S. Tulaczyk | University of California, Santa Cruz (original) (raw)

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Papers by S. Tulaczyk

Research paper thumbnail of Active Subglacial Lakes and Their Influence on Ice Stream Dynamics

Quaternary International, 2012

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Research paper thumbnail of Origin and Internal Radar Structure of Ice Stream Bedforms from Nunavut, Canada

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Research paper thumbnail of Subglacial lake sediments and sedimentary processes: Potential archives of ice sheet evolution, past environmental change, and the presence of life

Geophysical Monograph Series, 2000

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Research paper thumbnail of Probing Subglacial Environments Under the Whillans Ice Stream

Eos, Transactions American Geophysical Union, 2010

ABSTRACT

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Research paper thumbnail of Changes in Properties of Sub-Ice-Stream Tills Induced by Basal Freeze-On: Theoretical Analysis and Testable Predictions

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Research paper thumbnail of A Mini-Surge on theRyder Glacier, Greenland Observed via Satelite Radar Interferometry

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Research paper thumbnail of (abstract) A Mini-Surge on the Ryder Glacier, Greenland

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Research paper thumbnail of Spatial Patterns of Long-Term Erosion Rates Beneath the Marine West Antarctic Ice Sheet: Insights into the Physics of Continental Scale Glacial Erosion from a Comparison with the Ice-Velocity Field

ABSTRACT

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Research paper thumbnail of Melt beneath the Siple Coast ice streams

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Research paper thumbnail of History of Debris-bearing Basal ice: Comparing Numerical Simulations of Basal Freeze-on to Borehole Video Images and Laboratory Experiments

ABSTRACT

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Research paper thumbnail of Geodesy and Gravity/Tectonophysics (ETG)-ETG 19-Response of subglacial sediments to basal freeze-on 1. Theory and comparison to observations from beneath the West Antarctic Ice Sheet (DOI

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Research paper thumbnail of IceMole-a maneuverable probe for clean in-situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems: extended abstract/SCAR Open Science Conference 2012, Session 29: Advancing Clean Technologies for Exploration of Glacial Aquatic Ecosystems

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Research paper thumbnail of Superimposition of transverse ridges (ribbed moraines) on an ice stream bed: new observations and implications for ice stream dynamics and shutdown

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Research paper thumbnail of Mechanical feedbacks in calving glacier retreat, thinning and acceleration

ABSTRACT

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Research paper thumbnail of First airborne transient EM survey in Antarctica: mapping of saline ground water system

ABSTRACT

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Research paper thumbnail of Temporal Changes in Spatial Distribution of Basal Melting and Freezing in the Catchment Areas of Whillans Ice Stream and Ice Stream C, West Antarctica: Interplay of Climatic Changes and Ice Dynamics

ABSTRACT

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Research paper thumbnail of Numerical modelling of granular subglacial deformation using the discrete element method

ABSTRACT We apply the Discrete Element Method (DEM) to explore the highly nonlinear dynamics of a... more ABSTRACT We apply the Discrete Element Method (DEM) to explore the highly nonlinear dynamics of a granular bed when exposed to stress conditions comparable to warm-based subglacial environments. As a method of validation of the simulated macromechanical behavior, and as a calibration benchmark, we compare results from successive laboratory ring-shear experiments on simple granular materials to results from similar numerical experiments. Overall, there is good agreement between the geotechnical behavior of the materials in the analogue and numerical experiments, and materials deform by an elasto-plastic rheology under the applied effective normal stress and shear velocity. By using the numerical approach it is possible to make a detailed analysis of the material dynamics and shear zone development during progressive shear strain. By visualizing the particles according to the sum of contact forces exerted onto them, the geometry of the heterogeneous stress network is visible in the form of force-carrying grain bridges and adjacent, volumetrically dominant, inactive zones. We demonstrate how the shear zone thickness and dilation is dependent on the effective deviatoric normal stress, where higher stresses mobilize material to greater depths. The data-parallel nature of the basic DEM formulation makes the problem ideal for utilizing the high arithmetic potential of modern general-purpose GPU's. Using the Nvidia Cuda C toolkit, the algorithm is formulated for spherical particles in three dimensions with a linear-elastic soft-body contact model.

