Global ETD Search
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Showing 1 to 16 of 16 for “"knickpoints"”.
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The transient response of bedrock river networks to sudden base level fall
… to study the initiation and distribution of knickpoints within fluvial networks. Field observations are derived from the Waipaoa River on the North Island of New Zealand. In the Waipaoa, 236 knickpoints distributed throughout the network define the upstream extent of a large magnitude …
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The evolution of the Congo- Kalahari Watershed: African mega-geomorphology
… divide. The creation of a geodatabase on river knickpoints, featuring geographic and geologic attributes for 18 longitudinal river profiles represented by 194 047 elevation points (19 700 km), identifies a total of 380 knickpoints, 243 of which have heights larger than 5 m. It is possible to …
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New incision rates on the Colorado River system based on cosmogenic burial dating of terraces : implications for a transient knickpoint at Lees Ferry and differential uplift of the Rocky Mountains
… profiles in both rivers are evident by numerous knickpoints and convexities. By compiling existing age constraints and applying cosmogenic burial dating techniques to previously undated bedrock strath terraces, we determine spatial and temporal patterns of incision and profile evolution over the …
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A regional study of landslide hazards and related features in the Upper Indus River Basin, northern Pakistan
… 700 km upstream of Tarbela Dam and Reservoir. Knickpoints in the channel's thalweg profile may prove useful in identifying old landslide debris dam sites because these features often create flow obstructions. To test this hypothesis, 251 knickpoints were identified and marked along the channel …
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Lithologic Controls on Bedrock Channel Morphology in the Buffalo River Basin
… age limestone, typically correspond to knickpoints arrested at the upper contact. Field and laboratory analysis suggest that limestone dissolution may be an important mechanism for knickpoint initiation in the Boone Formation.</p>
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Investigating the Effects of Lithology on Landscape Evolution Processes across Scales
… Detailed field surveys of 21 lithologic knickpoints, surrounding non-knickpoint reaches, and corresponding bedrock properties reveal three key outcomes: 1) discontinuity spacing is a stronger predictor of knickpoint occurrence, and therefore more significant in setting bedrock erodibility …
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Understanding uplift of the Ethiopian Plateau from longitudinal profile analysis of the Blue Nile drainage system
… tease out regional tectonic signals.</p> <p>244 knickpoints were examined in the tributaries, majority (>80%) of which are unassociated with lithology or geological structures. Knickpoint distribution throughout the plateau reveals three incision phases. The novel approach of correlation of …
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Holocene Periods of Aggradation and Incision, Hanson Creek, Washington
… by high magnitude floods that incised initial knickpoints, subsequently lowering base level.</p>
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Timing and pattern of valley excavation, Le Sueur River, south-central Minnesota, USA
… incision on Minnesota River tributaries as knickpoints propagated upstream from the main stem Minnesota River. As the knickpoint moved up the Le Sueur River, hundreds of terrace surfaces were formed. These terraces are strath terraces carved into glacial tills, with alluvial deposits …
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Generation of Buried Transient Landscapes and Residual Depth Anomalies
… and contain multiple knickzones and knickpoints that are systematically arranged within catchment areas. Applying the stream power law, longitudinal river profiles are inverted to calculate spatially and temporally varying uplift histories. These unique landscapes are attributed to …
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New constraints on the late Cenozoic incision history of the New River, Virginia
… bedrock that floors the river at prominent knickpoints demonstrate that the river is currently incising toward base level. However, large packages of alluvial fill and fluvial terraces cut into this fill record an incision history for the river that includes several periods of stalled …
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An investigation into the geomorphology of the Hebron Fault, Namibia, using a satellite-derived, high-resolution digital elevation model (DEM)
… river channel displacements and identifying knickpoints along river profiles. Results indicate that the scarp formed from a normal, dip-slip fault that ruptured in a single event. This scenario would imply a high slip-to-length ratio. A comparison of other SCR fault scarps in the literature …
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Evolution of transient topography on passive margins: A study of landscape disequilibrium in the southern Appalachian Mountains
… along the Plateau margin. The distribution of knickpoints, bedrock gorges, and relict surfaces in the interior of the Plateau indicate that the New River, which drains to the continental interior, is actively incising the low-relief Plateau surface due to episodic drops in landward base level. …
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The Form and Function of Headwater Streams Based on Field and Modeling Investigations in the southern Appalachian Mountains
… in bedrock resistance within a channel create knickpoints that lower stream competence and slow hilllslope erosion. Stream competence is generally higher in channels with erodable bedrock and lower in channels with resistant bedrock, but most channels could entrain the majority of the grains on …
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The relationship between active faulting and fluvial geomorphology: a case study in the Gediz Graben, Turkey.
Identifying tectonically active faults and quantifying rates of movement is a key challenge in the Earth Sciences, in addition to this the interactions between active faulting and the landscape, specifically involving the fluvial network, is a relatively new area of study. Previous work has …