A multiple-step deformation history of basal ice from the Dye 3 (Greenland) core: new insights from the CO2 and CH4 content
Autor: | Reginald Lorrain, Véronique Verbeke, Sigfus J Johnsen, Jean-Louis Tison |
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Rok vydání: | 2002 |
Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Ice stream Pressure ridge Deformation (meteorology) 010502 geochemistry & geophysics 01 natural sciences Methane Core (optical fiber) chemistry.chemical_compound chemistry Carbon dioxide Ice sheet Petrology Geomorphology Geology Dye 3 0105 earth and related environmental sciences Earth-Surface Processes |
Zdroj: | Annals of Glaciology. 35:231-236 |
ISSN: | 1727-5644 0260-3055 |
Popis: | The ice depth–age relationship used for the Dye 3 (Greenland) core implies strong deformation of the silty ice present at the bottom. This paper focuses on the study of the relationship between carbon dioxide and methane concentration in the silty ice. In a CO2– CH4 diagram, sample points are well aligned along different straight lines with striking differences in slopes and concentration ranges, depending on their spatial location in the core. These slopes are interpreted as resulting from distinct mixing events between ice-sheet ice flowing from upstream and ice of local origin. Occurrence of these various mixing events suggests a complex deformation history for the basal part of the ice sheet. It involves a progressive build-up of the high-deformation layer along the basal flowline up-glacier from Dye 3, reaching 425 mthickness at the site. |
Databáze: | OpenAIRE |
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