Towards a description of stick-slip motion using a viscoelastic Full Stokes model 

2021 ◽  
Author(s):  
Cristina Gerli ◽  
Sebastian Rosier ◽  
Hilmar Gudmundsson
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Element Model ◽  
Stick Slip ◽  
Ice Stream ◽  
Basal Sliding ◽  
Rate And State Friction ◽  
Set Up ◽  
Stick Slip Motion ◽  
Slip Motion

<p>The lightly grounded portion of the Whillans Ice Stream (WIS, Siple Coast, Antarctica), has a unique stick-slip motion behaviour, where prolonged stagnant phases (6-25 hrs) are interrupted by rapid active slip events (up to 0.5 m in < 1 hr).  WIS is also interesting because it is currently stagnating, presenting an important opportunity to understand this behaviour and its effect on future sea level rise. Detailed observations and a variety of modelling approaches have revealed the complexity of stick-slip behaviour and the importance of correctly representing ice rheology, ice stream geometry, spatial variability of friction strength, and boundary conditions. Currently, no single model exists that can fully replicate all the observed features of stick-slip motion as observed on the Whillans Ice Plain. Here we describe a full-Stokes viscoelastic finite element model that has been previously used to explore tidal modulation of ice stream flow, and which can overcome some of the assumptions adopted in previous work. The model is  set up for an idealised configuration of the Whillans Ice Plain, with the aim of exploring how the inclusion of relevant additional physics affects stick-slip motion for a rate and state friction law, and whether other sliding laws could also explain the observed motion. Ultimately, this modelling work aims to put tighter constraints on the conditions required to initiate stick-slip behaviour, improving our understanding of basal sliding and future sea level rise.</p>

Dynamics of stick–slip motion, Whillans Ice Stream, Antarctica

2011 ◽  
Vol 305 (3-4) ◽  
pp. 283-289 ◽  
Author(s):  
J. Paul Winberry ◽  
Sridhar Anandakrishnan ◽  
Douglas A. Wiens ◽  
Richard B. Alley ◽  
Knut Christianson
Keyword(s):  
Stick Slip ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Stick Slip Motion ◽  
Slip Motion

scholarly journals Basal mechanics of ice streams: Insights from the stick-slip motion of Whillans Ice Stream, West Antarctica

2009 ◽  
Vol 114 (F1) ◽  
Author(s):  
J. Paul Winberry ◽  
Sridhar Anandakrishnan ◽  
Richard B. Alley ◽  
Robert A. Bindschadler ◽  
Matt A. King
Keyword(s):  
West Antarctica ◽  
Ice Streams ◽  
Stick Slip ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Stick Slip Motion ◽  
Slip Motion

Simultaneous teleseismic and geodetic observations of the stick–slip motion of an Antarctic ice stream

Nature ◽  
2008 ◽  
Vol 453 (7196) ◽  
pp. 770-774 ◽  
Author(s):  
Douglas A. Wiens ◽  
Sridhar Anandakrishnan ◽  
J. Paul Winberry ◽  
Matt A. King
Keyword(s):  
Stick Slip ◽  
Ice Stream ◽  
Stick Slip Motion ◽  
Slip Motion

scholarly journals Stick–slip behavior of ice streams: modeling investigations

2009 ◽  
Vol 50 (52) ◽  
pp. 87-94 ◽  
Author(s):  
Olga V. Sergienko ◽  
Douglas R. MacAyeal ◽  
Robert A. Bindschadler
Keyword(s):  
West Antarctica ◽  
Ice Streams ◽  
Stick Slip ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Spatial Propagation ◽  
The Difference ◽  
Stick Slip Motion ◽  
Transitional Phase ◽  
Slip Motion

AbstractA puzzling phenomenon of ice-stream flow is the stick–slip motion displayed by Whillans Ice Stream (WIS), West Antarctica. In this study we test the hypothesis that the WIS stick–slip motion has features similar to those of other known stick–slip systems, and thus might be of the same origin. To do so, we adapt a simple mechanical model widely used in seismology to study classic stick–slip behavior observed in tectonic faults, in which the difference between static and dynamic friction allows for the generation and spatial propagation of abrupt slip events. We show how spatial variability in friction properties, as well as a periodic forcing intended to mimic the effect of tides, can reproduce the observed duration and periodicity of stick–slip motion in an ice stream. An intriguing aspect of the association of WIS with mechanical stick–slip oscillators is that the onset of stick–slip cycling from a condition of permanent slip appears to be associated with the reduction in overall speed of WIS. If this association is true, then stick–slip behavior of WIS is a transitional phase of behavior associated with the ice stream's recent deceleration.

