Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties
A preferred orientation of the anisotropic ice crystals influences the viscosity of the ice bulk and the dynamic behaviour of glaciers and ice sheets. Knowledge about the distribution of crystal anisotropy is mainly provided by crystal orientation fabric (COF) data from ice cores. However, the devel...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-02-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/9/367/2015/tc-9-367-2015.pdf |
| _version_ | 1811342473704767488 |
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| author | A. Diez O. Eisen |
| author_facet | A. Diez O. Eisen |
| author_sort | A. Diez |
| collection | DOAJ |
| description | A preferred orientation of the anisotropic ice crystals influences the
viscosity of the ice bulk and the dynamic behaviour of glaciers and ice
sheets. Knowledge about the distribution of crystal anisotropy is mainly
provided by crystal orientation fabric (COF) data from ice cores. However,
the developed anisotropic fabric influences not only the flow behaviour
of ice but also the propagation of seismic waves. Two effects are important:
(i) sudden changes in COF lead to englacial reflections, and (ii) the
anisotropic fabric induces an angle dependency on the seismic velocities and,
thus, recorded travel times. A framework is presented here to connect COF data
from ice cores with the elasticity tensor to determine seismic velocities and
reflection coefficients for cone and girdle fabrics. We connect the
microscopic anisotropy of the crystals with the macroscopic anisotropy of the
ice mass, observable with seismic methods. Elasticity tensors for different
fabrics are calculated and used to investigate the influence of the
anisotropic ice fabric on seismic velocities and reflection coefficients,
englacially as well as for the ice–bed contact. Hence, it is possible to
remotely determine the bulk ice anisotropy. |
| first_indexed | 2024-04-13T19:11:40Z |
| format | Article |
| id | doaj.art-c0a767478d334527997f8e91c0991bd3 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-04-13T19:11:40Z |
| publishDate | 2015-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-c0a767478d334527997f8e91c0991bd32022-12-22T02:33:48ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242015-02-019136738410.5194/tc-9-367-2015Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core propertiesA. Diez0O. Eisen1Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyA preferred orientation of the anisotropic ice crystals influences the viscosity of the ice bulk and the dynamic behaviour of glaciers and ice sheets. Knowledge about the distribution of crystal anisotropy is mainly provided by crystal orientation fabric (COF) data from ice cores. However, the developed anisotropic fabric influences not only the flow behaviour of ice but also the propagation of seismic waves. Two effects are important: (i) sudden changes in COF lead to englacial reflections, and (ii) the anisotropic fabric induces an angle dependency on the seismic velocities and, thus, recorded travel times. A framework is presented here to connect COF data from ice cores with the elasticity tensor to determine seismic velocities and reflection coefficients for cone and girdle fabrics. We connect the microscopic anisotropy of the crystals with the macroscopic anisotropy of the ice mass, observable with seismic methods. Elasticity tensors for different fabrics are calculated and used to investigate the influence of the anisotropic ice fabric on seismic velocities and reflection coefficients, englacially as well as for the ice–bed contact. Hence, it is possible to remotely determine the bulk ice anisotropy.http://www.the-cryosphere.net/9/367/2015/tc-9-367-2015.pdf |
| spellingShingle | A. Diez O. Eisen Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties The Cryosphere |
| title | Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties |
| title_full | Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties |
| title_fullStr | Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties |
| title_full_unstemmed | Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties |
| title_short | Seismic wave propagation in anisotropic ice – Part 1: Elasticity tensor and derived quantities from ice-core properties |
| title_sort | seismic wave propagation in anisotropic ice part 1 elasticity tensor and derived quantities from ice core properties |
| url | http://www.the-cryosphere.net/9/367/2015/tc-9-367-2015.pdf |
| work_keys_str_mv | AT adiez seismicwavepropagationinanisotropicicepart1elasticitytensorandderivedquantitiesfromicecoreproperties AT oeisen seismicwavepropagationinanisotropicicepart1elasticitytensorandderivedquantitiesfromicecoreproperties |