Formation of patterned ground and sublimation till over Miocene glacier ice in Beacon Valley, southern Victoria Land, Antarctica

2002 ◽  
Vol 114 (6) ◽  
pp. 718-730 ◽  
Author(s):  
D.R. Marchant ◽  
A.R. Lewis ◽  
W.M. Phillips ◽  
E.J. Moore ◽  
R.A. Souchez ◽  
...  
Keyword(s):  
Patterned Ground ◽  
Victoria Land ◽  
Glacier Ice

Distribution and origin of patterned ground on Mullins Valley debris-covered glacier, Antarctica: the roles of ice flow and sublimation

2006 ◽  
Vol 18 (3) ◽  
pp. 385-397 ◽  
Author(s):  
Joseph S. Levy ◽  
David R. Marchant ◽  
James W. Head
Keyword(s):  
Patterned Ground ◽  
Ice Flow ◽  
Victoria Land ◽  
Material Weaknesses ◽  
Rapid Flow ◽  
Glacier Ice ◽  
Ice Velocity ◽  
Formation And Evolution ◽  
Structural Stresses ◽  
Glacier Flow

We map polygonally patterned ground formed in sublimation tills that overlie debris-covered glaciers in Mullins Valley and central Beacon Valley, in southern Victoria Land, Antarctica, and distinguish five morphological zones. Where the Mullins Valley debris-covered glacier debouches into Beacon Valley, polygonal patterning transitions from radial (orthogonal) intersections to non-oriented (hexagonal) intersections, providing a time-series of polygon evolution within a single microclimate. We offer the following model for polygon formation and evolution in the Mullins Valley system. Near-vertical cracks that ultimately outline polygons are produced by thermal contraction in the glacier ice. Some of these cracks may initially be oriented radial to maximum surface velocities by pre-existing structural stresses and material weaknesses in the glacier ice. In areas of relatively rapid flow, polygons are oriented down-valley forming an overall fan pattern radial to maximum ice velocity. As glacier flow moves the cracks down-valley, minor variations in flow rate deform polygons, giving rise to deformed radial polygons. Non-oriented (largely hexagonal) polygons commonly form in regions of stagnant and/or near-stagnant ice. We propose that orientation and morphology of contraction-crack polygons in sublimation tills can thus be used as an indicator of rates of subsurface ice flow.

scholarly journals Ground ice in the Northern Foothills, northern Victoria Land, Antarctica

2004 ◽  
Vol 39 ◽  
pp. 495-500 ◽  
Author(s):  
Mauro Guglielmin ◽  
Hugh M. French
Keyword(s):  
Oxygen Isotope ◽  
Ross Sea ◽  
Progress Report ◽  
Ground Ice ◽  
Lake Ice ◽  
Near Surface ◽  
Victoria Land ◽  
Different Types ◽  
Glacier Ice ◽  
Surface Ice

AbstractThis progress report classifies the different types of ground-ice bodies that occur in the Northern Foothills, northern Victoria Land, Antarctica. Oxygen isotope variations are presented, but interpretation is kept to a minimum pending further investigations. Surface ice, as distinct from moving glacier ice, occurs in the form of widespread buried (‘dead’) glacier ice lying beneath ablation (sublimation) till, together with perennial lake ice, snow banks and icing-blister ice.’Dry’ permafrost is uncommon, and interstitial ice is usually present at the base of the active layer and in the near-surface permafrost. This probably reflects the supply of moisture from the Ross Sea and limited sublimation under today’s climate. Intrusive ice occurs as layers within perennial lake-ice covers and gives rise to small icing blisters. Small ice wedges found beneath the furrows of high-centered polygons appear to agree with the model of sublimation-till development proposed by Marchant and others (2002).

scholarly journals Permafrost as a climatic indicator in northern Victoria Land, Antarctica

1999 ◽  
Vol 29 ◽  
pp. 131-135 ◽  
Author(s):  
M. Guglielmin ◽  
F. Dramis
Keyword(s):  
Ground Ice ◽  
Patterned Ground ◽  
Thermal Inversion ◽  
Ground Temperatures ◽  
The North ◽  
Victoria Land ◽  
Investigation Methods ◽  
Isotopic Analyses ◽  
History Of ◽  
Rock Glaciers

