Summary This paper reports the results of a field survey carried out on an ice-wedge polygon site in the Terra Nova Bay area, in northern Victoria Land. Ice wedges were found at depths ranging from 27 cm to 55 cm from the ground surface. The ice wedges had a width at their top of 13 to 55 cm, and a...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.529.3432 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea204.pdf |
| Summary: | Summary This paper reports the results of a field survey carried out on an ice-wedge polygon site in the Terra Nova Bay area, in northern Victoria Land. Ice wedges were found at depths ranging from 27 cm to 55 cm from the ground surface. The ice wedges had a width at their top of 13 to 55 cm, and a height varying from 50 cm to over 80 cm. Petrofabric analyses were also performed on ice-wedge ice to investigate changes in fabric across wedges, in relation to the growth mechanism. Crystal size increased from the centre outward; c-axis directions showed a preferred vertical to sub-vertical orientation, parallel to the axial plane at the wedge centre, and parallel to the foliation at the boundaries of the wedges. A co-isotopic study was performed by measuring both the oxygen (δ18O) and hydrogen (δD) isotope compositions and the tritium activity. The measurements obtained for δ18O and δD had extremely negative d excess values, showing a strong divergence from the snowfalls expected to occur at the elevation of the site (874 m a.s.l.). Sublimation processes were taken into account to define the origin of the ice-wedge ice. A data logger, using NTC sensors, was installed to record hourly temperatures of the air, of the ground surface, and of the top and bottom of an ice wedge. A complete year of monitoring of the ice-wedge thermal regime (1 February 2004 – 31 January 2005) |
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