Serena’s first paper was just published in Geology! She measured the oxygen isotopic composition of modern and fossil gastropod shells of the genus Turritella at high (subannual) resolution. In tropical settings, temperature doesn’t vary too much throughout the year, so the large seasonal variations in d18Ocarbonate were therefore attributable to changes in d18Oseawater, which she linked to on-shore precipitation. This indicated that there was a high seasonality of precipitation at the sample site (Guajira Peninsula, Colombia), which is today an extremely arid environment. She suggested that the Intertropical Convergence Zone (ICTZ), a band of high precipiation, could have extended to a more northerly position during the warm Miocene and been the source of this increased precipitation seasonality.
Congrats Serena on your first paper!