Ice thickness and basal conditions of vestfonna ice cap, eastern svalbard
Ice thickness and basal conditions of vestfonna ice cap, eastern svalbard
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DOI：
10.1111/j.1468-0459.2011.00438.x
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发表时间：
2011-12
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通讯作者：
R. Pettersson;P. Christoffersen;J. Dowdeswell;V. Pohjola;A. Hubbard;T. Strozzi
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作者：
R. Pettersson;P. Christoffersen;J. Dowdeswell;V. Pohjola;A. Hubbard;T. Strozzi
彼得森，R.，Christoffersen，P.，Dowdeswell，J.A.，Pohjola，V.，Hubbard，A.和Strozzi，T.，2011。东斯瓦尔巴群岛维斯特凡纳冰帽的冰厚度和基本条件。地质学年鉴：系列A，自然地理学，93,311-322。摘要我们将2008年至2009年收集的地面脉冲雷达数据与1983年和1986年在斯瓦尔巴特群岛维斯特凡纳冰盖上获得的机载无线电回波探测数据结合在一起。机载数据集主要覆盖快速流动的出口冰川和边缘地带，而地面数据明确涵盖冰帽内部。因此，这里提供的数据是对海床地形和冰层厚度的第一次完整估计。冰下景观在海拔160米到+410米的−之间起伏起伏。平均冰层厚度为186m，冰总面积为2402 km2，冰体积为442±0.6 km3。这比目前用于估计区域与全球冰川体积的经验体积-面积比例关系得出的体积要小得多。这种差异可能取决于Vestfonna的当地条件，并强调在推导体积-面积比例参数时需要包括更多的体积观测。我们还推导出基础反射率作为床层热状况的替代指标。基本反射率值表明，快速流动的出口冰川受到温带条件的影响。Vestfonna的几何边界和基本条件将是发展冰盖数值模型和估计更准确的面积-体积比例参数的关键补充。
Pettersson, R., Christoffersen, P., Dowdeswell, J.A., Pohjola, V., Hubbard, A. and Strozzi, T., 2011. Ice thickness and basal conditions of Vestfonna Ice Cap, Eastern Svalbard. Geografiska Annaler: Series A, Physical Geography, 93, 311–322. DOI: 10.1111/j.1468‐0459.2011.00438.x Abstract We combined ground‐based pulsed radar data collected in 2008–2009 with airborne radio‐echo sounding data acquired in 1983 and 1986 over Vestfonna ice cap, Svalbard. The airborne dataset mainly covers the fast‐flowing outlet glaciers and the marginal zone, while the ground‐based data explicitly cover the interior part of the ice cap. The data presented here are thus the first complete estimate of bed topography and ice thickness. The subglacial landscape undulates with elevations between −160 and +410 m above sea level. The mean ice thickness is 186 m and the total ice area and volume are 2402 km2 and 442 ± 0.6 km3, respectively. This is a much smaller volume than those derived from empirical volume‐area scaling relationships currently used to estimate regional‐to‐global glacier volumes. This difference may depend on local conditions for Vestfonna and emphasizes the need to include more volume observations in the derivations of volume‐area scaling parameters. We also derive basal reflectivity as a proxy for thermal conditions at the bed. Basal reflectivity values suggest that fast‐flowing outlet glaciers are underlain by temperate conditions. The geometric boundaries and basal conditions for Vestfonna will be critical additions to the development of numerical models of the ice cap and to the estimation of more accurate area‐volume scaling parameters.