A paleoclimate model of Northern Hemisphere ice sheets
A model for predicting the growth and decay of ice sheets based on the astronomical theory of climate change is presented. The purpose of the study in part is to isolate the role of the ice-sheet physics and earth response under varying ice load
by simplifying to the extreme the role of the hydrosphere-atmosphere... The model prediction lends support to the hypothesis that the nonlinearity of the ice-sheet physics is responsible for the 100,000-yr periodicity in the geological record of the late
The age relationships between Rogen moraine ridges in the Central swedish mountains and subglacially engorged valley side eskers on the mountain slopes are discussed. The movement rates of the downwasting ice remnants within the final ice-divide
area must have decreased or partly ceased already when the eskers were formed on the hillsides. The drumlinization of the Rogen type ridges thus occurred at a stage prior to the disappearance of the ice bodies between the valley sides.
Maps are presented for the subglacial topography of Storglaciären, Isfallsglaciären and Rabots glaciär in northern Sweden. The maps are results of radio-echo soundings. Isfallsglaciären consists of one isolated basin above the ice fall uhereas
storglaciären is situated in a valley which is divided into three basins. No depressions were found in Rabots glaciär. The distribution with elevation was obtained for ice thickness, bedrock and ice surface areas, and ice volumes. Data for Storglaciären: area
A = 3.1 km, ice volume V = 306 10 m, average ice depth h = 99 m, maximum ice depth H = 250 m. Data for Isfallsglaciären: A = 1.3 km, V = 93 10 m, h = 72 m, ht = 220 m. Rabots glaciär: A = 4.1 km, V = 346 10 m, h = 84 m, ht = 175 m.
West Antarctic ice-volume: the interplay of sea-level and temperature and a strandline test for absence of the ice-sheet during the last interglacial in Sea level ice and climatic change.
Large-scale variations in observed Antarctic sea ice extent and associated atmospheric circulation
The 1974 three-day averaged sea ice extent data for the Southern Ocean have been compared with 1000 mb temperature and sea level pressure fields from the Southern Hemisphere meteorological data. Three case studies are presented. The results
demonstrate an ice-atmosphere coupling of varying strength throughout the year on time scales ranging from weeks to months and on space scales ranging from synoptic to planetary. Although the results emphasize the response of the ice edge to large-scale
pressure and temperature variations, evidence is found supporting the reverse, an atmospheric response to a changing ice cover. (JPB).
Ice-pushed Lower and Middle Pleistocene deposits near Rhenen (Kwintelooijen): sedimentary-structural and lithological/granulometrical investigations
In the Kwintelooijen sandpit, located in the inside of a large ice-pushed ridge, a number of thrust sheets are exposed which were formed by pushing inland ice during the Saalian glacial time. In these glaciotectonic units periglacial and fluvial
Fluvioglacial landforms and ice margin characteristics. An example from the Torneträsk area in northern Sweden
, sediment structure and setting in relation to the retreating ice margin. A reconstruction of the ice front characteristics was made from studies of the morphology and sediment structures of fluvioglacial deposits.
Changes in ocean temperature, carbonate productivity, and ice-rafted detritus in the North Atlantic suggest that half of the Northern Hemisphere ice volume at the last glacial maximum had disappeared by 13,000 yr B.P., despite the still-extensive
limits of the ice sheets. This early thinning of the ice sheets occurred during a time when summer insolation values were slowly rising but when pollen evidence south of the ice margins indicates cold, dry air masses. We infer that this rapid early ice
disintegration (16,000 13,000yr B.P.) was caused by oceanic mechanisms: (1) rising sea level, causing increased calving along ice margins: (2) the chilling of the sea-surface by iceberg and melwater, reducing moisture extraction by the atmosphere and transport
to the ice sheets| and (3) winter freezing of the low-salinity meltwater layer, supressing local moisture extraction and the regional influx of moisture-bearing storms from lower latitudes in winter and hence starving the ice sheets. These oceanic feedback