DETROIT — From the middle of the country, a Wayne State University researcher is working to advance understanding of the movement of chemical compounds through the world’s oceans.
Mark Baskaran, Ph.D., professor of geology in the College of Liberal Arts and Sciences, has received a three-year, $190,000 grant from the National Science Foundation for a project that will follow the pathways and cycling of two trace elements in the Pacific Ocean from Peru to Tahiti.
Titled “Geotraces — 210Po and 210Pb distribution at Eastern Pacific Interface Regimes,” the project will examine levels of polonium (Po) and lead (Pb) isotopes in water samples from Peru to Tahiti to investigate how much carbon is exported from the upper 100 meters of ocean water to deeper waters, and how hydrothermal waters released from the bottom of the ocean affect the removal of polonium and lead. While some of the key trace elements and isotopes (TEIs) to be measured during the sampling expedition have been induced by humans, others are the result of radioactive decay of naturally occurring uranium.
During a two-month cruise beginning in October 2013, Baskaran and WSU student John Niedermiller will collect thousands of liters of water samples from up to 5,000-meter depths for polonium and lead analysis in various types of waters, including those with high biological activity, those with low oxygen, and hydrothermal plumes (areas of warmer water). Such plumes can affect a number of biological processes, including large areas of algae bloom.
Baskaran’s work is part of the Geotraces project, which has been funded by the NSF since its official inception in 2008, although the research groups involved started working together in 2004. Geotraces brings together scientists from some 30 countries to study how recent environmental changes — especially those resulting from increased industrial and commercial activity in the last 200 years — have affected distribution of key TEIs and chemical processes that take place in the ocean.
“The surface of the earth and the environment are undergoing tremendous changes,” Baskaran said. “Water masses move from one ocean to another. By using key TEIs, we can study the processes that control these chemical species.”
Geotraces defines key TEIs as micronutrients essential to life in the ocean; tracers of modern processes in oceans; substances significantly perturbed by human activities; and proxies that are usable to reconstruct the past.
Based on his previous research with polonium and lead isotopes, Baskaran believes samples from the selected area will prove useful in tracking changes that have occurred. His team’s data will be added to that of researchers studying other TEIs in the same samples to provide the best possible assessment of what has occurred and when, especially within the past century.
Findings of all Geotraces researchers will be compared and integrated with data gathered from the Geochemical Ocean Section Study, funded by the NSF and conducted in the 1970s. GEOSECS was designed to collect information on chemical and biological processes taking place in the world’s oceans. Scientists plan to study all major ocean basins over the next decade.
Geotraces researchers will combine their findings with those of GEOSECS in order to create a more complete understanding of such processes. One example, Baskaran said, is that by learning more about the role of micronutrients in causing things like large algal blooms, researchers can determine whether the blooms can be minimized.
“Understanding and predicting are the goals of our work and that of other Geotraces researchers,” he said. “Once we have a really good handle on what processes are taking place, prediction becomes much easier.”
The National Science Foundation grant number for Baskaran’s study is OCE-1237059.