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Uplift histories of Africa and Australia from linear inverse modeling of drainage inventories

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Title: Uplift histories of Africa and Australia from linear inverse modeling of drainage inventories
Authors: Rudge, JF
Roberts, GG
White, NJ
Richardson, CN
Item Type: Journal Article
Abstract: We describe and apply a linear inverse model which calculates spatial and temporal patterns of uplift rate by minimizing the misfit between inventories of observed and predicted longitudinal river profiles. Our approach builds upon a more general, nonlinear, optimization model, which suggests that shapes of river profiles are dominantly controlled by upstream advection of kinematic waves of incision produced by spatial and temporal changes in regional uplift rate. Here we use the method of characteristics to solve a version of this problem. A damped, nonnegative, least squares approach is developed that permits river profiles to be inverted as a function of uplift rate. An important benefit of a linearized treatment is low computational cost. We have tested our algorithm by inverting 957 river profiles from both Africa and Australia. For each continent, the drainage network was constructed from a digital elevation model. The fidelity of river profiles extracted from this network was carefully checked using satellite imagery. River profiles were inverted many times to systematically investigate the trade-off between model misfit and smoothness. Spatial and temporal patterns of both uplift rate and cumulative uplift were calibrated using independent geologic and geophysical observations. Uplift patterns suggest that the topography of Africa and Australia grew in Cenozoic times. Inverse modeling of large inventories of river profiles demonstrates that drainage networks contain coherent signals that record the regional growth of elevation.
Issue Date: 17-Jun-2015
Date of Acceptance: 19-Feb-2015
URI: http://hdl.handle.net/10044/1/48405
DOI: 10.1002/2014JF003297
ISSN: 2169-9011
Publisher: American Geophysical Union
Start Page: 894
End Page: 914
Journal / Book Title: Journal of Geophysical Research: Earth Surface
Volume: 120
Issue: 5
Copyright Statement: © 2015 The Authors.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License (https://creativecommons.org/licenses/by/4.0/), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Keywords: Science & Technology
Physical Sciences
Geosciences, Multidisciplinary
Geology
Uplift
Linear inversion
Africa
Australia
River profiles
Cenozoic
BEDROCK INCISION MODELS
STREAM-POWER
RIVER INCISION
LANDSCAPE EVOLUTION
SOUTH-AFRICA
SEDIMENT
TOPOGRAPHY
GEOMORPHOLOGY
PLEISTOCENE
TECTONICS
04 Earth Sciences
Publication Status: Published
Online Publication Date: 2015-02-23
Appears in Collections:Earth Science and Engineering
Faculty of Engineering