IAP-24-035

Assessing the environmental risk of contaminant accumulation and release from retreating glaciers

Glaciers act as reservoirs for contaminants that fall onto their surface through processes including atmospheric deposition, mass movements, and anthropogenic activities (Beard et al., 2022; Clason et al., 2015), and can accumulate and store these materials for decades or longer. Contaminants are not only stored by glaciers, but are also concentrated through their interactions with snow, ice, meltwater, and glacial sediments. Cryoconite, an organic-rich material commonly found on the surface of glaciers, has also been demonstrated to have a unique ability to efficiently accumulate some contaminants (e.g. Owens et al., 2019; Clason et al, 2021). As glaciers melt in response to a warming climate the materials they contain are released and transported downstream, such that legacy contaminants can be remobilized and pose a potential threat for local water quality, ecosystems, and communities.

This project will quantify fallout radionuclides (FRNs) and potentially toxic elements (PTEs) within the Hintereisferner glacier catchment in the Austrian Alps, to improve our understanding of how contaminants are accumulated and mobilised within mountain glacier settings. The project will also assess future risk from contaminant release for the downstream environment and communities, providing a novel, interdisciplinary understanding of contaminant release in glacier catchments. While considerable research efforts have been made to quantify the consequences of glacier retreat for freshwater discharge and sea level, research into what this means for the legacy materials accumulated within glaciers, and downstream consequences, is in its infancy. To address this research gap, this project proposes three objectives:

1. To quantify FRNs and PTEs in cryoconite and sediments on and downstream of Hintereisferner glacier.

2. To assess the risk from release of legacy contaminants under future glacier melt scenarios.

3. To engage with local stakeholders to understand current perceptions of environmental risk and communicate risk from legacy contaminant release.

The Hintereisferner glacier is a ‘natural laboratory’ set within the Austrian Alps. It has been monitored by the University of Innsbruck since 1957, and the whole catchment has a comprehensive hydro-meteorological monitoring network that is part of the International Network for Alpine Research Catchment Hydrology and the global Long Term Ecosystem Research network. The successful candidate will conduct fieldwork to sample cryoconite and proglacial sediments in the Hintereisferner catchment, and apply geochemical techniques to identify and quantify contaminants including FRNs and PTEs. In addition to analysing the levels of contaminants present, and their mobility within the glacier and its downstream environment, this project will apply existing computer models to simulate glacier melt and contaminant mass flux to predict the release of stored contaminants under future warming scenarios. The student will also engage local stakeholders to understand current perception and prioritisation of environmental risk, and communicate the findings of their own research as it develops.

The methods can be split into four distinct but interlinked packages of work:

1: Geochemical analysis of contaminants in cryoconite and sediment samples.

• Sampling of cryoconite, sediments, and organic materials on the glacier surface and within the proglacial environment.
• Application of gamma spectrometry and wavelength dispersive x-ray fluorescence to quantify contaminant levels across the catchment.
• Comparison of contaminant levels identified in materials from the proglacial environment to probable effect levels.

2: Identification of processes and pathways governing accumulation and transport of contaminants.

• Create/identify a test cryoconite hole on Hintereisferner in year 1, with observation of cryoconite evolution and repeat sampling in year 2 to quantify contaminant accumulation.
• Application of sediment fingerprinting to assess the primary sources and pathways for contaminant transport within the catchment. External collaborator Professor Will Blake is an expert in sediment dynamics and will contribute to training for this method.

3: Modelling of contaminant release under future scenarios of glacier melt.

• Projections of glacier melt using existing future climate forcings and surface meltwater production modelling tools that are available through partner projects at the University of Innsbruck.
• Contaminant mass flux simulation under current and future climate conditions.
• External collaborator Dr Lindsey Nicholson will help in the set-up of modelling experiments, drawing upon extensive experience in glacier modelling and the climate of this region.

4: Assessment and communication of environmental risk with local stakeholders.

• Risk mapping to explore current perception and prioritisation of environmental risks and pressures with local stakeholders.
• Design of materials to communicate research findings, based on stakeholder-identified preference, including future contaminant release scenarios.
• Communication of possible risk (if any) identified in work packages 1 to 3.

Year 1

• Literature review and production of a PhD work plan.
• Design of fieldwork sampling strategy.
• First field season on Hintereisferner.
• Initial conversations with local stakeholders.
• Training in geochemical analysis techniques using samples collected in year 1.

Year 2

• Second field season on Hintereisferner.
• Risk mapping with local stakeholders.
• Geochemical analysis of samples from year 2.
• Begin writing of thesis and papers.

Year 3

• Modelling contaminant release under future climate scenarios.
• Communication of project outcomes with local stakeholders.
• Continue writing of thesis and papers.

Year 3.5

• Completion of thesis writing.
• Thesis submission and preparation / submission of papers.

This project is suitable for students who have studied subjects such as Geography or Environmental Science, and the successful applicant will gain a broad interdisciplinary skillset, including training in geochemical analytical techniques, glacier field research, engaging with stakeholders to communicate and understand risk, and in the application of existing computer models. The supervisory team, who have expertise in glacial hydrology, environmental and health risk, contaminants in glacial environments, glacier-climate interactions, and catchment science, will oversee project-specific training, ensuring that the candidate develops the skills required to address the objectives of this project.

The student will be supported in the development of transferable skills, fostering professional development and employability post-PhD. The student will present their research nationally and internationally, and will be encouraged to drive the direction of their research throughout the project, contributing to their development as an independent researcher.