Two-way traveltimes of internal layers and ice thickness between Dome C - Vostok - Dome A
Fuente:
PANGAEA
Enregistré dans:
| Auteurs principaux: | , , , , , , , , |
|---|---|
| Format: | Dataset Open Access |
| Langue: | en |
| Publié: |
PANGAEA
2014
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1867171367677329408 |
|---|---|
| author | Sun, Bo Moore, John C Zwinger, Thomas Zhao, Liyun Steinhage, Daniel Tang, Xueyuan Zhang, Dong Cui, Xiangbin Martín, Carlos |
| author_facet | Sun, Bo Moore, John C Zwinger, Thomas Zhao, Liyun Steinhage, Daniel Tang, Xueyuan Zhang, Dong Cui, Xiangbin Martín, Carlos |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Chinese scientists will start to drill a deep ice core at Kunlun station near Dome A in the near future. Recent work has predicted that Dome A is a location where ice older than 1 million years can be found. We model flow, temperature and the age of the ice by applying a three-dimensional, thermomechanically coupled full-Stokes model to a 70 × 70 km**2 domain around Kunlun station, using isotropic non-linear rheology and different prescribed anisotropic ice fabrics that vary the evolution from isotropic to single maximum at 1/3 or 2/3 depths. The variation in fabric is about as important as the uncertainties in geothermal heat flux in determining the vertical advection which in consequence controls both the basal temperature and the age profile. We find strongly variable basal ages across the domain since the ice varies greatly in thickness, and any basal melting effectively removes very old ice in the deepest parts of the subglacial valleys. Comparison with dated radar isochrones in the upper one third of the ice sheet cannot sufficiently constrain the age of the deeper ice, with uncertainties as large as 500 000 years in the basal age. We also assess basal age and thermal state sensitivities to geothermal heat flux and surface conditions. Despite expectations of modest changes in surface height over a glacial cycle at Dome A, even small variations in the evolution of surface conditions cause large variation in basal conditions, which is consistent with basal accretion features seen in radar surveys. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_836120 |
| institution | PANGAEA |
| language | en |
| publishDate | 2014 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Two-way traveltimes of internal layers and ice thickness between Dome C - Vostok - Dome A Sun, Bo Moore, John C Zwinger, Thomas Zhao, Liyun Steinhage, Daniel Tang, Xueyuan Zhang, Dong Cui, Xiangbin Martín, Carlos AWI_Glac; Glaciology @ AWI Chinese scientists will start to drill a deep ice core at Kunlun station near Dome A in the near future. Recent work has predicted that Dome A is a location where ice older than 1 million years can be found. We model flow, temperature and the age of the ice by applying a three-dimensional, thermomechanically coupled full-Stokes model to a 70 × 70 km**2 domain around Kunlun station, using isotropic non-linear rheology and different prescribed anisotropic ice fabrics that vary the evolution from isotropic to single maximum at 1/3 or 2/3 depths. The variation in fabric is about as important as the uncertainties in geothermal heat flux in determining the vertical advection which in consequence controls both the basal temperature and the age profile. We find strongly variable basal ages across the domain since the ice varies greatly in thickness, and any basal melting effectively removes very old ice in the deepest parts of the subglacial valleys. Comparison with dated radar isochrones in the upper one third of the ice sheet cannot sufficiently constrain the age of the deeper ice, with uncertainties as large as 500 000 years in the basal age. We also assess basal age and thermal state sensitivities to geothermal heat flux and surface conditions. Despite expectations of modest changes in surface height over a glacial cycle at Dome A, even small variations in the evolution of surface conditions cause large variation in basal conditions, which is consistent with basal accretion features seen in radar surveys. |
| title | Two-way traveltimes of internal layers and ice thickness between Dome C - Vostok - Dome A |
| topic | AWI_Glac; Glaciology @ AWI |
| url | https://doi.org/10.1594/PANGAEA.836120 |