A viscoelastic model of ice stream flow with application to stick-slip motion

Frontiers in Earth Science

Ryan Thomas Walker¹  Sophie eNowicki¹  Byron eParizek²  Richard eAlley³ 

[1] NASA Goddard Space Flight Center;Penn State DuBois;Pennsylvania State University;University of Maryland;

关键词: viscoelasticity;    STICK-SLIP;    Ice rheology;    Whillans Ice Stream;    ce stream dynamics;    numerical ice sheet modeling;   

DOI  :  10.3389/feart.2016.00002

来源: DOAJ

【 摘 要 】

Stick-slip motion such as that observed at Whillans Ice Stream, WestAntarctica, is one example of transient forcing significantly affecting longer-termice-stream dynamics. We develop and present a two-dimensional map-plane viscoelasticmodel of perturbations to ice-stream dynamics suitable for simulating andanalyzing stick-slip behavior. Model results suggest important roles in stick-slipmotion for both the elastic and viscous components of ice rheology, confirming andextending inferences drawn from simple models and observations. Elastic behaviordepends on the rate of applied stress, at times allowing significant velocity perturbationswith little change in accumulated stress perturbation; in contrast, viscousbehavior depends on total accumulated stress and can lead to changes in ice-streamthickness over many stick-slip cycles.

【 授权许可】

Unknown