La teneur en oxygène 18 montre qu'une couche de glace blanche en bordure de la BarnesIceCap date du Pléistocène. A partir d'un modèle d'écoulement glaciaire, on estime l'épaisseur de la couche au centre de la calotte: environ 8m. Une autre
The basal ice and debris sequence at the margin of an equatorial icecap| El Cotopaxi, Ecuador
This paper describes the basal ice sequence observed at the margins of two glaciers descending from the icecap of El Cotopaxi, an active volcano, and considers the implications of these observations for the understanding of basal ice processes
Pollen dispersal and deposition on the Quelccaya IceCap, Peru
Andes ; Biogeography ; High mountain ; Ice core ; Ice sheet ; Palynology ; Peru ; Tropical zone
This study attempts to utilize 15 surface snow samples, taken on the Quelccaya IceCap, southern Peru, in late August of 2000, to help answer some basic questions of pollen dispersal and deposition on tropical Andean icecaps.
Evaluation of remote sensing techniques for ice-area classification applied to the tropical Quelccaya IceCap, Peru
Andes ; Classification ; Deglaciation ; Glacier ; Ice cover ; Peru ; Remote sensing ; Satellite imagery
La déglaciation des Andes nécessite l'étude de méthodes pour déterminer l'importance de la glace des glaciers à partir d'images par satellite. Plusieurs techniques pour décrire l'englacement sont évaluées au travers de l'application au Quelccaya Ice
Landscapes of cold-centred Late Wisconsinan icecaps, Arctic Canada
Arctic Ocean;Arctic Region ; Canada ; Cold area ; Geomorphology ; Glacial features ; Glaciology ; Ice sheet;Icecap;Inlandsis ; Meltwater ; Model ; Quaternary ; Wisconsinan
Uplands of the Canadian Arctic Islands supported Late Wisconsinan icecaps that developed two landscape zones reflecting basal thermal conditions regulated by long-sustained ice flow patterns. Central cold-based zones protected older glacial
and preglacial landscapes while peripheral warm-based zones scoured and otherwise altered their beds. Some geomorphic effects are independent of icecap scale, others vary with scale.
Identification of annual layers in superimposed ice from Storoyjokulen in northeastern Svalbard
This pilot study shows that the identification of summer surfaces in superimposed ice is possible on icecaps like Storoyjokulen which, in turn, means that the dating of this ice is possible.
Potential to recover climatic information from Scandinavian ice cores : an example from the small icecap Riukojietna
Climatic variability ; Cold area ; Europe ; Geochemistry ; Ice ; Ice core ; Isotope analysis ; Little ice age ; Northern Europe ; Oxygen 18 ; Palaeoclimatology ; Scandinavia ; Twentieth Century
The AA. have studied a 33.7 m deep ice core from a small polythermal Scandinavian icecap to determine whether it is possible to recover pre-20th century climatic information from the glacier. Results demonstrate that ice cores from glaciers
Antarctica ; Earth surface processes ; Esker ; Glacial features ; Glacier margin ; Ice sheets;Icecap;Inlandsis ; Moraines
The eskers described in this paper have formed on the surface of cold ice at the margin of the Antarctic ice sheet. The location, orientation, sedimentary properties and field relationships of the eskers are described and a model of their formation
The AA. discuss the significance of the Penny icecap dust record in relation to the glacial and environmental history of the Canadian Arctic. Comparisons are made to the Greenland Ice Sheet Project 2 (GISP2) dust record in order to differentiate
between regional and hemispheric influences on atmospheric dust deposition. This study further demonstrates how valuable records of regional-scale paleoenvironmental changes can be developed from circum-Artic icecaps, even those affected by considerable
Mass balance and area changes of four High Arctic plateau icecaps, 1959-2002
Aerial photography ; Arctic Region ; Canada ; Climatic variation ; Cold area ; Ellesmere ; Glacier ; Glacier mass balance ; Glacier retreat ; Global Positioning System ; Ice sheet ; Northwest Territories
The AA. report the results of recent mass balance and GPS area measurements on 4 small stagnant plateau icecaps located on the Hazen Pateau of Ellesmere Island, Nunavut, Canada, from 1999-2002. They compared these measurements with topographic maps
and aerial photography from 1959 and with previously published data. The icecaps reached a Holocene maximum and were several times larger during the Little Ice Age (LIA) and their current recession reflects an adjustment to post-LIA climatic conditions.
Preservation of landforms under ice sheets and icecaps
Archaeology ; Arctic Region ; Cold area ; Drumlin ; Glacial features ; Ice sheet ; Inherited features ; Periglacial features ; Vegetation
This article addresses the question of whether or not distinct glacial and non-glacial landforms can survive beneath ice sheets and icecaps with little or no morphological alteration. In glaciated areas, patches preserved under dry (cold)-based
conditions provide important windows towards the past, showing landscapes that were destroyed in surrounding areas affected by wet-based and eroding ice. Some consequences for the research fields of non-glacial geomorphology, archaeology and botany include
The southern margin of the Late Cainozoic icecap on the Central Plateau of Tasmania
This paper reports new geomorphological mapping, and reviews the extent, dating, pattern, and nature of past glaciation of the Tasmania's Central Plateau. The Last Glacial Maximum (LGM) ice limits on the southern part of the Central Plateau
A conceptual model for growth and decay of the Cordilleran Ice Sheet
British Columbia ; Canada ; Climatic variation ; Glacial features ; Glacier fluctuation ; Ice sheet;Icecap;Inlandsis ; Model ; Quaternary
The objective of this paper is to present the general concepts that have been developed and used to explain the general pattern of growth and decay of the Cordilleran Ice Sheet.
Climatic variation ; Forecast;Prediction ; Glacial features ; Glacier mass balance ; Ice sheets;Icecap;Inlandsis ; Model ; Scotland ; Topography ; United Kingdom
This paper uses a numerical ice sheet model to investigate the role of topography in influencing ice sheat growth. The model is applied to the maritime, mid-latitutde uplands of Scotland and relies on a series of assumptions about mass balance
, topography, and ice flow. It is driven by an imposed pattern of temperature change. The model is able to predict effectively the extent and thickness of the Loch Lomond ice sheet, using a palaeotemperature curve based on Coleoptera assemblages.
Ice-core pollen record of climatic changes in the central Andes during the last 400 yr
Andes ; Bolivia ; Central America ; Climatic variation ; Little ice age ; Mountain ; Palynology ; Peru ; Pollen diagram
This paper presents a high-resolution ice-core pollen record from the Sajama IceCap, Bolivia, that spans the last 400 yr. The pollen record corroborates the oxygen isotopic and ice accumulation records from the Quelccaya IceCap in southern Peru
and supports the scenario that the Little Ice Age (LIA) consisted of 2 distinct phases, a wet period and a dry period. The striking similarity between the Sajama and Quelccaya proxy records suggests that climatic changes during the Little Ice Age occurred
A study of snow and ice temperature on Vestfonna, Svalbard, 1956, 1957 and 1958
To obtain understanding of the energy budget temperature measurements were carried out on the summit and near the western margin of the icecap in summer. Variations of the cold content in the upper 10 m are calculated. Combined with the amount
of the heat in ablation the magnitude of the total energy used for warming and melting the ice is obtained.