Evolution of rock glaciers and alpine glaciers: A model–model approach
نویسنده
چکیده
The effects of horizontal stress transmission on the transient evolution of non-linear viscous bodies having aspects ratios similar to active alpine rock glaciers is investigated. This is done through a comparison between a shallow-ice model, which predicts material flux to be a local function of thickness and slope, and a finite-element model, which solves the full Stokes problem. For length-to-thickness ratios ranging from one to ten, the surface evolution and surface velocities calculated with these two models are markedly different. Nevertheless some other aspects of the transient evolution are quite insensitive to the different sets of simplifications on which the two flow models are based. The rate-of-advance of the snout is, for example, almost identical in both cases. Length changes of rock glaciers and alpine glaciers can, thus, be calculated accurately without accounting for the transmission of horizontal stresses. Permafrost, Phillips, Springman & Arenson (eds) © 2003 Swets & Zeitlinger, Lisse, ISBN 90 5809 582 7
منابع مشابه
DETECTION AND QUANTIFICATION OF ROCK GLACIER DEFORMATION USING ERS D-InSAR DATA
Synthetic Aperture Radar (SAR) systems normally record both the amplitude and the phase of the backscattered echoes. However, the phase of a single backscattered image is of no use and therefore, conventionally the amplitude or intensity image is usually provided to the user. But on the contrary, the phase difference of two backscattered SAR images of the same area on the ground taken at slight...
متن کاملUsing Quad-Pol and Single-Pol RADARSAT-2 Data for Monitoring Cold Alpine and Outlet Antarctic Glaciers
This paper presents some applications of the Maximum Likelihood (ML) texture tracking on displacement estimation of some alpine and antarctic glaciers surfaces. This method is adapted to the statistical characteristic of the new High Resolution (HR) Polarimetric SAR (PolSAR) data. The ML texture tracking method is firstly reminded and a statistical model of HR PolSAR data is explained. The main...
متن کاملUsing Quad-pol and Single-pol Radarsat-2 Data for Monitoring Alpine and Outlet Antarctic Glaciers
This paper presents some applications of the Maximum Likelihood (ML) texture tracking on displacement estimation of some alpine and antarctic glaciers surfaces. This method is adapted to the statistical characteristic of the new High Resolution (HR) Polarimetric SAR (PolSAR) data. The ML texture tracking method is firstly reminded and a statistical model of HR PolSAR data is explained. The main...
متن کاملThe Place of Glaciers in Natural and Cultural Landscapes
In the fi rst half of the nineteenth century, glaciers taught us a great lesson about the earth. In the 1820s and 1830s, Swiss naturalists established the existence of the Ice Age. Their key insight was the fact that the small glaciers found at high elevations in mountainous regions were remnants of vast sheets of ice that once had covered large portions of the earth’s surface. They combined ma...
متن کاملForecasting temperate alpine glacier survival from accumulation zone observations
Temperate alpine glacier survival is dependent on the consistent presence of an accumulation zone. Frequent low accumulation area ratio values, below 30%, indicate the lack of a consistent accumulation zone, which leads to substantial thinning of the glacier in the accumulation zone. This thinning is often evident from substantial marginal recession, emergence of new rock outcrops and surface e...
متن کامل