Project 3. Quantifying the impact of volcanic ash particulates on the environment

Primary Employer: Durham University, Department of Earth Sciences, Durham, UK

PhD Programme: Durham University/University of Iceland (3 years)

Magmatic gasses condense onto the surface of ash particles during volcanic eruptions. As the particles react with atmospheric air and water vapour, the condensed gasses form sulphuric and halogen acids and the ash surfaces dissolve. The acid leaches cations from the bulk ash and secondary minerals may precipitate as a thin coating. This coating is highly water soluble, leading to rapid dispersal of potentially harmful elements and or nutrients into the enviroment upon contact with rainfall or surface waters. Landsvirkjun Power have a number of reservoirs, on rivers in the vicinity of Mt Hekla, Iceland. If these reservoirs are loaded with volcanic ash from Hekla during future eruptions, it will potentially harm the turbines in power ploants down stream from the reservoirs, and pollute the rivers. We have sampled pristine volcanic ash samples from Icelandic explosive eruptions since 2000; Hekla 2000, Grímsvötn 2004, and 2011, and Eyjafjallajökull 2010. These samples provide a unique opportunity to study the nature of the surface coatings of the ash, down to molecular level and the isotope composition of the metal salts forming the coating.

The aim of this project is to determine the isotope composition of these surface salts and the bulk volcanic ash, and for the stable isotopes the fractionation that occurs when these salts first dissolve first in the surface environment. This will be achieved first, through controlled dissolution experiments of the ash and second, the study of river water samples taken during some of the eruptions noted above. This will involve, in particular the measurement of Li isotopes (which serve as tracers of chemical weathering processes. Fe, Si and Mg (which are additionally sensitive to bio-utilization, and the highly siderophile elements (HSEs: Os, Ir, Ru, Rh, Pt, Pd and Re). These data will allow us to develop tracers with which to quantify the impact of volcanic ash on the surface environment, and on rivers and material delivered to the oceans.

The project will provide a broad experience in field, experimental and isotope measurement techniques including (i) field sampling of waters and ash in Iceland; (ii) dissolution experiments at the University of Iceland in reykjavik; (iii) measurement of stable isotopes of Li, Mg, Si and Mo and HSE abundances using state of the art clean laboratory and mass spectrometry facilities at Durham. (iii) Modeling of element transport rates in natural waters. The ESR will be based at Durham University, Landsvirkjun, and Univeristy of Iceland in Reykjavík as part of their PhD programme (and jointly registered at Durham and the University of Iceland) as part of a joint agreement between the Landsvirkjun and Durham. We envisage strong collaboration with other partners of the MetTrans network, where for example isotope measurements may be undertaken at Durham, Oxford and Toulouse. The project supervisors willl be Sigurður R Gíslason (Reykjavik), Kevin W Burton, Helen M Williams and Dave Selby (Durham).

Employment and eligibility. The PhD candidate will be employed for three years and will spend half of that time in Durham and the other in Reykjavík, at the University of Iceland. Academic requirements: Applicants should hold a degree in Earth Sciences, Environmental Sciences, Chemistry, or other relevant field. Details regarding requirements for applying to the PhD program at the Department of Geological Sciences can be found at Durham’s web site.

Network requirements: At the time of recruitment by the host organisation, applicants must be in the first four years (full-time equivalent) of their research careers (since the time of undergraduate degree or equivalent). At the time of recruitment by the host organisation, applicants must not have resided or carried out their main activity (work, studies, etc) in the country of their host organisation for more than 12 months in the last 3 years.

For further information regarding the position or the MetTrans Network, send an email to Kevin Burton at University of Durham

Application. The application must be in English and include a cover letter, curriculum vitae, certificates of examination results according to the requirements listed at the website above, and two reference letters. It should be sent to Kevin Burton. The deadline for the first round of applications is March 30, 2012.

Final applications by the selected candidate is required in electronic format (https://ugla.hi.is/umsoknir/index.php) and should be sent after the decision by the selection committee, with a copy to Hafdís Eyjólfsdóttir, project manager of graduate studies, tel: +354 525 4473, e-mail: hafdisey@hi.is.