Dr. Ryu Uemura is currently an Associate Professor at the Department of Chemistry, Biology and Marine Science, University of the Ryukyus (Okinawa, Japan). He earned his Ph.D. degree in 2005 from the Tokyo Institute of Technology. After that, he first worked in the National Institute of Polar Research in Japan, and measured isotopes of water vapour in the Southern Ocean. In 2008, he moved to Laboratoire des Sciences du Climat et de l’Environnement (LSCE/IPSL), CEA-CNRS in France and continued his work on isotope modelling to reconstruct temperature change in the Antarctic. He then joined University of the Ryukyus in 2010 as a faculty member, and has been there since then.
The oxygen isotope composition (δ18O) of speleothem is widely used as paleoclimate proxy. Interpretation of the δ18O value is not straightforward because it is controlled by two factors; δ18O of dripwater and temperature at calcite formation. The δ18O of speleothem fluid-inclusions, paleo-dripwaters, will provide an important constraint for the unknown quantity. Although its paleoclimatic applications have been hampered by technical difficulties, recent developments of a new laser-based isotope ratio mass spectrometer have opened a new door of fluid inclusions analysis (e.g., Affolter et al., 2014; Arienzo et al., 2013; Uemura et al., 2016). I will show recent developments of fluid inclusion measurement system based using Cavity Ring down Spectroscopy (CRDS), and results from speleothem in Okinawa, Japan.