scholarly journals A Viscoelastic Model of Ice Stream Flow with Application to Stick-Slip Motion

2016 ◽  
Vol 4 ◽  
Author(s):  
Ryan T. Walker ◽  
Byron R. Parizek ◽  
Richard B. Alley ◽  
Sophie M. J. Nowicki
Keyword(s):  
Stream Flow ◽  
Viscoelastic Model ◽  
Stick Slip ◽  
Ice Stream ◽  
Stick Slip Motion ◽  
Slip Motion

scholarly journals Tidally driven stick–slip motion in the mouth of Whillans Ice Stream, Antarctica

2003 ◽  
Vol 36 ◽  
pp. 263-272 ◽  
Author(s):  
Robert A. Bindschadler ◽  
Patricia L. Vornberger ◽  
Matt A. King ◽  
Laurie Padman
Keyword(s):  
High Tide ◽  
Spring Tide ◽  
Shear Stresses ◽  
Motion Events ◽  
Stick Slip ◽  
Ice Stream ◽  
Whillans Ice Stream ◽  
Stick Slip Motion ◽  
Tide Period ◽  
Slip Motion

AbstractWe show that the ice plain in the mouth of Whillans Ice Stream (formerly Ice Stream B), Antarctica, moves by stick–slip motion. During a spring-tide period, rapid motions regularly occur near high tide and during falling tide. This correlation is weaker during a neap-tide period when the tidal magnitudes are less. Precise timing of these motion events suggests that they propagate through the region with a mean velocity of 88 m s−1.We hypothesize that this speed is associated with the propagation of shear waves through a wet subglacial till. Motion events are also seen on more smoothly flowing floating ice. Event delays are very short between grounded and floating stations, suggesting the events propagate through the ice shelf as an elastic wave. We further hypothesize the events are caused by the interaction of a sticky bed, the accumulation of stored elastic strain through the compression of ice by upstream inflow, and tidal forcing. Motion events seem to be triggered either by reduction of vertical normal stresses at high tide or by the increase of shear stresses from sub-shelf ocean currents during falling tide. Event magnitudes are not related to the length of the preceding quiescent period, suggesting significant viscous dissipation within the till.

scholarly journals Friction and slip measured at the bed of an Antarctic ice stream

2022 ◽  
Author(s):  
Thomas Hudson ◽  
Sofia-Katerina Kufner ◽  
Alex Brisbourne ◽  
Michael Kendall ◽  
Andrew Smith ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Shear Stresses ◽  
Stick Slip ◽  
Ice Dynamics ◽  
Slip Rates ◽  
Effective Normal Stress ◽  
Ice Stream ◽  
Basal Shear ◽  
Dynamics Models

Abstract The slip of glaciers over the underlying bed is the dominant mechanism governing the migration of ice from land into the oceans, contributing to sea-level rise. Yet glacier slip remains poorly understood or constrained by observations. Here we observe both frictional shear-stress and slip at the bed of an ice stream, using 100,000 repetitive stick-slip icequakes from Rutford Ice Stream, Antarctica. Basal shear-stresses and slip-rates vary from 10^4 to 10^7 Pa and 0.2 to 1.5 m day^(-1), respectively. Friction and slip vary temporally over the order of hours and spatially over 10s of meters, caused by corresponding variations in ice-bed interface material and effective-normal-stress. Our findings also suggest that the bed is substantially more complex than currently assumed in ice stream models and that basal effective-normal-stresses may be significantly higher than previously thought. The observations also provide previously unresolved constraint of the basal boundary conditions of ice dynamics models. This is critical for constraining the primary contribution of ice mass loss in Antarctica, and hence the endeavour to reduce uncertainty in sea-level rise projections.

Stick-slip motion of an Antarctic Ice Stream: The effects of viscoelasticity

2014 ◽  
Vol 119 (7) ◽  
pp. 1564-1580 ◽  
Author(s):  
D. N. Goldberg ◽  
C. Schoof ◽  
O. V. Sergienko
Keyword(s):  
Stick Slip ◽  
Ice Stream ◽  
Stick Slip Motion ◽  
Slip Motion
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