Polina Tselykh

Sinks, sources, and processes of selected transition metals in the Equatorial and Southern Pacific Ocean – a contribution to the GEOTRACES program

My research focuses on the geochemical behavior 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 analyze 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 SO289 (GP21) and SO298 (GP11), will be analyzed. Through my work, I aim to make a significant contribution to the GEOTRACES mission, which seeks to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean. I also aim to establish the sensitivity of these distributions to changing environmental conditions.