Document Type
Article
Abstract
Lemon Creek Glacier, a temperate valley glacier in the Juneau Icefield of Southeast Alaska, is the site of long running (>60 years) glaciological studies. However, the most recent published estimates of its thickness and subglacial topography come from two ∼50 years old sources that are not in agreement and do not account for the effects of years of negative mass balance. We collected a 1-km long active-source seismic line on the upper section of the glacier parallel and near to the centerline of the glacier, roughly straddling the equilibrium-line altitude. We used these data to perform joint reflection-refraction velocity modeling and reflection imaging of the glacier bed. We find that this upper section of Lemon Creek Glacier is as much as 150 m (∼65%) thicker than previously suggested with a large overdeepening in an area previously believed to have a uniform thickness. Our results lead us to reinterpret the impact of basal motion on ice flow and have a significant impact on expectations of subglacial hydrology. We suggest that further efforts to develop a whole-glacier model of subglacial topography are necessary to support studies that require accurate models of ice thickness and subglacial topography.
Publication Date
3-26-2021
Recommended Citation
Veitch, Stephen A.; Karplus, Marianne; Kaip, Galen; Gonzalez, Lucia F.; Amundson, Jason M.; and Bartholomaus, Timothy C., "Ice thickness estimates of Lemon Creek Glacier, Alaska, from active-source seismic imaging" (2021). Faculty, Staff, and Students. 99.
https://ualaska.researchcommons.org/uas_sas_facpubs/99
Handle
http://hdl.handle.net/11122/12850