(Department of Geology and Geophysics), third-year Ph.D. student, studies the recent geological history of intermediate water circulation.Rose uses sediment cores taken from various depths in the Atlantic Ocean in order to help increase our understanding of ocean circulation over the past 20,000 years. In particular, Rose obtains down-core sediment samples, and then measures trace metals in the shells of organisms that lived in the past ocean. Cadmium concentrations in the shells of the bottom-dwelling organism H. elegans provide information about the past cadmium concentration in the water at a particular core location. Since water masses originating in the north Atlantic have different Cd signatures from those originating in the south, the variability in the cadmium concentration of H. elegans over the past 20,000 years provides insights into the variability of past ocean circulation.
In addition, Rose looks at magnesium concentrations in the shells of the bottom-dwelling organism Cibicidoides spp. and the surface-dwelling organism G. ruber. The magnesium concentration in the shells of these organisms is an indicator of the temperature of the water in which the shell formed. Therefore, by measuring magnesium in the shells of both bottom-dwelling and surface-dwelling organisms, Rose obtains information about past changes in bottom water temperature and sea surface temperature. By combining the temperature data and the cadmium-derived ocean circulation data, Rose hopes to better understand the link between ocean circulation and climate change.