Holocene uplift and rapid fluvial erosion of Iceland: a record of post-glacial landscape evolution
File(s)
Published version
Author(s)
Stucky de Quay, Gaia
Roberts, Gareth G
Rood, Dylan H
Fernandes, Victoria M
Type
Journal Article
Abstract
In actively deforming regions fluvial systems are strongly regulated by uplift. River geometries record histories of vertical motions that can be used to examine the driving forces generating topographic relief. Iceland's rapidly evolving landscapes provide an opportunity to disentangle histories of uplift generated by postglacial rebound, volcanism, dynamic support, and plate spreading. Broad knickzones observed along Iceland's large rivers, and its powerful waterfalls and deep canyons, hint that regional processes have generated significant relief. We combine high-resolution drone photogrammetry and cosmogenic 3He dating of fluvial terraces to measure the erosional history of one of Iceland's largest knickzones, Jökulsárglúfur, in the northeast part of the island. Progressive younging of terraces indicates knickpoint propagation rates of up to ∼70 cm a−1 during the last 8 ka. Knickpoint velocities appear to be controlled partly by toppling of basalt columns. These rates were used to calibrate a model that inverts Iceland's drainage networks for uplift rate histories. Calculated uplift and isostatic calculations indicate that rifting, sub-plate support, and isostatic adjustment resulted in tens to hundreds of meters of regional Holocene uplift. Our results suggest regional uplift and fluvial erosion can rapidly generate hundreds of meters of relief in post-glacial landscapes.
Date Issued
2019-01-01
Date Acceptance
2018-10-16
Citation
Earth and Planetary Science Letters, 2019, 505 (1), pp.118-130
ISSN
0012-821X
Publisher
Elsevier
Start Page
118
End Page
130
Journal / Book Title
Earth and Planetary Science Letters
Volume
505
Issue
1
Copyright Statement
© 2018 The Authors. Published by Elsevier B.V. This is an
open access article under the CC-BY license
(http://creativecommons.org/licenses/by/4.0/)
open access article under the CC-BY license
(http://creativecommons.org/licenses/by/4.0/)
Sponsor
The Royal Society
Identifier
https://www.sciencedirect.com/science/article/pii/S0012821X18306228
Grant Number
RG160020
Subjects
Science & Technology
Physical Sciences
Geochemistry & Geophysics
uplift
fluvial erosion
Iceland
Holocene
cosmogenic He-3
landscape evolution
EXTREME FLOOD EVENTS
COSMOGENIC NUCLIDES
PRODUCTION-RATES
SCALING FACTORS
MODEL
PRECIPITATION
JOKULHLAUP
DYNAMICS
FJOLLUM
JOKULSA
02 Physical Sciences
04 Earth Sciences
Geochemistry & Geophysics
Publication Status
Published
Date Publish Online
2018-10-26