Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf
Basal slip along glaciers and ice streams can be significantly modified by external time-dependent forcing, although it is not clear why some systems are more sensitive to tidal stresses. We have conducted a series of laboratory experiments to explore the effect of time varying load point velocity o...
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ftfrontimediafig:oai:figshare.com:article/19655019 2023-05-15T13:44:43+02:00 Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf Christine McCarthy Rob M. Skarbek Heather M. Savage 2022-04-26T04:29:00Z https://doi.org/10.3389/feart.2022.719074.s001 https://figshare.com/articles/figure/Image1_Tidal_Modulation_of_Ice_Streams_Effect_of_Periodic_Sliding_Velocity_on_Ice_Friction_and_Healing_pdf/19655019 unknown doi:10.3389/feart.2022.719074.s001 https://figshare.com/articles/figure/Image1_Tidal_Modulation_of_Ice_Streams_Effect_of_Periodic_Sliding_Velocity_on_Ice_Friction_and_Healing_pdf/19655019 CC BY 4.0 CC-BY Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change tidal modulation ice friction basal sliding stability healing Image Figure 2022 ftfrontimediafig https://doi.org/10.3389/feart.2022.719074.s001 2022-04-27T23:06:06Z Basal slip along glaciers and ice streams can be significantly modified by external time-dependent forcing, although it is not clear why some systems are more sensitive to tidal stresses. We have conducted a series of laboratory experiments to explore the effect of time varying load point velocity on ice-on-rock friction. Varying the load point velocity induces shear stress forcing, making this an analogous simulation of aspects of ice stream tidal modulation. Ambient pressure, double-direct shear experiments were conducted in a cryogenic servo-controlled biaxial deformation apparatus at temperatures between −2°C and −16°C. In addition to a background, median velocity (1 and 10 μm/s), a sinusoidal velocity was applied to the central sliding sample over a range of periods and amplitudes. Normal stress was held constant over each run (0.1, 0.5 or 1 MPa) and the shear stress was measured. Over the range of parameters studied, the full spectrum of slip behavior from creeping to slow-slip to stick-slip was observed, similar to the diversity of sliding styles observed in Antarctic and Greenland ice streams. Under conditions in which the amplitude of oscillation is equal to the median velocity, significant healing occurs as velocity approaches zero, causing a high-amplitude change in friction. The amplitude of the event increases with increasing period (i.e. hold time). At high normal stress, velocity oscillations force an otherwise stable system to behave unstably, with consistently-timed events during every cycle. Rate-state friction parameters determined from velocity steps show that the ice-rock interface is velocity strengthening. A companion paper describes a method of analyzing the oscillatory data directly. Forward modeling of a sinusoidally-driven slider block, using rate-and-state dependent friction formulation and experimentally derived parameters, successfully predicts the experimental output in all but a few cases. Still Image Antarc* Antarctic Greenland Frontiers: Figshare Antarctic Greenland |
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Open Polar |
collection |
Frontiers: Figshare |
op_collection_id |
ftfrontimediafig |
language |
unknown |
topic |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change tidal modulation ice friction basal sliding stability healing |
spellingShingle |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change tidal modulation ice friction basal sliding stability healing Christine McCarthy Rob M. Skarbek Heather M. Savage Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf |
topic_facet |
Solid Earth Sciences Climate Science Atmospheric Sciences not elsewhere classified Exploration Geochemistry Inorganic Geochemistry Isotope Geochemistry Organic Geochemistry Geochemistry not elsewhere classified Igneous and Metamorphic Petrology Ore Deposit Petrology Palaeontology (incl. Palynology) Structural Geology Tectonics Volcanology Geology not elsewhere classified Seismology and Seismic Exploration Glaciology Hydrogeology Natural Hazards Quaternary Environments Earth Sciences not elsewhere classified Evolutionary Impacts of Climate Change tidal modulation ice friction basal sliding stability healing |
description |
Basal slip along glaciers and ice streams can be significantly modified by external time-dependent forcing, although it is not clear why some systems are more sensitive to tidal stresses. We have conducted a series of laboratory experiments to explore the effect of time varying load point velocity on ice-on-rock friction. Varying the load point velocity induces shear stress forcing, making this an analogous simulation of aspects of ice stream tidal modulation. Ambient pressure, double-direct shear experiments were conducted in a cryogenic servo-controlled biaxial deformation apparatus at temperatures between −2°C and −16°C. In addition to a background, median velocity (1 and 10 μm/s), a sinusoidal velocity was applied to the central sliding sample over a range of periods and amplitudes. Normal stress was held constant over each run (0.1, 0.5 or 1 MPa) and the shear stress was measured. Over the range of parameters studied, the full spectrum of slip behavior from creeping to slow-slip to stick-slip was observed, similar to the diversity of sliding styles observed in Antarctic and Greenland ice streams. Under conditions in which the amplitude of oscillation is equal to the median velocity, significant healing occurs as velocity approaches zero, causing a high-amplitude change in friction. The amplitude of the event increases with increasing period (i.e. hold time). At high normal stress, velocity oscillations force an otherwise stable system to behave unstably, with consistently-timed events during every cycle. Rate-state friction parameters determined from velocity steps show that the ice-rock interface is velocity strengthening. A companion paper describes a method of analyzing the oscillatory data directly. Forward modeling of a sinusoidally-driven slider block, using rate-and-state dependent friction formulation and experimentally derived parameters, successfully predicts the experimental output in all but a few cases. |
format |
Still Image |
author |
Christine McCarthy Rob M. Skarbek Heather M. Savage |
author_facet |
Christine McCarthy Rob M. Skarbek Heather M. Savage |
author_sort |
Christine McCarthy |
title |
Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf |
title_short |
Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf |
title_full |
Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf |
title_fullStr |
Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf |
title_full_unstemmed |
Image1_Tidal Modulation of Ice Streams: Effect of Periodic Sliding Velocity on Ice Friction and Healing.pdf |
title_sort |
image1_tidal modulation of ice streams: effect of periodic sliding velocity on ice friction and healing.pdf |
publishDate |
2022 |
url |
https://doi.org/10.3389/feart.2022.719074.s001 https://figshare.com/articles/figure/Image1_Tidal_Modulation_of_Ice_Streams_Effect_of_Periodic_Sliding_Velocity_on_Ice_Friction_and_Healing_pdf/19655019 |
geographic |
Antarctic Greenland |
geographic_facet |
Antarctic Greenland |
genre |
Antarc* Antarctic Greenland |
genre_facet |
Antarc* Antarctic Greenland |
op_relation |
doi:10.3389/feart.2022.719074.s001 https://figshare.com/articles/figure/Image1_Tidal_Modulation_of_Ice_Streams_Effect_of_Periodic_Sliding_Velocity_on_Ice_Friction_and_Healing_pdf/19655019 |
op_rights |
CC BY 4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3389/feart.2022.719074.s001 |
_version_ |
1766205221228249088 |