Undergraduate Research Fellowship in Arctic Erosion Studies

Project Overview:
Investigating Permafrost Riverbank Erosion through Controlled Experiments

Research Areas:
Environmental Science and Engineering, Geomorphology
In the Arctic, river systems often feature significant permafrost within their banks.

In meandering river sections, lateral erosion into the floodplain and sediment deposition in point bars modify material distribution along the channel.

Under varying thermal conditions, permafrost in riverbanks may either thaw or re-form on newly deposited sediments.

It remains uncertain whether thaw and erosion processes are primarily limited by thawing or sediment transport; additionally, the role of cohesion in frozen bank sediments and how variations in bank erodibility due to permafrost influence river migration rates and patterns are critical questions.

This research aims to elucidate the factors governing bank erosion in permafrost-affected regions and assess how sediment transport and rising Arctic temperatures affect permafrost thaw, erosion rates, and river morphology.

As global temperatures rise, Arctic communities face challenges from permafrost thaw and bank erosion, leading to hazards such as flooding and unstable ground.

These risks disproportionately impact Indigenous populations, potentially forcing relocations or imposing significant costs on infrastructure.

Understanding the mechanisms behind changing thaw and erosion rates is vital for effective hazard mitigation and forecasting.

Moreover, this study holds implications for comprehending the dynamics of sediment-borne organic carbon within Arctic river systems in a warming climate.

Position Description:
The selected student will engage in physical experiments aimed at addressing these critical knowledge gaps.

Two experimental setups are available in the Earth Surface Dynamics Laboratory:

one involving a 10-meter indoor river constructed in frozen sand, and another featuring a 7-meter river in frozen clay/mud.

The objectives of these experiments include determining the conditions under which thaw and erosion of Arctic riverbanks are constrained by thawing or sediment transport; quantifying sediment and heat transport rates; and assessing river sensitivity to warming.

The clay/mud experiments will also investigate the influence of cohesion in frozen riverbank materials.

The student will assist in setting up and conducting experiments to create channels with erodible banks, measuring sediment fluxes, collecting bank temperature data, identifying erosion and deposition zones, and analyzing resultant channel characteristics.

Daily responsibilities will encompass hands-on preparation and execution of flume experiments, data collection, and coding for data visualization and analysis.

Candidate Qualifications:
Completion of introductory courses in geology, geomorphology, and mechanical/civil or environmental engineering is required.
Experience in hands-on physical experiments and knowledge of mechanics or hydraulics is preferred.
Proficiency in Matlab or Python is essential.

Programs:
SURF (available for both Caltech and non-Caltech students)

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