Details of Award
NERC Reference : NE/C510416/1
Using the glacioisostatic uplift of N Britain to assess the controls on knickpoint recession in bedrock river channels.
Grant Award
- Principal Investigator:
- Professor P Bishop, University of Glasgow, School of Geographical & Earth Sciences
- Co-Investigator:
- Professor T Hoey, Brunel University London, Civil and Environmental Engineering
- Grant held at:
- University of Glasgow, School of Geographical & Earth Sciences
- Science Area:
- Earth
- Overall Classification:
- Earth
- ENRIs:
- None
- Science Topics:
- Earth Surface Processes
- Sediment/Sedimentary Processes
- Tectonic Processes
- Quaternary Science
- Abstract:
- Bedrock river channels are the 'skeleton' of the landscape They provide the reference (base) level to which erosional processes operate and they act as the pathway for the removal of sediment from the landscape to sedimentary basins. Bedrock channel erosion is therefore a key to understanding landscape history and sediment flux, but the rates and processes of bedrock river response remain poorly understood in detail. We know in a general way that when relative sealevel falls (as a result, for example, of uplift of the land surface), river channels adjust to the lower sealevel by eroding their beds A steeper reach (knickpoint) develops close to the shore and begins to migrate inland. Key factors controlling the rate of this migration are the river's water discharge, its local bed slope and the resistance of the rocks being eroded. Knickpoints may retain their full height as they migrate, or they may gradually become less steep and disappear as they move inland. Here, bedrock channels on the east and west coasts of Scotland will be used to quantify the relationship between knickpoint migration rate, discharge and slope. These sites are well-suited to this work as uplifted shorelines are clearly identifiable and well-preserved, and are overlain in places by sedimentary (fluvioglacial) deposits suitable for dating. Marked differences in rainfall (and thus river discharge) and rock-type between the east and west coast sites will allow direct assessment of these specific controls over knickpoint behaviour The analysis requires accurate dating of the initiation of the knickpoints (timing of relative sea-level change), for which we will use. (1) optically-stimulated luminescence dating of deposits that overlie uplifted shorelines; (2) cosmogenic isotope concentrations to determine the exposure ages of former bedrock channel surfaces (straths). Both techniques will be carried out in the world-leading laboratories at the Scottish Universities Environmental Research Centre. The ages will be used to derive rates of knickpoint migration that will then be statistically related to discharge and river bed slope. These statistical relationships will be assessed in a numerical model of bedrock river incision, taking full account of modelling uncertainties, to assess the implications for the rates and styles of knickpoint evolution of the field results. The project will provide results that are of interest to geoscience researchers and industry, including the British Geological Survey who will directly utilise the data from this project. Most importantly, the results will help us to understand more fully how the rivers that are eroding the Earth's surface respond to uplift and how much sediment is transported to sedimentary basins as a result.
- NERC Reference:
- NE/C510416/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £115,503
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £62,266 | £11,073 | £13,523 | £28,642 |
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