AbstractKnowledge of permafrost characteristics and distribution in Antarctica and their relationships with present and past climates is still poor. This paper reports investigations on permafrost in an area located between Nansen Ice Sheet to the south and Mount Melbourne (2732 m a.s.l.) to the north. Investigation methods included geomorphological surveys and geoelectrical soundings as well as crystallography, chemical and isotopic analyses of the ground ice. Geomorphological surveys helped to explain the relationships between periglacial landforms (e.g. rock glaciers and patterned ground) and the glacial history of the area. Geoelectrical soundings allowed us to define different ground-ice units in the ice-free areas. Each unit was characterised by a different type of permafrost (dry or ice-poor permafrost, marine or continental massive buried ice and sub-sea permafrost). To identify the nature of ground ice, trenches were dug and some shallow boreholes were drilled to a maximum depth of-3.6 m in massive buried ice. Samples of both ice-poor permafrost and massive ice were collected and analyzed. Chemical, isotopic δ18O and crystal analyses were also carried out. The relationships between climate and thermal regimes of the active layer and the upper part of permafrost were determined using a monitoring station for ground temperatures at Boulder Clay Glacier, near the Italian Antarctic station. During winter, there were several significant thermal-inversion events in the ground, which cannot be explained only by air-temperature changes, suggesting a possible influence of winter snowfall, even if these events are usually considered very rare.

scholarly journals Vocabulaire périglaciaire bilingue

2005 ◽  
Vol 6 (12) ◽  
pp. 201-226 ◽  
Author(s):  
Louis-Edmond Hamelin ◽  
Peter Clibbon
Keyword(s):  
Systematic Study ◽  
Cold Climate ◽  
Frozen Ground ◽  
Patterned Ground ◽  
Chemical Erosion ◽  
Action Effect ◽  
Climate Action ◽  
French And English ◽  
Glacier Ice ◽  
English Speaking

A considerable lack of agreement exists, particularly between French and English-speaking geomorphologists, on the precise use of many periglacial terms, and up to the presenty there bas been little correlation of the periglacial terminology of these two languages. Accordingly, the authors have prepared a bilingual glossary of 900 periglacial terms in an attempt to eliminate some of this confusion. Many of the problems encountered in the preparation of this glossary result from different conceptions of the terms « periglacial » and « périglaciaire ». Periglacial studies are generally considered to involve analyses of permanently frozen ground, patterned ground and frost-shattering, whereas the term « périglaciaire »refers to the systematic study of all « cold »processes (except those associated with glacier ice) and their resultant phenomena. The term thus includes, amongst other things, gelifraction, gelifluction, geliturbation, fluvioperiglacial action, effect of sea, lake, river and ground ice, windwork in areas of cold climate, action of snow, and chemical erosion by meltwater.

scholarly journals Buried ice in Kennar Valley: a late Pleistocene remnant of Taylor Glacier

2017 ◽  
Vol 29 (3) ◽  
pp. 239-251 ◽  
Author(s):  
Kate M. Swanger
Keyword(s):  
Late Pleistocene ◽  
Ice Cores ◽  
Dry Valleys ◽  
Patterned Ground ◽  
Outlet Glacier ◽  
Air Bubble ◽  
Isotopic Analyses ◽  
Stable Isotopic ◽  
Glacier Ice ◽  
Taylor Glacier

AbstractBuried glacier ice is common in the McMurdo Dry Valleys and under ideal climatic and geomorphological conditions may be preserved for multimillion-year timescales. This study focuses on the analysis of ~300 m2 of buried glacier ice in lower Kennar Valley, Quartermain Range. The mapped ice is clean,<10 m thick and covered by a~25 cm sandy drift. The mouth of Kennar Valley is occupied by a lobe of Taylor Glacier, an outlet glacier from Taylor Dome. Based on ice–sediment characteristics, air bubble concentrations and stable isotopic analyses from three ice cores, the lower Kennar Valley ice is glacial in origin. These data coupled with a previously reported exposure age chronology indicate that the buried ice was deposited by a late Pleistocene advance of Taylor Glacier, probably during an interglacial interval. The surface of the buried glacier ice exhibits a patterned ground morphology characterized by small, dome-shaped polygons with deep troughs. This shape possibly reflects the final stages of ice loss, as stagnant, isolated ice pinnacles sublimate in place. This study highlights how polygon morphology can be used to infer the thickness of clean buried ice and its geomorphological stability throughout Antarctica, as well as other in cold, arid landscapes.

scholarly journals Morphology of bottom surfaces of glacier ice tongues in the East Antarctic region

