Detection of superimposed ice on the glaciers Kongsvegen and midre Love´nbreen, Svalbard, using SAR satellite imagery
Authors: König, Max; Wadham, Jemma; Winther, Jan-Gunnar; Kohler, Jack; Nuttall, Anne-Marie
Source: Annals of Glaciology, Volume 34, Number 1, 1 January 2002 , pp. 335-342(8)
Publisher: International Glaciological Society
Abstract:Superimposed ice forms when meltwater refreezes onto a sub-freezing glacier surface. The accumulation zones of many Arctic glaciers include large areas of superimposed ice, which for mass-balance purposes have to be distinguished from the ablation zone consisting of glacier ice. We examine the ability of synthetic aperture radar (SAR) satellite sensors to detect superimposed ice on the glaciers Kongsvegen and midre Lovénbreen on Svalbard. Structural analysis of ice cores as well as surface observations from these glaciers in 1999 and 2000 provide a spatial record of superimposed ice. Winter SAR images show three distinct zones, which correspond closely to areas of glacier ice, superimposed ice and firn. This is seen very clearly on Kongsvegen, but not as clearly on the much smaller midre Lovénbreen. One possible explanation for the contrasting SAR signal may relate to the differing air-bubble content of firn, superimposed ice and glacier ice. Thin layers of winter-formed superimposed ice (<10 cm) in some places are not seen on the SAR images, indicating that a certain thickness is needed for detection. The equilibrium-line altitude cannot be detected since the SAR cannot differentiate old superimposed ice, superimposed ice formed currently in the accumulation area in summer and superimposed ice formed currently in the ablation zone in autumn and winter.
Document Type: Research article
Publication date: 2002-01-01
- The Annals of Glaciology is a peer-reviewed, thematic journal published 2 to 4 times a year by the International Glaciological Society (IGS). Publication frequency is determined and volume/issue numbers assigned by the IGS Council on a year-to-year basis and with a lead time of 3 to 4 years. The Annals of Glaciology is included in the ISI Science Citation Index from volume 50, number 50 onwards.
Themes can be on any aspect of the study of snow and ice. Individual members can make a suggestion for a theme for an Annals issue to the Secretary General, who will forward it to the IGS Publications Committee. The IGS Publication Committee will make a recommendation for an individual themed Annals issue, together with a potential Annals Chief Editor for that issue, to IGS Council. The IGS Council will make the decision whether to proceed, taking into account the spread of topics and the overall capacity for publication of pages in Annals.
- Editorial Board
- Information for Authors
- ingentaconnect is not responsible for the content or availability of external websites