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Research paper thumbnail of Sedimentology of mega-scale glacial lineations on the Dubawnt Lake Palaeo-Ice Stream bed, Canada and implications for lineation genesis

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Research paper thumbnail of California's Snow Gun and its implications for mass balance predictions under greenhouse warming

Precipitation has received limited treatment in glacier and snowpack mass balance models, largely... more Precipitation has received limited treatment in glacier and snowpack mass balance models, largely due to the poor resolution and confidence of precipitation predictions relative to temperature predictions derived from atmospheric models. Most snow and glacier mass balance models rely on statistical or lapse rate-based downscaling of general or regional circulation models (GCM's and RCM's), essentially decoupling sub-grid scale, orographically-driven evolution

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Research paper thumbnail of Survey of flow, topography and ablation on NW-Mýrdalsjökull, S-Iceland

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Research paper thumbnail of Active Subglacial Lakes and Their Influence on Ice Stream Dynamics

Quaternary International, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Origin and Internal Radar Structure of Ice Stream Bedforms from Nunavut, Canada

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Subglacial lake sediments and sedimentary processes: Potential archives of ice sheet evolution, past environmental change, and the presence of life

Geophysical Monograph Series, 2000

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Probing Subglacial Environments Under the Whillans Ice Stream

Eos, Transactions American Geophysical Union, 2010

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Changes in Properties of Sub-Ice-Stream Tills Induced by Basal Freeze-On: Theoretical Analysis and Testable Predictions

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A Mini-Surge on theRyder Glacier, Greenland Observed via Satelite Radar Interferometry

Bookmarks Related papers MentionsView impact

Research paper thumbnail of (abstract) A Mini-Surge on the Ryder Glacier, Greenland

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Spatial Patterns of Long-Term Erosion Rates Beneath the Marine West Antarctic Ice Sheet: Insights into the Physics of Continental Scale Glacial Erosion from a Comparison with the Ice-Velocity Field

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Melt beneath the Siple Coast ice streams

Bookmarks Related papers MentionsView impact

Research paper thumbnail of History of Debris-bearing Basal ice: Comparing Numerical Simulations of Basal Freeze-on to Borehole Video Images and Laboratory Experiments

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Geodesy and Gravity/Tectonophysics (ETG)-ETG 19-Response of subglacial sediments to basal freeze-on 1. Theory and comparison to observations from beneath the West Antarctic Ice Sheet (DOI

Bookmarks Related papers MentionsView impact

Research paper thumbnail of IceMole-a maneuverable probe for clean in-situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems: extended abstract/SCAR Open Science Conference 2012, Session 29: Advancing Clean Technologies for Exploration of Glacial Aquatic Ecosystems

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Superimposition of transverse ridges (ribbed moraines) on an ice stream bed: new observations and implications for ice stream dynamics and shutdown

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Mechanical feedbacks in calving glacier retreat, thinning and acceleration

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of First airborne transient EM survey in Antarctica: mapping of saline ground water system

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Temporal Changes in Spatial Distribution of Basal Melting and Freezing in the Catchment Areas of Whillans Ice Stream and Ice Stream C, West Antarctica: Interplay of Climatic Changes and Ice Dynamics

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Numerical modelling of granular subglacial deformation using the discrete element method

ABSTRACT We apply the Discrete Element Method (DEM) to explore the highly nonlinear dynamics of a... more ABSTRACT We apply the Discrete Element Method (DEM) to explore the highly nonlinear dynamics of a granular bed when exposed to stress conditions comparable to warm-based subglacial environments. As a method of validation of the simulated macromechanical behavior, and as a calibration benchmark, we compare results from successive laboratory ring-shear experiments on simple granular materials to results from similar numerical experiments. Overall, there is good agreement between the geotechnical behavior of the materials in the analogue and numerical experiments, and materials deform by an elasto-plastic rheology under the applied effective normal stress and shear velocity. By using the numerical approach it is possible to make a detailed analysis of the material dynamics and shear zone development during progressive shear strain. By visualizing the particles according to the sum of contact forces exerted onto them, the geometry of the heterogeneous stress network is visible in the form of force-carrying grain bridges and adjacent, volumetrically dominant, inactive zones. We demonstrate how the shear zone thickness and dilation is dependent on the effective deviatoric normal stress, where higher stresses mobilize material to greater depths. The data-parallel nature of the basic DEM formulation makes the problem ideal for utilizing the high arithmetic potential of modern general-purpose GPU's. Using the Nvidia Cuda C toolkit, the algorithm is formulated for spherical particles in three dimensions with a linear-elastic soft-body contact model.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Sedimentology of mega-scale glacial lineations on the Dubawnt Lake Palaeo-Ice Stream bed, Canada and implications for lineation genesis

Bookmarks Related papers MentionsView impact

Research paper thumbnail of California's Snow Gun and its implications for mass balance predictions under greenhouse warming

Precipitation has received limited treatment in glacier and snowpack mass balance models, largely... more Precipitation has received limited treatment in glacier and snowpack mass balance models, largely due to the poor resolution and confidence of precipitation predictions relative to temperature predictions derived from atmospheric models. Most snow and glacier mass balance models rely on statistical or lapse rate-based downscaling of general or regional circulation models (GCM's and RCM's), essentially decoupling sub-grid scale, orographically-driven evolution

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Survey of flow, topography and ablation on NW-Mýrdalsjökull, S-Iceland

Bookmarks Related papers MentionsView impact

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