Deep sea-floor evidence of past ice streams off the Antarctic Peninsula

Canals, Miquel; Úrgeles, Roger; Calafat, Antoni

doi:10.1130/0091-7613(2000)028<0031:dsfeop>2.3.co;2

Cited by 66 publications

(94 citation statements)

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“…These amplitudes are similar to those observed for well-preserved lineations on Antarctic shelves [Dowdeswell et al, 2004]. Streamlined subglacial bedforms, often referred to as 'mega-scale glacial lineations' [Clark, 1993[Clark, , 1994, have been used to infer the former presence of fast-flowing ice streams on continental shelves in both the Arctic and Antarctic [e.g., Shipp et al, 1999Shipp et al, , 2002Canals et al, 2000;Wellner et al, 2001;Ó Cofaigh et al, 2002;Ottesen et al, 2002Ottesen et al, , 2005.…”

Section: Discussionsupporting

confidence: 58%

Assemblages of submarine landforms produced by tidewater glaciers in Svalbard

2006

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[1] High-resolution swath bathymetry from the marine margins of several Svalbard tidewater glaciers shows an assemblage of submarine landforms that is probably linked to glacier surging. These landforms are essentially unmodified since their initial deposition over the past hundred years or so because they have not been subjected to subaerial erosion or periglacial activity. Swath images comprise an assemblage of superimposed landforms, allowing reconstruction of relative age of deposition: (1) large transverse ridges, interpreted as recessional moraines overridden by a subsequent ice advance; (2) a series of curvilinear streamlined bedforms orientated parallel to former ice flow, interpreted as lineations formed subglacially during rapid advance; (3) large terminal ridges, marking the farthest extent of ice at the last advance, with flow lobes immediately beyond interpreted as submarine debris flows; (4) a series of interconnected rhombohedral ridges, interpreted as a product of soft sediment squeezing into crevasses formed at the glacier bed, probably formed during immediate post-surge stagnation; and (5) a series of fairly evenly spaced small transverse ridges, interpreted as push moraines produced annually at tidewater glacier termini during retreat. A simple descriptive landsystem model for tidewater glaciers of probable surge type is derived from these observations. We also show that megascale glacial lineations can form not only beneath large ice streams, but are also produced beneath surging tidewater glaciers lying on deforming sedimentary beds.

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Section: Discussionsupporting

confidence: 58%

Assemblages of submarine landforms produced by tidewater glaciers in Svalbard

2006

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“…Shipp et al (1999) suggested that these features represent the rst marine discovery of Clark's (1993) mega-scale glacial lineations. Canals et al (2000) have also found submarine landforms analogous to mega-scale glacial lineations inferred to have been sculptured by a large ice stream which drained an expanded Antarctic Peninsula Ice Cap during the Last Glacial Maximum. These features are similar in scale and character to terrestrial mega-scale glacial lineations, but show uninterrupted continuity along their 100 km length.…”

Section: Evidence From the Margins Of Contemporary Ice Sheetsmentioning

confidence: 95%

“…These features are similar in scale and character to terrestrial mega-scale glacial lineations, but show uninterrupted continuity along their 100 km length. Canals et al (2000) refer to this sinuous track of grooves and ridges as a 'bundle structure' and suggest that it may be the largest iceow-related landform ever identi ed. These ndings considerably strengthen the hypothesis that attenuated drumlins and mega-scale glacial lineations are indicative of fast ice ow.…”

Section: Evidence From the Margins Of Contemporary Ice Sheetsmentioning

confidence: 99%

“…The discovery by Canals et al (2000) raises a number of interesting questions with regard to the actual processes that facilitated fast ice ow and produce the observed mega-scale glacial lineation of ridges and grooves. It could be argued that it is unlikely that point initiation in the down-ice direction could account for their exceptional length and sinuosity (up to 100 km) and linear initiation is unlikely (see arguments above).…”

Section: Evidence From the Margins Of Contemporary Ice Sheetsmentioning

confidence: 99%

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Are long subglacial bedforms indicative of fast ice flow?

Stokes¹,

Clark²

2002

Boreas

188

103

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“…Clark 1993;Stokes & Clark 2003;De Angelis & Kleman 2008), whilst the palaeoice stream beds offshore have been mapped from marine geophysical data, such as swath bathymetry and seismic data (e.g. Canals et al 2000;O Cofaighet al 2002;Ottesen et al 2005;Graham et al 2007).…”

mentioning

confidence: 99%

The last deglaciation of the Norwegian Channel – geomorphology, stratigraphy and radiocarbon dating

Morén

Sejrup

Hjelstuen

et al. 2017

Boreas

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Based on high‐resolution TOPAS acoustic data, bathymetric data sets and sediment cores from the Norwegian Channel, the last retreat of the Norwegian Channel Ice Stream has been investigated. Mapping of ice‐marginal features such as grounding‐zone wedges and terminal moraines off western Norway suggest that the retreat of the grounding line in this part of the channel was interrupted by frequent stillstands, whereas the channel south of the threshold at Jæren does not have crossing ice‐marginal landforms. Three main seismic units have been identified, and, based on their seismic characteristics, in addition to study of sediment cores, these units are interpreted as till (U1), glacial marine sediment (U2) and Holocene hemipelagic sediment (U3). Based on new and published radiocarbon dates of the lower part of U2, combined with dates from the adjacent areas, it is concluded that the grounding line started to retreat from the shelf edge at about 19 ka and that the inner part of Skagerrak was ice free at 17.6 ka. This gives an average retreat rate of 450 m a−1, which is generally higher than mean retreat rates estimated for other palaeo‐ice streams (15–310 m a−1).

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Deep sea-floor evidence of past ice streams off the Antarctic Peninsula

Cited by 66 publications

References 0 publications

Assemblages of submarine landforms produced by tidewater glaciers in Svalbard

Assemblages of submarine landforms produced by tidewater glaciers in Svalbard

Are long subglacial bedforms indicative of fast ice flow?

The last deglaciation of the Norwegian Channel – geomorphology, stratigraphy and radiocarbon dating

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