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Author (down)
Title Observation of low shear wave velocity at the base of the polar ice sheets: evidence for enhanced anisotropy Type Journal Article
Year 2012 Publication Geophysical Journal International Abbreviated Journal
Volume 190 Issue 1 Pages 391 -405
Keywords
Abstract We analyse seismic data from the broad-band stations located on the Antarctic and Greenland ice sheets to determine the large-scale seismic parameters of the polar ice sheets. The P-to-S converted waves at the ice/rock interface and inside the ice sheets and their multiples (the P receiver functions) are used to estimate the in situ P velocity Vp and the P-to-S velocity ratio Vp/Vs of the polar ice. The thickness of the whole ice layer is precisely known either from radio echo soundings or from ice core drillings allowing thus an accurate determination of Vp and Vp/Vs. At some places in and near the Wilkes Basin, a sedimentary layer is probably squeezed between the ice and the bedrock. We find that the polar ice caps have a two-layer structure, the upper layer of variable thickness about 2/3 of the total thickness with velocities very close to the ice standard values and the lower layer preserving a standard Vp but with about 25 per cent smaller shear wave velocity and a more or less constant thickness. The shear-velocity drop in the lower layer may be the evidence of a strong anisotropy induced by preferred orientation of ice crystals and by fine layering of soft and hard ice layers. A large variation of ice viscosity with depth is therefore expected and heterogeneous flowing of the polar ice sheet. This heterogeneous flowing may invalidate the use at great depth of the ice dating models based on monotonic layer thinning.
Programme 906
Campaign
Address
Corporate Author Thesis Bachelor's thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0956-540X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 3828
Permanent link to this record
 
 
Author (down) Wittlinger G. & Farra V.
Title Converted waves reveal a thick and layered tectosphere beneath the Kalahari super-craton Type Journal Article
Year 2007 Publication Earth and planetary science letters Abbreviated Journal Earth Planet. Sci. Lett.
Volume 254 Issue Pages 404-415
Keywords
Abstract
Programme 133;906
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0012-821X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 4994
Permanent link to this record
 
 
Author (down) Winton, H., Frey, M., Haigh, J., Mulvaney, R., Pyle, J., Savarino, J., Tuckwell, R., Weller, R., and Yang, X.
Title Air-snow transfer of nitrate in Dronning Maud Land, East Antarctica Type Book Chapter
Year 2018 Publication SCAR/IASC open science conference 2018, Davos, Switzerland Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Programme 1177
Campaign
Address
Corporate Author Thesis Bachelor's thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7424
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Author (down) Winton V.H.L., Ming A., Caillon N., Hauge L. Jones A.E., Savarino J., Yang X., Frey M.M.
Title Type Journal
Year 2020 Publication Atmospheric Chemistry and Physics Abbreviated Journal
Volume 20 Issue 9 Pages
Keywords
Abstract
Programme 1177
Campaign
Address
Corporate Author Thesis Bachelor's thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1680-7316 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7855
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Author (down) Winters Kraig B, Bouruet-Aubertot Pascale, Gerkema Theo,
Title Critical reflection and abyssal trapping of near-inertial waves on a -plane Type Journal Article
Year 2011 Publication Journal of Fluid Mechanics Abbreviated Journal
Volume 684 Issue Pages 111-136
Keywords
Abstract ABSTRACT We consider near-inertial waves continuously excited by a localized source and their subsequent radiation and evolution on a two-dimensional $\ensuremath{\beta} $-plane. Numerical simulations are used to quantify the wave propagation and the energy flux in a realistically stratified ocean basin. We focus on the dynamics near and poleward of the inertial latitude where the local value of the Coriolis parameter $f$ matches the forcing frequency $\sigma $, contrasting the behaviour of waves under the traditional approximation (TA), where only the component of the Earths rotation aligned with gravity is retained in the dynamics, with that obtained under the non-traditional approach (non-TA) in which the horizontal component of rotation is retained. Under the TA, assuming inviscid linear wave propagation in the WKB limit, all energy radiated from the source eventually propagates toward the equator, with the initially poleward propagation being internally reflected at the inertial latitude. Under the non-TA however, these waves propagate sub-inertially beyond their inertial latitude, exhibiting multiple reflections between internal turning points that lie poleward of the inertial latitude and the bottom. The numerical experiments complement and extend existing theory by relaxing the linearity and WKB approximations, and by illustrating the time development of the steadily forced flow and the spatial patterns of energy flux and flux divergence. The flux divergence of the flow at both the forcing frequency and its first harmonic reveal the spatial patterns of nonlinear energy transfer and highlight the importance of nonlinearity in the vicinity of near-critical bottom reflection at the inertial latitude of the forced waves.
Programme 1015
Campaign
Address
Corporate Author Thesis
Publisher Cambridge Journals Online Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-1120 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 3440
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Author (down)
Title Explaining the disjunct distributions of austral plants: the roles of Antarctic and direct dispersal routes Type Journal Article
Year 2015 Publication Journal of Biogeography Abbreviated Journal
Volume 42 Issue 7 Pages 1197-1209
Keywords
Abstract Aim. Dispersal explains the disjunct distributions of many austral plant lineages.
However, the role of Antarctica is largely uncertain and the routes of
dispersal have remained speculative. Based on niche conservatism we can make
predictions about the timing of disjunction establishment, as well as the availability
of direct transoceanic, Antarctic stepping-stone, and out-of-Antarctica
dispersal routes over time. We evaluate these predictions using molecular
divergence time estimates for the establishment of disjunct distributions across
multiple plant lineages.

