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Landscape response to tectonic forcing: Digital elevation model analysis of stream profiles in the Mendocino triple junction region, northern California

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TLDR
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.

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Dissertation

Modélisation expérimentale de la dynamique long-terme des reliefs en réponse aux forçages climatiques et tectoniques

TL;DR: In this article, the authors present the results of a large-scale experiment on reliefs in the piedmont nord-pyreneen and show that the relationship between the water-to-rock ratio (WTR) and the number of chutes de pluviometres of a chute is a function of taux de surrection.
Journal ArticleDOI

Evaluation of geomorphic expressions of bedrock Channels in the Western Ghats of southern Kerala, India, through quantitative analysis

TL;DR: In this paper, the authors quantitatively characterized geomorphic expressions embedded within the bedrock channels, originating from the southernmost part of the Western Ghats, India, using digital elevation models and geographical information system (GIS) tools.
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Evolution of fluviokarst canyons in response to the Quaternary tectonic uplift of the Apulia Carbonate Platform (southern Italy): Insights from morphometric analysis of drainage basins

TL;DR: The evolution of fluviokarst landscapes results from the interplay of karst and fluvial processes, all driven by rock uplift or base level fall as mentioned in this paper.
Journal ArticleDOI

Pothole: a unique geomorphological feature from the bedrocks of Ghaghghar River, Son valley, India

TL;DR: In this paper, the occurrence of pothole features and the processes of their development on the bedrocks of Ghaghghar River, Son valley, India were reported for the first time.
Journal ArticleDOI

Erosion of coastal drainages in the Mendocino Triple Junction region (MTJ), northern California

TL;DR: In this article, the Mendocino Triple Junction (MTJ) region in northern California is an archetype for studying landscape response to varying rock uplift rates as they increase toward the triple junction, and the authors report 10Be and 26Al-derived erosion rates calculated from isotope concentrations in detrital, fluvial sediment from coastal drainage basins.
References
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Book

Water in environmental planning

TL;DR: A comprehensive review of the current literature associated with water resources can be found in this paper, but perhaps more importantly can also be used as an introductory working document in dealing with particular environmental problems.
Journal ArticleDOI

Tectonic forcing of late Cenozoic climate

TL;DR: In particular, tectonically driven increases in chemical weathering may have resulted in a decrease of atmospheric C02 concentration over the past 40 Myr as discussed by the authors. But this was not shown to be the case for the uplift of the Tibetan plateau and positive feedbacks initiated by this event.
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

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.
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