2001 ◽  
Vol 44 (1) ◽  
Author(s):  
C. Bianchi ◽  
M. Chiappini ◽  
I. E. Tabacco ◽  
A. Passerini ◽  
A. Zirizzotti ◽  
...  
Keyword(s):  
Water Interface ◽  
Echo Signal ◽  
Ablation Process ◽  
Antarctic Region ◽  
Victoria Land ◽  
Morphology And Structure ◽  
Radio Echo Sounding ◽  
Glacier Ice ◽  
System Data ◽  
Ice Water

During three Antarctic summer campaigns (1995/97/99) Radio Echo Sounding (RES) system data from some glacier ice tongues in the East Antarctic regions between Victoria Land and George V Land were collected. The morphology and structure of the bottom surfaces deduced from the electromagnetic interpretation of echo signal were observed. The bottom surfaces at the ice/water interface show either irregular or flat contours or both. Some ice tongues are nearly perfectly flat, others show clear signs of irregularities while three of them have good regular spaced rippled bottom surfaces. The latter structures are well-evident in the longitudinal traverse of the tongues, whereas the transversal paths do not show the same features. This particular shape of the bottom surfaces related to the ablation process and detachment mechanism could be interesting especially to determine some physical characteristics and the possible fracture points of the ice tongues.

scholarly journals Patterned Ground on an Active Medial Moraine, Jotunheimen, Norway

1979 ◽  
Vol 22 (87) ◽  
pp. 396-401 ◽  
Author(s):  
C. K. Ballantyne
Keyword(s):  
Coarse Sand ◽  
Patterned Ground ◽  
Debris Cover ◽  
Glacier Ice

AbstractSorted circles and nets formed on the surface of the principal medial moraine on Storbreen, Jotunheimcn, Norway, are described. These consist of “islands” of coarse sand, granules, and small pebbles, surrounded by pebbles and cobbles and underlain by small domes of glacier ice. It is suggested that patterned ground formation on the moraine results from differential ablation in areas of thin (&lt;200 mm) debris cover near the glacier snout, where melting is relatively rapid. It is unlikely that supraglacial patterned ground could survive deposition.

scholarly journals Patterned Ground on an Active Medial Moraine, Jotunheimen, Norway

1979 ◽  
Vol 22 (87) ◽  
pp. 396-401
Author(s):  
C. K. Ballantyne
Keyword(s):  
Coarse Sand ◽  
Patterned Ground ◽  
Debris Cover ◽  
Glacier Ice

AbstractSorted circles and nets formed on the surface of the principal medial moraine on Storbreen, Jotunheimcn, Norway, are described. These consist of “islands” of coarse sand, granules, and small pebbles, surrounded by pebbles and cobbles and underlain by small domes of glacier ice. It is suggested that patterned ground formation on the moraine results from differential ablation in areas of thin (<200 mm) debris cover near the glacier snout, where melting is relatively rapid. It is unlikely that supraglacial patterned ground could survive deposition.

Relationships between periglacial features and vegetation development in Victoria Land, continental Antarctica

2010 ◽  
Vol 22 (6) ◽  
pp. 703-713 ◽  
Author(s):  
N. Cannone ◽  
M. Guglielmin
Keyword(s):  
Ground Surface ◽  
The Arctic ◽  
Ecological Niches ◽  
Vegetation Patterns ◽  
Patterned Ground ◽  
Vegetation Development ◽  
Victoria Land ◽  
Continental Antarctica ◽  
Different Types ◽  
The Antarctic

AbstractThe relationships between vegetation patterns and periglacial features and their underlying ecology are still poorly understood and lack specific investigations in Antarctica. Here we present the results of vegetation colonization of different types of sorted patterned ground and gelifluction features (lobes and terracettes) at four sites in northern Victoria Land. This paper aims to understand the relationships between vegetation and the most widespread periglacial features in Victoria Land, discuss the role of periglacial features and vegetation in determining the ground surface temperature, and assess whether periglacial features provide ecological niches for vegetation colonization and development. Vegetation patterns are influenced by the feature type, mainly relating to patterned ground and debris island versus gelifluction features. The relations between vegetation and the periglacial features investigated in continental Antarctic are similar to those described for the Arctic, although in this part of the Antarctic vegetation is exclusively composed of cryptogams. Frost heave, ground texture and relief associated with different types of periglacial features provide a range of ecological niches sustaining vegetation biodiversity. Our data confirm the importance of periglacial features in shaping flora and vegetation biodiversity, as previously assessed only for the soil fauna in continental Antarctic.

Sign in / Sign up

Export Citation Format

Share Document