Alexander D. Sodeman, PhD

Glacial Geologist and Geomorphologist

Insights into the Subglacial Hydrology of the Cordilleran Ice Sheet from Unique Meltwater Landforms


Conference paper


Alexander Sodeman, Tracy Brennand
AGU Fall Meeting Abstracts, vol. 2023, 2023, pp. C11D--1066

Cite

Cite

APA   Click to copy
Sodeman, A., & Brennand, T. (2023). Insights into the Subglacial Hydrology of the Cordilleran Ice Sheet from Unique Meltwater Landforms. In AGU Fall Meeting Abstracts (Vol. 2023, pp. C11D–1066).


Chicago/Turabian   Click to copy
Sodeman, Alexander, and Tracy Brennand. “Insights into the Subglacial Hydrology of the Cordilleran Ice Sheet from Unique Meltwater Landforms.” In AGU Fall Meeting Abstracts, 2023:C11D–1066, 2023.


MLA   Click to copy
Sodeman, Alexander, and Tracy Brennand. “Insights into the Subglacial Hydrology of the Cordilleran Ice Sheet from Unique Meltwater Landforms.” AGU Fall Meeting Abstracts, vol. 2023, 2023, pp. C11D–1066.


BibTeX   Click to copy

@inproceedings{sodeman2023a,
  title = {Insights into the Subglacial Hydrology of the Cordilleran Ice Sheet from Unique Meltwater Landforms},
  year = {2023},
  pages = {C11D--1066},
  volume = {2023},
  author = {Sodeman, Alexander and Brennand, Tracy},
  booktitle = {AGU Fall Meeting Abstracts}
}

The subglacial hydrology of ice sheets is widely known to play a role in controlling glacial dynamics, but the presence of overlying ice prevents widespread direct observation and study. Studying past ice sheets allows for easy access to what was once the subglacial environment, informing our understanding of how both past and present ice sheets operated. A number of landforms have been revealed by recent releases of LiDAR data over the Southern Fraser Plateau in British Columbia, and this study presents results from extensive mapping and geophysical surveys across two types of landforms typically associated with subglacial hydrology. Meltwater corridors are broad, shallow landforms with clear erosional boundaries that have been identified in several paleoglacial landscapes. We identified a vast network of meltwater corridors across the study area with a wide variety of sizes, and have identified two morpho-stratigraphic types using electrical resistivity tomography (ERT) and ground penetrating radar (GPR) surveys. Exposed corridors contain a series of parallel, narrow, shallow channels that strongly resemble landforms identified in other regions as glacial curvilineations. Buried corridors consist of one or more esker-like ridges surrounded by a smooth land surface. ERT and GPR surveys show the exposed corridor morphology to be an unconformity, while the buried corridors are composed of sorted sediments overlying a channeled unconformity. Murtoos are triangular-shaped hills flanked by shallow troughs, previously identified in Scandinavia. Sedimentological and ERT surveys across the murtoos indicate the landforms are composed of the same sediment as the area lateral to the murtoos. The troughs associated with the murtoos often show undulating long profiles, with one example containing significant gravel fill. These troughs are interpreted as subglacial channels and the murtoos are therefore considered to be erosional remnants defined by their flanking troughs. These two landforms illustrate the widespread erosional impact of that subglacial meltwater flow had across the plateau and reconstructing their genesis can give further insight into the dynamics beneath modern ice sheets.