The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation
Ice-shelf forced vibration modelling is performed using a full 3-D finite-difference elastic model, which also takes into account sub-ice seawater flow. The ocean flow in the cavity is described by the wave equation; therefore, ice-shelf flexures result from hydrostatic pressure perturbations in sub...
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ftcopernicus:oai:publications.copernicus.org:esdd31919 2023-05-15T16:41:46+02:00 The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation Konovalov, Y. V. 2018-09-26 application/pdf https://doi.org/10.5194/esdd-6-1605-2015 https://esd.copernicus.org/preprints/esd-2015-53/ eng eng doi:10.5194/esdd-6-1605-2015 https://esd.copernicus.org/preprints/esd-2015-53/ eISSN: 2190-4987 Text 2018 ftcopernicus https://doi.org/10.5194/esdd-6-1605-2015 2020-07-20T16:24:29Z Ice-shelf forced vibration modelling is performed using a full 3-D finite-difference elastic model, which also takes into account sub-ice seawater flow. The ocean flow in the cavity is described by the wave equation; therefore, ice-shelf flexures result from hydrostatic pressure perturbations in sub-ice seawater layer. Numerical experiments have been carried out for idealized rectangular and trapezoidal ice-shelf geometries. The ice-plate vibrations are modelled for harmonic ingoing pressure perturbations and for high-frequency spectra of the ocean swells. The spectra show distinct resonance peaks, which demonstrate the ability to model a resonant-like motion in the suitable conditions of forcing. The spectra and ice-shelf deformations obtained by the developed full 3-D model are compared with the spectra and the deformations modelled by the thin-plate Holdsworth and Glynn model (1978). The main resonance peaks and ice-shelf deformations in the corresponding modes, derived by the full 3-D model, are in agreement with the peaks and deformations obtained by the Holdsworth and Glynn model. The relative deviation between the eigenvalues (periodicities) in the two compared models is about 10 %. In addition, the full model allows observation of 3-D effects, for instance, the vertical distribution of the stress components in the plate. In particular, the full model reveals an increase in shear stress, which is neglected in the thin-plate approximation, from the terminus towards the grounding zone with a maximum at the grounding line in the case of the considered high-frequency forcing. Thus, the high-frequency forcing can reinforce the tidal impact on the ice-shelf grounding zone causing an ice fracture therein. Text Ice Shelf Copernicus Publications: E-Journals Holdsworth ENVELOPE(166.583,166.583,-72.133,-72.133) |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Ice-shelf forced vibration modelling is performed using a full 3-D finite-difference elastic model, which also takes into account sub-ice seawater flow. The ocean flow in the cavity is described by the wave equation; therefore, ice-shelf flexures result from hydrostatic pressure perturbations in sub-ice seawater layer. Numerical experiments have been carried out for idealized rectangular and trapezoidal ice-shelf geometries. The ice-plate vibrations are modelled for harmonic ingoing pressure perturbations and for high-frequency spectra of the ocean swells. The spectra show distinct resonance peaks, which demonstrate the ability to model a resonant-like motion in the suitable conditions of forcing. The spectra and ice-shelf deformations obtained by the developed full 3-D model are compared with the spectra and the deformations modelled by the thin-plate Holdsworth and Glynn model (1978). The main resonance peaks and ice-shelf deformations in the corresponding modes, derived by the full 3-D model, are in agreement with the peaks and deformations obtained by the Holdsworth and Glynn model. The relative deviation between the eigenvalues (periodicities) in the two compared models is about 10 %. In addition, the full model allows observation of 3-D effects, for instance, the vertical distribution of the stress components in the plate. In particular, the full model reveals an increase in shear stress, which is neglected in the thin-plate approximation, from the terminus towards the grounding zone with a maximum at the grounding line in the case of the considered high-frequency forcing. Thus, the high-frequency forcing can reinforce the tidal impact on the ice-shelf grounding zone causing an ice fracture therein. |
format |
Text |
author |
Konovalov, Y. V. |
spellingShingle |
Konovalov, Y. V. The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation |
author_facet |
Konovalov, Y. V. |
author_sort |
Konovalov, Y. V. |
title |
The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation |
title_short |
The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation |
title_full |
The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation |
title_fullStr |
The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation |
title_full_unstemmed |
The eigenvalue problem for ice-shelf vibrations: comparison of a full 3-D model with the thin plate approximation |
title_sort |
eigenvalue problem for ice-shelf vibrations: comparison of a full 3-d model with the thin plate approximation |
publishDate |
2018 |
url |
https://doi.org/10.5194/esdd-6-1605-2015 https://esd.copernicus.org/preprints/esd-2015-53/ |
long_lat |
ENVELOPE(166.583,166.583,-72.133,-72.133) |
geographic |
Holdsworth |
geographic_facet |
Holdsworth |
genre |
Ice Shelf |
genre_facet |
Ice Shelf |
op_source |
eISSN: 2190-4987 |
op_relation |
doi:10.5194/esdd-6-1605-2015 https://esd.copernicus.org/preprints/esd-2015-53/ |
op_doi |
https://doi.org/10.5194/esdd-6-1605-2015 |
_version_ |
1766032240296329216 |