Search
Results
-
Creep of Alpine permafrost, investigated on the Murtèl Rock Glacier
(1992)Permafrost and Periglacial ProcessesBorehole and surface deformation measurements from an active rock glacier in the eastern Swiss Alps are presented and analysed. Borehole deformation was measured by slope indicator and magnetic rings. Analysis of these measurements reveal two layers which behave quite differently. The upper, highly supersaturated (i.e. ice) layer undergoes steady-state creep (corresponds to a surface velocity of 5.5 to 6.0 cm/yr), overriding a non-deforming ...Journal Article -
The clogging of coarse gravel river beds by fine sediment
(1992)HydrobiologiaLaboratory investigations were carried out to examine the clogging process in coarse gravel river beds. Field samples taken from the Langeten river in Switzerland show that the intruded fine particles of the flow are deposited in the top layer of the river bed. For lower discharges the decrease of the hydraulic conductivity depends mainly on the dimensionless shear stress of the flow, the concentration of the suspended load, the hydraulic ...Journal Article -
A model of potential direct solar radiation for investigating occurrences of mountain permafrost
(1992)Permafrost and Periglacial ProcessesA model is described to compute the daily potential direct solar radiation on the basis of digital terrain models. This model is a useful tool for investigating distribution patterns of permafrost in mountain areas. An example of its application to a low-altitude permafrost site in the Northern Prealps of Switzerland is presented.Journal Article -
Wellennutzung vor dem Durchbruch?
(1992)Schweizer Ingenieur und ArchitektSchon seit vielen Jahrzehnten werden Projekte verfolgt, um die Meeresenergie zu ernten. Im Vordergrund stehen dabei Konzepte zur Nutzung der thermischen und der hydraulischen Energie. Hier wird das Augenmerk auf die letztere gerichtet, und zwar auf die Wellenenergie: Wie kann das ewige Auf und Ab der Meeresoberflache in elektrischen Strom umgewandelt werden? - Nebst einer kurzen Übersicht über das Wesen der Wellenenergie und der in ...Journal Article -
Stagniert die Gezeitennutzung?
(1992)Schweizer Ingenieur und ArchitektIm «Schweizer Ingenieur und Architekt» Heft 9 vom 27. Februar 1992 wurde der Entwicklungsstand der Wellennutzung skizziert. Eine weitere Möglichkeit, Meeresenergie zu ernten, besteht in der Gezeitennutzung. Bei dieser wird das gezeitenbedingte Auf und Ab der Meeresoberfläche in Strom umgewandelt. Als Wandler dienen Kraftwerke, die einem Niederdruck-Flusskraftwerk gleichen. Was sind die Besonderheiten? Wo steht die Entwicklung heute?Journal Article -
-
Improvement of flow in final settling tanks
(1992)Journal of Environmental EngineeringPoor flow in final settling tanks may be the result of neglecting the effects of density current. This can be countered when inserting guiding flow elements, such as the inlet and the barrier walls in the tank. Based on a simple approach, the optimum height of the inlet aperture increases with both the overflow rate per unit width and the return sludge ratio, but decreases with the relative difference of density. Further, a central barrier ...Journal Article -
Borehole logging in alpine permafrost, upper Engadin, Swiss Alps
(1992)Permafrost and Periglacial ProcessesIn two boreholes through Alpine permafrost, borehole geophysical measurements were performed. At the borehole through rock glacier Murtèl-Corvatsch, where cores were taken, the main difficulty was to fill up the hole with water. Consequently, only some of the logging methods could be applied. Nevertheless, gamma-gamma log (and qualitatively also gamma-ray) made it possible to obtain density and to calculate ice content. At the ...Journal Article -
Evidence of intrapermafrost groundwater flow beneath an active rock glacier in the Swiss Alps
(1992)Permafrost and Periglacial ProcessesTemperature measurements in borehole 2/1987 through rock glacier Murtèl Corvatsch revealed a very high mean heat flow of 150 mW/m2. Between 52 m and 56 m depth, seasonal variations are observed; above and underneath this zone temperatures have remained negative during the last 4 years. In addition, a zero curtain effect at the same depth hints at the existence of a water aquifer which is active mainly in summer. This phenomenon is interpreted ...Journal Article -
Permafrost research sites in the Alps: Excursions of the Int. Workshop on Permafrost and Periglacial Environments in Mountain Areas
(1992)Permafrost and Periglacial ProcessesJournal Article