Location. Southern Hemisphere.

Methods. We estimated the timing of disjunction establishment and determined
habitat affinities for 72 austral plant groups. We used Wilcoxon rank
sum tests to compare the timing of disjunction establishment between cold
and temperate climate lineages for the full data set, as well as within several
subsets. We compared our results with those from a literature survey.

Results. As niche conservatism predicts, the timing of disjunction establishment
in cold and temperate climate austral lineages is consistent with the availability
of the corresponding habitats over time. Our results also suggest that
disjunction establishment has involved a combination of Antarctic and direct
dispersal routes. For cold climate lineages, both out-of-Antarctica and direct
dispersal routes are required to explain the observed estimates, while stepping
stone routes cannot be ruled out. It appears that for these lineages the importance
of the three dispersal routes differs with environmental, geographical and
temporal context.

Main conclusions. Both direct and Antarctic dispersal routes are necessary to
explain the establishment of contemporary austral distributions. Evidence that
some taxa were, until recently, restricted to Antarctica changes how we view
the evolutionary histories of austral floras and the lineages they contain. Moreover,
that we detect differences in the importance of alternative dispersal routes
suggests that long-distance plant dispersal processes can be explicitly incorporated
into models of climate change response.
Programme 1116
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0270 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 6142
Permanent link to this record
 
 
Author (down) Winkworth RC, Hennion F, Wagstaff SJ
Title Origins and evolution of plant diversity on the southern lands: new insights from large phylogenies. VII Southern Connection Congress, Dunedin, New-Zealand, 19-25 January 2013 Type Conference - International - Communication
Year 2013 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Programme 136
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 4349
Permanent link to this record
 
 
Author (down) Winkworth RC, Hennion F, Prinzing A, Hermant M, Wagstaff SJ
Title Antarctica helped shape Southern Hemisphere plant distribution patterns. VII Southern Connection Congress, Dunedin, New-Zealand, 19-25 January 2013 Type Conference - International - Poster
Year 2013 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Programme 136
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 4348
Permanent link to this record
 
 
Author (down) Winkworth R.C., Hennion F., Hermant M., Prinzing A. & Wagstaff S.J.
Title The role of Antarctica and the subantarctic islands in south hemisphere plant dispersal Type Conference - International - Poster
Year 2009 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract Xth SCAR International Biology Symposium, Sapporo, Japon, 26-31/07/2009
Programme 136
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 5802
Permanent link to this record
 
 
Author (down) Winkworth R.C.
Title Type Conference - International - Communication
Year 2012 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract invited seminar
Programme 136
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 4289
Permanent link to this record