Ice-sheet dynamics and ice streaming along the coastal parts of northern Norway

Ottesen, Dag; Stokes, Chris R.; Rise, Leif; Olsen, Lars

doi:10.1016/j.quascirev.2008.01.014

Cited by 113 publications

(98 citation statements)

References 78 publications

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“…Importantly, these and other data have been used to develop a model of bedform variability under Antarctic palaeoice streams (Wellner et al, 2001), whereby small features eroded into bedrock progressively evolve downflow into more elongate sedimentary bedforms. In this model, and in similar studies of ice stream landsystems (Wellner et al, 2001(Wellner et al, , 2006Mosola and Anderson, 2006;Bradwell et al, 2008;Ottesen et al, 2008), changes in subglacial lithology were proposed as the main control on ice dynamics, and hence on the along-flow geomorphic progression. However despite conceptual advances associated with such models, the majority of Antarctic studies used only limited swath bathymetric coverage and often simplified observations as single 'snapshots' in time, impeding more detailed geomorphic interpretations of entire palaeo-ice stream systems.…”

Section: Introductionmentioning

confidence: 92%

“…2 and 5). We divide their description here into: (i) the inner shelf; (ii) the mid-shelf, where tributary troughs converge; and (iii) the middle and outer shelf north of 73 30 0 S. All features are interpreted as subglacial or ice marginal (after Ottesen et al, 2008), and adhere to the criteria defined in Table 2.…”

Section: Geomorphology: Description and Interpretation Of Bedformsmentioning

confidence: 99%

“…S3). The features possess morphological traits of grounding zone wedges (GZWs), including steep downstream-facing ramps, shallow back-slopes, and lineations terminating at wedge crests (Alley et al, 1989;Vanneste and Larter, 1995;Howat and Domack, 2003;Ó Cofaigh et al, 2005b;Evans et al, 2005aEvans et al, , 2006Anandakrishnan et al, 2007;Ottesen et al, 2008). The GZW crests rise up to 100-120 m above the surrounding sea floor, are 4 km wide, and extend over 5-10 km.…”

Section: Inner To Middle Shelfmentioning

confidence: 99%

“…basal drag/flow mechanics), ice dynamics, and bedforms is therefore required. Exposed palaeo-ice stream beds provide an opportunity to improve our understanding of complex bed controls on ice flow King et al, 2007;Ottesen et al, 2008;) by investigating sediment and bedform signatures over wide areas and over varying substrates.…”

Section: Introductionmentioning

confidence: 99%

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Bedform signature of a West Antarctic palaeo-ice stream reveals a multi-temporal record of flow and substrate control

Graham

Larter

Gohl

et al. 2009

Quaternary Science Reviews

174

173

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a b s t r a c tThe presence of a complex bedform arrangement on the sea floor of the continental shelf in the western Amundsen Sea Embayment, West Antarctica, indicates a multi-temporal record of flow related to the activity of one or more ice streams in the past. Mapping and division of the bedforms into distinct landform assemblages reveals their time-transgressive history, which implies that bedforms can neither be considered part of a single downflow continuum nor a direct proxy for palaeo-ice velocity, as suggested previously. A main control on the bedform imprint is the geology of the shelf, which is divided broadly between rough bedrock on the inner shelf, and smooth, dipping sedimentary strata on the middle to outer shelf. Inner shelf bedform variability is well preserved, revealing information about local, complex basal ice conditions, meltwater flow, and ice dynamics over time. These details, which are not apparent at the scale of regional morphological studies, indicate that past ice streams flowed across the entire shelf at times, and often had onset zones that lay within the interior of the Antarctic Ice Sheet today. In contrast, highly elongated subglacial bedforms on sedimentary strata of the middle to outer shelf represent a timeslice snapshot of the last activity of ice stream flow, and may be a truer representation of fast palaeo-ice flow in these locations. A revised model for ice streams on the shelf captures complicated multi-temporal bedform patterns associated with an Antarctic palaeo-ice stream for the first time, and confirms a strong substrate control on a major ice stream system that drained the West Antarctic Ice Sheet during the Late Quaternary.

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Section: Introductionmentioning

confidence: 92%

Section: Geomorphology: Description and Interpretation Of Bedformsmentioning

confidence: 99%

Section: Inner To Middle Shelfmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Bedform signature of a West Antarctic palaeo-ice stream reveals a multi-temporal record of flow and substrate control

Graham

Larter

Gohl

et al. 2009

Quaternary Science Reviews

174

173

View full text Add to dashboard Cite

show abstract

“…Ottesen et al, 2008). This cross-shelf trough exhibits many of the geomorphological criteria for identifying palaeoice streams (Stokes and Clark, 1999), including a convergent onset zone feeding into a main trunk characterised by mega-scale glacial lineations with abrupt lateral margins and ice stream shear margin moraines (black arrows); (b) Seismic data across the grounding zone wedge (100 m s = ~90 m on the vertical axis).…”

Section: Figurementioning

confidence: 99%