The burial of ice in the proglacial environment on Bylot Island, Arctic Canada

Timing of advance and basal condition of the Laurentide Ice Sheet during the last glacial maximum in the Richardson Mountains, NWT

“…The balls of hair could have been deposited on the surface of the aufeis by a small animal prior to its burial. The preservation of aufeis in relict permafrost is not unique to this area and has been described previously by Moorman and Michel (2000) in a proglacial setting on Bylot Island, NU, and by Froese et al (2006) for the Klondike goldfields of west-central Yukon Territory. The interpretation that the massive ice unit consists of a buried aufeis also allows us to explain the presence of carbonate concretions released upon melting of the ice.…”

Timing of advance and basal condition of the Laurentide Ice Sheet during the last glacial maximum in the Richardson Mountains, NWT

“…The balls of hair could have been deposited on the surface of the aufeis by a small animal prior to its burial. The preservation of aufeis in relict permafrost is not unique to this area and has been described previously by Moorman and Michel (2000) in a proglacial setting on Bylot Island, NU, and by Froese et al (2006) for the Klondike goldfields of west-central Yukon Territory. The interpretation that the massive ice unit consists of a buried aufeis also allows us to explain the presence of carbonate concretions released upon melting of the ice.…”

Origin, burial and preservation of late Pleistocene-age glacier ice in Arctic permafrost (Bylot Island, NU, Canada)

“…Patterns of preferred crystal orientation combined with the occurrence of deformation features in the form of debris bands suggest that the ice has been subjected to long-continued shear stress caused by the motion of a glacier (Benn and Evans, 2010;Lawson, 1979). The debris bands cross-cutting the buried glacier ice are comparable to those observed in the terminus zone of Stagnation Glacier on Bylot Island, where basal sediments were transported to the glacier surface through shear planes (Moorman and Michel, 2000).…”

Ground-penetrating radar measurements of debris thickness on Lirung Glacier, Nepal

“…This indicates that the ice surface can be reliably interpreted as distinct from processing artefacts or multiples of the debris surface and that GPR can realistically be used to measure debris thickness accurately at least in the range 0.16–0.58 m (cf. Moorman and Michel, 2000; Moorman and others, 2003; Bradford and others, 2005; Gusmeroli and others, 2015). The spread of data around the 1:1 line likely represents a combination of picking imprecision and spatio-temporal wave speed variability, and outliers on linear regression are assumed to be mispicks of the ice surface, where the reflections picked are artefacts of processing or the physical expression of some other subsurface feature, for example an off-nadir reflector.…”

“…This shows that GPR can be used to image the ice surface through a debris layer, even at shallow depths of <1 m (cf. Lønne and Lauritsen, 1996; Moorman and Michel, 2000; Wu and Liu, 2012). Measurable debris thickness ranges reported in Table 2 and Figure 6 indicate that choice of operating frequency is crucial to this end.…”

Timing of advance and basal condition of the Laurentide Ice Sheet during the last glacial maximum in the Richardson Mountains, NWT

“…The balls of hair could have been deposited on the surface of the aufeis by a small animal prior to its burial. The preservation of aufeis in relict permafrost is not unique to this area and has been described previously by Moorman and Michel (2000) in a proglacial setting on Bylot Island, NU, and by Froese et al (2006) for the Klondike goldfields of west-central Yukon Territory. The interpretation that the massive ice unit consists of a buried aufeis also allows us to explain the presence of carbonate concretions released upon melting of the ice.…”

Origin, burial and preservation of late Pleistocene-age glacier ice in Arctic permafrost (Bylot Island, NU, Canada)

“…Patterns of preferred crystal orientation combined with the occurrence of deformation features in the form of debris bands suggest that the ice has been subjected to long-continued shear stress caused by the motion of a glacier (Benn and Evans, 2010;Lawson, 1979). The debris bands cross-cutting the buried glacier ice are comparable to those observed in the terminus zone of Stagnation Glacier on Bylot Island, where basal sediments were transported to the glacier surface through shear planes (Moorman and Michel, 2000).…”

Ground-penetrating radar measurements of debris thickness on Lirung Glacier, Nepal

“…This indicates that the ice surface can be reliably interpreted as distinct from processing artefacts or multiples of the debris surface and that GPR can realistically be used to measure debris thickness accurately at least in the range 0.16–0.58 m (cf. Moorman and Michel, 2000; Moorman and others, 2003; Bradford and others, 2005; Gusmeroli and others, 2015). The spread of data around the 1:1 line likely represents a combination of picking imprecision and spatio-temporal wave speed variability, and outliers on linear regression are assumed to be mispicks of the ice surface, where the reflections picked are artefacts of processing or the physical expression of some other subsurface feature, for example an off-nadir reflector.…”

“…This shows that GPR can be used to image the ice surface through a debris layer, even at shallow depths of <1 m (cf. Lønne and Lauritsen, 1996; Moorman and Michel, 2000; Wu and Liu, 2012). Measurable debris thickness ranges reported in Table 2 and Figure 6 indicate that choice of operating frequency is crucial to this end.…”

Timing of advance and basal condition of the Laurentide Ice Sheet during the last glacial maximum in the Richardson Mountains, NWT

“…The balls of hair could have been deposited on the surface of the aufeis by a small animal prior to its burial. The preservation of aufeis in relict permafrost is not unique to this area and has been described previously by Moorman and Michel (2000) in a proglacial setting on Bylot Island, NU, and by Froese et al (2006) for the Klondike goldfields of west-central Yukon Territory. The interpretation that the massive ice unit consists of a buried aufeis also allows us to explain the presence of carbonate concretions released upon melting of the ice.…”

Origin, burial and preservation of late Pleistocene-age glacier ice in Arctic permafrost (Bylot Island, NU, Canada)

“…Patterns of preferred crystal orientation combined with the occurrence of deformation features in the form of debris bands suggest that the ice has been subjected to long-continued shear stress caused by the motion of a glacier (Benn and Evans, 2010;Lawson, 1979). The debris bands cross-cutting the buried glacier ice are comparable to those observed in the terminus zone of Stagnation Glacier on Bylot Island, where basal sediments were transported to the glacier surface through shear planes (Moorman and Michel, 2000).…”

Ground-penetrating radar measurements of debris thickness on Lirung Glacier, Nepal

“…This indicates that the ice surface can be reliably interpreted as distinct from processing artefacts or multiples of the debris surface and that GPR can realistically be used to measure debris thickness accurately at least in the range 0.16–0.58 m (cf. Moorman and Michel, 2000; Moorman and others, 2003; Bradford and others, 2005; Gusmeroli and others, 2015). The spread of data around the 1:1 line likely represents a combination of picking imprecision and spatio-temporal wave speed variability, and outliers on linear regression are assumed to be mispicks of the ice surface, where the reflections picked are artefacts of processing or the physical expression of some other subsurface feature, for example an off-nadir reflector.…”

“…This shows that GPR can be used to image the ice surface through a debris layer, even at shallow depths of <1 m (cf. Lønne and Lauritsen, 1996; Moorman and Michel, 2000; Wu and Liu, 2012). Measurable debris thickness ranges reported in Table 2 and Figure 6 indicate that choice of operating frequency is crucial to this end.…”