial hydrology; GROUNDING ZONE; ANTARCTICA; STREAM; DYNAMICS; GLACIER; LINE; DRIVEN; INSAR; MODIS; FLOW;

D O I：

10.1016/j.epsl.2012.11.008

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

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 (similar to 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. (C) 2012 Elsevier B.V. All rights reserved.

引用

页码：422 / 428

页数：7

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