TY - JOUR
T1 - Geomorphic and sedimentary signatures of catastrophic glacier detachments
T2 - A first assessment from Flat Creek, Alaska
AU - Jacquemart, Mylène
AU - Welty, Ethan
AU - Leopold, Matthias
AU - Loso, Michael
AU - Lajoie, Lia
AU - Tiampo, Kristy
N1 - Funding Information:
MJ was funded through the NASA Earth and Space Science Fellowhip (NESSF; grant no. 80NSSC17K0391 ), the WSL research program Climate Change Impacts on Alpine Mass Movements (CCAMM) and the Swiss National Science Foundation (grant no. 200021_184634 ). Fieldwork and logistics were covered by the U.S National Park Service, as was LL (Geoscientists in the Parks program). We kindly thank Sam McColl for the highly detailed and constructive review, as well as Achim Beylich for his editorial support and feedback.
Funding Information:
Mylene Jacquemart reports financial support was provided by Swiss National Science Foundation. Mylene Jacquemart reports financial support was provided by Swiss Federal Institute for Forest Snow and Landscape Research.
Funding Information:
Mylene Jacquemart reports financial support was provided by NASA.
Funding Information:
MJ was funded through the NASA Earth and Space Science Fellowhip (NESSF; grant no. 80NSSC17K0391), the WSL research program Climate Change Impacts on Alpine Mass Movements (CCAMM) and the Swiss National Science Foundation (grant no. 200021_184634). Fieldwork and logistics were covered by the U.S National Park Service, as was LL (Geoscientists in the Parks program). We kindly thank Sam McColl for the highly detailed and constructive review, as well as Achim Beylich for his editorial support and feedback.
Publisher Copyright:
© 2022 The Author(s)
PY - 2022/10/1
Y1 - 2022/10/1
N2 - Large-volume detachments of low-angle mountain glaciers involve the sudden mobilization of large amounts of glacier ice and lithic material in long-runout mass flows. Scientific investigations of these events have only recently brought to light their global occurrence and the similarities in the conditions under which they occur. While this recent research suggests that glacier detachments may become more frequent in a warming climate, a long-term record is largely lacking. Knowledge of the geomorphic signatures of glacier detachments could help establish such a record. Here, we present the first geomorphic and sedimentary assessment of a glacier detachment deposit. We investigate the landscape impacts of the Flat Creek glacier detachments in Alaska's St. Elias mountains through a combination of remote sensing analyses, field observations, Electrical Resistivity Tomography, and grain size and grain orientation analyses. From these data, we outline a land-system model that may help identify past glacier detachments elsewhere. Some of the most distinguishing features we documented were large bodies of buried ice-conglomerates, a rapid response of the remnant glacier ice, clusters of small-scale thermokarst ponds, countless molards, parallel striations etched into the hillslope and individual clasts, and a very long runout distance. We assess these features in terms of their longevity in the landscape and compare them to what has been described at glacier detachment sites elsewhere. Finally, we discuss to what extent glacier detachment deposits can be distinguished from deposits left by rock(−ice) avalanches, debris flows, and surging glaciers, and show that a differentiation is possible if detailed field investigations are undertaken.
AB - Large-volume detachments of low-angle mountain glaciers involve the sudden mobilization of large amounts of glacier ice and lithic material in long-runout mass flows. Scientific investigations of these events have only recently brought to light their global occurrence and the similarities in the conditions under which they occur. While this recent research suggests that glacier detachments may become more frequent in a warming climate, a long-term record is largely lacking. Knowledge of the geomorphic signatures of glacier detachments could help establish such a record. Here, we present the first geomorphic and sedimentary assessment of a glacier detachment deposit. We investigate the landscape impacts of the Flat Creek glacier detachments in Alaska's St. Elias mountains through a combination of remote sensing analyses, field observations, Electrical Resistivity Tomography, and grain size and grain orientation analyses. From these data, we outline a land-system model that may help identify past glacier detachments elsewhere. Some of the most distinguishing features we documented were large bodies of buried ice-conglomerates, a rapid response of the remnant glacier ice, clusters of small-scale thermokarst ponds, countless molards, parallel striations etched into the hillslope and individual clasts, and a very long runout distance. We assess these features in terms of their longevity in the landscape and compare them to what has been described at glacier detachment sites elsewhere. Finally, we discuss to what extent glacier detachment deposits can be distinguished from deposits left by rock(−ice) avalanches, debris flows, and surging glaciers, and show that a differentiation is possible if detailed field investigations are undertaken.
KW - Climate change
KW - Glacier detachments
KW - Land-system model
KW - Natural hazards
UR - http://www.scopus.com/inward/record.url?scp=85135414217&partnerID=8YFLogxK
U2 - 10.1016/j.geomorph.2022.108376
DO - 10.1016/j.geomorph.2022.108376
M3 - Article
AN - SCOPUS:85135414217
SN - 0169-555X
VL - 414
JO - Geomorphology
JF - Geomorphology
M1 - 108376
ER -