Polina Tselykh (PhD Student)

Research interests:

Distribution of trace elements in the ocean

Geochemical behaviour of High field strength elements (HFSE) Zr, Nb, Hf, Ta and W in different regions of the world Ocean

Influence of regional features, e.g. anthropogenic input, hydrothermal input, oxygen minimum zone, dust input, on HFSE distribution in Oceans

Research project: Sinks, sources and processes of selected transition metals in the ocean – a contribution to the GEOTRACES program

My research focuses on the geochemical behaviour of high field-strength elements (HFSE), such as Zr, Nb, Hf, Ta, and W, in the Equatorial and Southern Pacific Ocean. I aim to investigate the influence of different environmental parameters on the distribution of these elements, including continental input from the shelf, hydrothermal input, oxygen minimum zones, and dust input. Additionally, these HFSE can serve as paleoproxies for water masses, making these elements even more interesting and important for research. The concentrations of these elements will be measured using ICP-MS.

Another aspect to consider is how HFSE are represented in different size fractions (dissolved, colloidal, particulate) in the samples and the influence of fractionation on their transport and flux in the oceans. To investigate this, I will analyse ultrafiltration and sequential filtration samples from the same stations. I will compare the distribution of trace metals in different size fractions and examine changes in response to environmental variations.

However, since the concentrations in seawater samples are extremely low (pmol kg−1), the samples will undergo pre-concentration using an offline-seaFAST system. Additionally, my work during my PhD will involve the development of methods for HFSE concentration analysis, including the offline SeaFAST pre-concentration procedure.

For this research, samples from the South Pacific and the Pacific section along the Equator, collected during GEOTRACES expeditions, specifically SO289 (GP21) and SO298 (GP11), will be analysed. Through my work, my goal is to make a substantial contribution to the GEOTRACES mission. This mission aims to identify processes and accurately quantify fluxes that govern the distributions of crucial trace elements and isotopes in the ocean. Additionally, I plan to assess how these distributions respond to changing environmental conditions.