On the formation of the tunnel valleys of the Superior Lobe, central Minnesota
The Minnesota tunnel valleys are composed of individual segments 10-20 km long, and the segments commonly terminate in subaerial outwash fans at recessional ice margin positions. Eskers, associated with the tunnel valleys, are also composed of short
segments, frequently beginning at moulin kames and terminating at the head of outwash fans. The dominant source of the water responsible for tunnel-valley formation was seasonal meltwater from the glacier surface that reached the bed through moulins
and crevasses. The apparent continuity of the valleys resulted from the headward development of the englacial drainage system during ice retreat.
Silicon Valley. Personlichkeiten und gesellschaftliche Ideen als raumgestaltende Kräfte (Silicon Valley. Des personnalités et des idées sociales comme moteur de l'aménagement)
Aménagement régional ; Didactique ; Enseignement de la géographie ; Généralités sur la géographie ; Innovation technologique ; Mythe Silicon Valley ; Pôle de croissance
Réflexions didactiques sur le mythe de la Silicon Valley. Prise en compte des facteurs techniques et économiques.
Experimental study of wind directional variability in the vicinity of a model valley
Aeolian features ; Aeolian transport ; Aerosol ; Atmospheric pollution ; Experimentation ; Modelling ; Topography ; Valley ; Wind ; Wind speed
This paper reports the results of a preliminary study examining the effects of valley presence on airflow direction and focuses on valleys situated in areas of low relief. Wind tunnel experiments are used to visualise near-surface airflow over
a series of models representing valleys oriented at different angles to mean airflow. This study has significance to the modelling of pollution dispersal and also aeolian sediment and nutrient dynamics in desert regions.
Hypsometric forcing of stagnant ice margins: Pleistocene valley glaciers, San Juan Mountains, Colorado
Colorado ; Deglaciation ; Glacial valley ; Glacier margin ; Hypsometry ; Model ; Mountain ; Pleistocene ; Quaternary ; Topography ; United States of America
The A. uses the location of stagnant ice deposits in many San Juan valleys, Colorado, to test how valley hypsometry and topographic obstructions influence the type of margin present during valley glacier retreat.
Valley asymmetry with steeper west-facing valley sides is a common feature in the Tertiary Hills of Lower Bavaria. The purpose of this study is to examine the relation between this drainage and valley asymmetry and to review the possible causes
This paper presents the state of knowledge on the evolution of river valleys in the Upper Quaternary. It is followed by full index of localisations, where dated Vistulian and Holocene sediments were found. The transformation of river valleys
Vyvoj udoli a kvartérni tektonika Hlucinské pahorkatiny. (Valley development and Quaternary tectonics in the Hlucinska pahorkatina) (hilly land)
Dells, dry valleys, river valleys, cryopediments as well as valley asymmetry are described in the model area of Pleistocene deposits. Special attention is devoted to the role of Quaternary tectonics in valley development. The hilly land of Hlucin
California ; Central Valley ; Espace rural ; Esthétique du paysage ; Etats-Unis ; Paysage culturel ; Paysage rural ; Région agricole
The Central Valley, California's richest agricultural region, does not correspond to romantic pastoral ideals perpetuated by American high culture. The A. describes its special character as photographers have seen it and finds in its utilitarian
Some aspects of valley asymmetry in the high Drakensberg
Earth surface processes ; High mountain ; Mass movement ; Mountain ; Palaeoclimatology ; Periglacial features ; Slope ; Slope gradient ; South Africa ; Valley
Valley asymmetry at high altitudes in the Drakensberg may be the result of periglacial processes. A tentative hypothesis is presented. - (AJC)
On the mathematical description of glaciated valley cross sections
Geomorphometry ; Glacial erosion ; Glacial features ; Methodology ; Valley
The AA. examine implicit bias in power-law equation analyses introduced by the use of logarithmic data transformations, and discuss problems associated with cases where part of the original erosional form of the glacial channel or glacial valley has
Examination of seasonal pastoral migrations to alpine pastures in a valley of the northwestern Himalaya shows that increases in human population and livestock numbers are putting severe pressures on the traditional agropastoral system. - (DWG)
Population change in the upper Braldu Valley, Baltistan, 1900-1990: all is not as it seems
Demographic change ; Demographic structure ; Depopulation ; Himalaya ; Infant mortality ; Karokoram ; Local economy ; Mountain ; Pakistan ; Valley ; Village
Due mainly to high child mortality, population in the upper Braldu valley of the Karakoram range in northern Pakistan declined between 1900 and 1990. This trend is counter to the growth elsewhere in the Himalayan region. - (DWG)