InterRidge Fellow 2015

The InterRidge Student and Postdoctoral Fellowship Programme continues to play an important role in the careers of early career ocean scientists. There was a high number of proposals submitted again this year and we awarded three InterRidge-funded Fellowships, together with one Fellowship for students from developing countries, supported by the ISA Endowment Fund.

The recipients of this year's InterRidge Fellowship is:

Jotautas Baronas


Jotautas Baronas

Jotautas J. Baronas is a PhD student in the Earth Sciences department at the University of Southern California. He previously obtained a BS in Chemistry at Jacobs University Bremen and a MS in Earth Sciences at the University of Southern California. His PhD research is focused on developing and calibrating novel geochemical proxies to study low temperature processes, and now, with the help of the InterRidge fellowship, high temperature processes as well. In particular, his PhD work is aimed at describing a global marine budget of germanium isotopic composition. Germanium (Ge) is a trace element whose biogeochemical behavior is closely related to that of silicon (Si). Isotopic (δ74/70Ge) and elemental (Ge/Si) composition of seawater can thus reveal crucial information about silicate weathering on land, biological Si cycling in the surface ocean, and the importance of hydrothermal fluid discharge in the deep ocean. With this in mind, Jotautas is currently working on describing δ74/70Ge and Ge/Si systematics in various river watersheds worldwide, as well as major oceanic basins. However, hydrothermal vent fluids are a major source of germanium and silicon to the ocean and therefore a robust estimate of the δ74/70Ge and Ge/Si signature in various hydrothermal systems is crucial for the construction of a global marine budget. There have been some efforts to investigate Ge chemistry in mid-ocean ridge and ridge-flank systems, however, not back-arc hydrothermal systems, which tend to have very variable fluid chemistry and therefore may offer valuable insights into δ74/70Ge and Ge/Si fractionation processes.

The InterRidge Fellowship will allow Jotautas to travel to the University of Brest / IFREMER to collaborate with Dr. Olivier Rouxel in the analysis of hydrothermal fluid samples from the Manus Basin back-arc hydrothermal system. Analysis of δ74/70Ge is an arduous process that involves sample purification by column chemistry, conversion of Ge into a gaseous hydride species, and isotopic analysis on multi-collector ICP-MS. This collaboration, as enabled by the InterRidge Fellowship, will give Jotautas access to the world-class instrumentation at IFREMER and the expertise of Dr. Rouxel, who is a leading researcher of hydrothermal systems, and Ge systematics in particular. The results of this study will enhance our understanding of geochemical processes occurring in back-arc hydrothermal systems and allow for a construction of a more robust global isotopic germanium budget.