The Impact of Lithology on Fjord Morphology

TY - JOUR

T1 - The Impact of Lithology on Fjord Morphology

AU - Bernard, M.

AU - Steer, P.

AU - Gallagher, K.

AU - Egholm, D. L.

N1 - Publisher Copyright: © 2021. American Geophysical Union. All Rights Reserved.

PY - 2021/8

Y1 - 2021/8

N2 - Assessing the impact of glaciations on topography and the co-evolution of ice-sheet dynamics requires a thorough understanding of the factors that control fjord morphology. We investigate the role of lithology on glacial valley form using topographic analyses and numerical landscape evolution models. We measure fjord depths and widths from East Central Greenland (68°N–75°N), and find a control of lithology on fjord width, with wider fjords in softer rocks (i.e., sedimentary rocks). This dependency of fjord width to bedrock properties is predicted by a quarrying erosion law, but not by an abrasion one, when considering results from a simple two-dimensional model and a more detailed three-dimensional ice flow model (iSOSIA). Our analyses and numerical results reveal a potential control of lithology on the width of glacial valleys with glacial quarrying as a plausible responsible mechanism.

AB - Assessing the impact of glaciations on topography and the co-evolution of ice-sheet dynamics requires a thorough understanding of the factors that control fjord morphology. We investigate the role of lithology on glacial valley form using topographic analyses and numerical landscape evolution models. We measure fjord depths and widths from East Central Greenland (68°N–75°N), and find a control of lithology on fjord width, with wider fjords in softer rocks (i.e., sedimentary rocks). This dependency of fjord width to bedrock properties is predicted by a quarrying erosion law, but not by an abrasion one, when considering results from a simple two-dimensional model and a more detailed three-dimensional ice flow model (iSOSIA). Our analyses and numerical results reveal a potential control of lithology on the width of glacial valleys with glacial quarrying as a plausible responsible mechanism.

KW - 0720

KW - 0798

KW - 4302

KW - 5415

KW - 9315

KW - fjord development

KW - glacial erosion

KW - Greenland

KW - lithology

KW - numerical models

UR - https://www.scopus.com/pages/publications/85113550075

U2 - 10.1029/2021GL093101

DO - 10.1029/2021GL093101

M3 - Letter

AN - SCOPUS:85113550075

SN - 0094-8276

VL - 48

JO - Geophysical Research Letters

JF - Geophysical Research Letters

IS - 16

M1 - e2021GL093101

ER -