Results 31 to 40 of about 832 (174)

Effects of basal topography and ice-sheet surface slope in a subglacial glaciofluvial deposition model

Journal of Glaciology, 2023
We use a mathematical model to investigate the effect of basal topography and ice surface slope on transport and deposition of sediment within a water-filled subglacial channel. In our model, three zones of different behaviour occur. In the zone furthest
David Stevens, Jeremy C. Ely, Stephen J. Livingstone, Chris D. Clark, Frances E. G. Butcher, Ian Hewitt   +5 more
doaj   +1 more source

Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures

Journal of Glaciology, 2018
Stable isotopes of water (δ18O and δ2H) were measured in the debris-laden ice underlying an Antarctic blue ice moraine, and in adjoining Law Glacier in the central Transantarctic Mountains.
JOSEPH A. GRALY, KATHY J. LICHT, CHRISTINE M. KASSAB, BROXTON W. BIRD, MICHAEL R. KAPLAN   +4 more
doaj   +1 more source

Viable cold-tolerant iron-reducing microorganisms in geographically diverse subglacial environments [PDF]

Biogeosciences, 2017
Subglacial environments are known to harbour metabolically diverse microbial communities. These microbial communities drive chemical weathering of underlying bedrock and influence the geochemistry of glacial meltwater.
S. L. Nixon, J. P. Telling, J. L. Wadham, C. S. Cockell   +3 more
doaj   +1 more source

ANTASed – An Updated Sediment Model for Antarctica

Frontiers in Earth Science, 2021
We compile existing seismic, gravity, radar and magnetic data, together with the subglacial bedrock relief from the BEDMACHINE project, to build the most detailed sediment model for Antarctica.
A. Baranov, A. Morelli, A. Chuvaev
doaj   +1 more source

A new percussion hammer mechanism for a borehole deployable subglacial sediment corer

Annals of Glaciology, 2021
Subglacial sediments have the potential to reveal information about the controls on glacier flow, changes in ice-sheet history and characterise life in those environments.
Keith Makinson, Daniel Ashurst, Paul G. D. Anker, James A. Smith, Dominic A. Hodgson, Peter E. D. Davis, Andrew M. Smith   +6 more
doaj   +1 more source

Subglacial sediment deformation in the Ross Sea, Antarctica

Quaternary Science Advances, 2021
Abstract:: The Ross Sea embayment is the outlet for one-third of all Antarctic ice flow, receiving input from both East and West Antarctica. Marine-based ice streams, whose stability is susceptible to global sea-level changes, expand and contract across the Ross Sea continental shelf, eroding and deforming the substrate and transporting sediment ...
Delaney E. Robinson, John Menzies, Julia S. Wellner, Rachel W. Clark   +3 more
openaire   +2 more sources

Subglacial sediment distribution from constrained seismic inversion, using MuLTI software: examples from Midtdalsbreen, Norway

Annals of Glaciology, 2019
Fast ice flow is associated with the deformation of subglacial sediment. Seismic shear velocities, Vs, increase with the rigidity of material and hence can be used to distinguish soft sediment from hard bedrock substrates.
Siobhan F. Killingbeck, Adam D. Booth, Philip W. Livermore, Landis J. West, Benedict T. I. Reinardy, Atle Nesje   +5 more
doaj   +1 more source

Advances in understanding subglacial meltwater drainage from past ice sheets

Annals of Glaciology, 2022
Meltwater drainage beneath ice sheets is a fundamental consideration for understanding ice–bed conditions and bed-modulated ice flow, with potential impacts on terminus behavior and ice-shelf mass balance.
Lauren M. Simkins, Sarah L. Greenwood, Monica C. M. Winsborrow, Lilja R. Bjarnadóttir, Allison P. Lepp   +4 more
doaj   +1 more source

Deformation ‘boundary front’ movements in subglacial tills—A microsedimentological perspective from till sequences near Pine Point, NWT, Canada

The Depositional Record, 2019
Investigations of glacial sediment exposures in a former open pit in the Pine Point Mining District, Northwest Territories, reveal evidence of changes in stress magnitude as exhibited by the movement of deformation ‘fronts’ within subglacial tills, as ...
John Menzies, Roger C. Paulen, Jessey M. Rice, M. Beth McClenaghan, Natasha M. Oviatt, Nitasha Dhillon   +5 more
doaj   +1 more source

The Periglacial Lake Bretjorna (Ledovoe), Western Svalbard: History of Formation and Recent Sedimentation

Лëд и снег, 2023
This paper presents the results of geomorphological, geochronological and lithological investigation of a young sedimentation basin – the periglacial Lake Bretjorna (Ledovoe).
N. I. Meshcheriakov, O. V. Kokin, I. S. Usyagina, N. E. Kasatkina   +3 more
doaj   +1 more source