Department or Program
As temperate glaciers continue to retreat, quantifying change through melt and fracture processes remains critical priorities. The fracture mechanics of ice are poorly constrained by in situ observations, and this work endeavors to examine crevassing through field methods and remote sensing observations. This thesis, focused on the Vaughan Lewis Icefall in Juneau, Alaska, explores different methods of conducting field work in crevassed regions and understanding fracture through local observations in conjunction with empirically derived models and satellite observations.
Very little fieldwork has been conducted in densely crevassed regions such as the Vaughan Lewis Icefall. Fieldwork conducted on crevassed areas possesses a high safety risk. This study collected depth measurements ranging from 2.59m to greater than 53.21 m and compared them to the model outputs from the Zero Stress Model and Linear Elastic Fracture Mechanics Model. Using a local strain survey, strain rates in the area ranged from 0.4321 a-1 and a maximum of 0.7079 a-1 . Stresses ranging from 75-211 kPa were found in the area using Glen’s Flow Law. This study found that the available models cannot fully represent the complex variability found within the study site on the Vaughan Lewis Icefall and that more field work is needed to recalibrate existing models.
Remote sensing allows for safe continuous monitoring of icefalls. Using Continuum Damage Mechanics, an algorithm was derived to model damage density of the icefall through converting images using CMYK Channel rendering to bridge the resolution gap between high resolution drone imagery and satellite imagery of the icefall’s complex fracture patterns were mapped using a damage density plot. This algorithm was then used to produce a data processing pipeline that allowed for the comparison of satellite images of the Vaughan Lewis Icefall from xi late July/early August 2017 through 2021. By comparing total damage densities of each image to average temperature and precipitation data of the Vaughan Lewis Icefall, average temperature is observed to have a major influence on the damage density of the icefall.
Level of Access
Restricted: Embargoed [Open Access After Expiration]
Date of Graduation
Bachelor of Arts
Gichner, Cecilia G., "Quantifying Crevassing, Damage, and Deformation on the Vaughan Lewis Icefall, Alaska" (2022). Honors Theses. 402.
Number of Pages