Journal ArticleDOI
Landscape response to tectonic forcing: Digital elevation model analysis of stream profiles in the Mendocino triple junction region, northern California
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In this article, the authors evaluate and calibrate the shear stress (or similar unit stream-power) bedrock-incision model by studying stream profiles in a tectonically active mountain range.Abstract:
The topographic evolution of orogens is fundamentally dictated by rates and patterns of bedrock-channel incision. Quantitative field assessments of process-based laws are needed to accurately describe landscape uplift and denudation in response to tectonics and climate. We evaluate and calibrate the shear stress (or similar unit stream-power) bedrock-incision model by studying stream profiles in a tectonically active mountain range. Previous work on emergent marine terraces in the Mendocino triple junction region of northern California provides spatial and temporal control on rock-uplift rates. Digital elevation models and field data are used to quantify differences in landscape morphology associated with along-strike northwest to southeast changes in tectonic and climatic conditions. Analysis of longitudinal profiles supports the hypothesis that the study-area channels are in equilibrium with current uplift and climatic conditions, consistent with theoretical calculations of system response time based on the shear-stress model. Within uncertainty, the profile concavity (𝛉) of the trunk streams is constant throughout the study area (𝛉 ≈ 0.43), as predicted by the model. Channel steepness correlates with uplift rate. These data help constrain the two key unknown model parameters, the coefficient of erosion ( K ) and the exponent associated with channel gradient ( n ). This analysis shows that K cannot be treated as a constant throughout the study area, despite generally homogeneous substrate properties. For a reasonable range of slope-exponent values ( n ), best-fit values of K are positively correlated with uplift rate. This correlation has important implications for landscape-evolution models and likely reflects dynamic adjustment of K to tectonic changes, due to variations in orographic precipitation, and perhaps channel width, sediment load, and frequency of debris flows. The apparent variation in K makes a unique value of n impossible to constrain with present data.read more
Citations
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Journal ArticleDOI
Distribution, Sediment Source, and Coastal Erosion of Fan-Delta Systems on Isla Cerralvo (Lower Gulf of California, Mexico)
TL;DR: Backus et al. as mentioned in this paper found that Isla Cerralvo's shelf is largely devoid of biogenic carbonates, especially rhodolith beds, which are found in abundance elsewhere within the region.
Journal ArticleDOI
Post-rift geomorphological evolution of a passive continental margin (Paraíba region, northeastern Brazil): Insights from river profile and drainage divide analysis
Fabio Corrêa Alves,Martin Stokes,Sarah J. Boulton,Dilce de Fátima Rossetti,Márcio de Morisson Valeriano +4 more
TL;DR: In this article , a digital elevation model (DEM) was used to provide long river profiles based on the χ approach, normalized channel steepness index (k sn ), and drainage divide analysis.
Dissertation
Controls on fluvial networks in upland landscapes: from hillslopes to floodplains
TL;DR: In this paper, the authors developed and tested new algorithms for objective feature extraction from lidar-derived digital elevation models (DEMs) for identifying the upstream extent of channel processes by identifying scaling breaks in river long profiles.
Journal ArticleDOI
The Concavity of Submarine Canyon Longitudinal Profiles
TL;DR: In this article, the authors used existing geomorphological, tectonic and climatic datasets to measure the long profiles and quantify the concavities of 377 modern submarine canyons and found that the dominant control on submarine canyon concavity is tectonics, with forearcs and tectonically active margins hosting the least concaveup profiles.
Journal ArticleDOI
Millennial-scale erosion patterns of the northern Qinling Mountains, Central China: Implications for topographical evolution
TL;DR: Wang et al. as mentioned in this paper investigated the topographic evolution of the northern Qinling Mountains over millennial timescales and explored the major controlling factors of relief development, and calculated 10Be-derived catchment-averaged erosion rates.
References
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Journal ArticleDOI
Tectonic forcing of late Cenozoic climate
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Journal ArticleDOI
Channel-reach morphology in mountain drainage basins
TL;DR: In this article, a classification of channel-reach morphology in mountain drainage basins synthesizes stream morphologies into seven distinct reach types: colluvial, bedrock, and five alluvial channel types (cascade, step pool, plane bed, pool rime and dune ripple).
Journal ArticleDOI
Magnitude and Frequency of Forces in Geomorphic Processes
M. Gordon Wolman,John P. Miller +1 more
TL;DR: The relative importance in geomorphic processes of extreme or catastrophic events and more frequent events of smaller magnitude can be measured in terms of the relative amounts of "work" done on the landscape and the formation of specific features of the landscape as discussed by the authors.
Journal ArticleDOI
Dynamics of the stream‐power river incision model: Implications for height limits of mountain ranges, landscape response timescales, and research needs
TL;DR: In this article, the authors explore the stream power erosion model in an effort to elucidate its consequences in terms of large-scale topographic (fluvial) relief and its sensitivity to tectonic and climatic forcing.