Doctoral Dissertation Research: The Mechanics of Rock Glacier Creep: A New GIS Method and A Possible Response to Climate Change

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Rock glaciers are considered a glacial or periglacial feature that slowly creep downslope as a result of deformation of ice that has been consolidated with angular, coarse rock. Although rock glaciers have been studied using a variety of field techniques and, more recently, with remote aerial photography analysis, much still is unknown regarding the dynamics of flow. The mechanism by which factors like micro-topography, ice content, or rock glacier form influence rock glacier behavior is unknown. Similarly, little is known of the possible existence of regional flow patterns as a result of climate change. Previous analyses have been primarily limited to the Alps in Europe. This doctoral dissertation research project will investigate the mechanics of rock glacier creep in the U.S. and Canadian Rocky Mountains, using an approach that combines analyses using high-precision temporal aerial photography and a geographic information system (GIS). The doctoral student will design a digital methodology for detecting motion of the rock glaciers to maximize the advantages of data analysis within a GIS. Rock glacier sections within a variety of different rock glacier forms will be analyzed to gain a greater comprehension of rock glacier motion. Because active rock glaciers are considered an indicator of discontinuous permafrost, a regionalized approach to rock glacier motion will be undertaken to detect climatically induced changes in permafrost distribution. The methods employed in this study will resemble those presented in earlier studies, but they will incorporate GIS-based analytic procedures. A sequence of temporal air photos for rock glaciers will be selected and scanned at a high resolution. The photos will then be enhanced, orthorectified, and co-registered to a common scale. Point-to-point methods will be conducted in a GIS to temporally track large boulders and rocks. Attribute data about the points as well as ancillary data will be included to determine the factors affecting flow. Detailed digital elevational models (DEM) will also be constructed to monitor surface slumping. Vertical and horizontal velocities will be calculated for approximately five to ten rock glaciers extending across a latitudinal transect of the Rocky Mountains for dates ranging from 1940 to the present.As development and recreation continue to increase in mountainous regions, the nature and stability of these areas is threatened. Global warming will further alter stability. An important component to the alpine geomorphic system, rock glaciers, are expected to experience substantial change. Rock glaciers may become unstable or may cause catastrophic releases of water that could damage nearby residential areas, communication towers, ski lifts, hiking paths, campgrounds, or other recreational areas. The results of this study should help monitor the form rock glaciers. They also will provide a better understanding of the dynamics of rock glacier flow, which will enhance our understanding of other rock glaciers and permafrost distribution on other terrestrial planets such as Mars. The study will develop methods using a GIS that will allow the input of ancillary data and incorporate IKONOS data for future analysis. This GIS-based format will be easily updateable and transferable to other parts of the world. As a result, this research will help advance the monitoring of global changes in permafrost. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.