METU-IMS SCIENTIFIC WEBINAR SERIES
Date: 21 April 2021
Time: 14:00 (GMT+3)
Speaker: Dr. Nazik Öğretmen
Title: Foraminifers in Paleoclimate Studies
Foraminifers in Paleoclimate Studies
Foraminifers are single-celled marine organisms that precipitate their shells from the ambient seawater encoding the chemical composition of the seawater within their shells (tests) and are present in the world oceans since the Permo-Carboniferous (~300 Million-years-ago). Therefore, they are archives for paleoclimate studies. Some foraminifers float in the water in various depths and are called planktic foraminifers, whereas some of them live in or on the seafloor sediment and are called benthic foraminifers. They mainly have calcium carbonate tests and bear significant proxies for climate studies. Some of these proxies are ice volume/salinity indicator stable oxygen and oxygenation indicator carbon isotopes, and Mg/Ca of the test for paleotemperature reconstructions. For example, stable oxygen and carbon isotopes, and Mg/Ca-derived paleotemperatures from benthic and planktic foraminifers collected from the deep Caribbean Sea sediment cores revealed the closure of the Caribbean Seaway as the connection between the Caribbean Sea and the Pacific Ocean resulted in the Pliocene warming from 5.2 Ma until 2.7 Ma. The closure of the Central American Seaway regulated the ocean current triggering the onset of the Northern Hemisphere Glaciation at 2.7 Ma eventually.
Short Biography
Nazik Öğretmen graduated from the Istanbul Technical University, Geological Engineering Department in 2011. She completed her MSc studies at the Eurasia Institute of Earth Sciences, Climate and Sea Sciences Research Group in 2012. She earned her PhD degree from the Roma Tre University (Italy), Earth Sciences Department on micropaleontology and biostratigraphy as a Marie Curie Fellow in 2017. She is a micropaleontologist with expertise in smaller benthic and planktic foraminifers, biostratigraphy, and paleoclimate. For paleoclimate studies, she applies modern analytical techniques commonly used in climate geochemistry, such as trace element analyses.
She is a postdoctoral fellow at the Max Planck Institute for Chemistry, Climate Geochemistry Department, Micropaleontology Research Group since 2019. Her research is paleoclimate reconstruction of the Plio-Pleistocene Caribbean Sea applying trace element analyses on benthic and planktic foraminifer tests.
