Acquisition of a Stable Isotope Mass Spectrometer for Automated Carabonate Analysis: Analytical Instrumentation for Earth Science/Global Change Research

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9628080 Cole This grant provides $113,487 as one-half support of the costs of acquiring a stable isotope ratio mass spectrometer (SIRMS) with a dual inlet system and a Kiel device for automated carbonate sample introduction. The PI's research involves deciphering high resolution records of climate change indicated by variations in the carbon and oxygen isotopic signatures recorded in biogenic carbonates including corals, foraminifera and mollusc shells. The primary focus of research to be conducted utilizing this mass spectrometer will be on analyses of the del 18-O recorded in massive, scleractinian coral skeletons as high resolution indicators of variability in tropical sea surface temperatures. These corals grow rapidly and can live for periods as long as 800 years and thus offer a unique, high resolution record of climate variability over decadal to centurian time-scales and can aid our understanding of coupled ocean-atmospheric systems such as the El Ni o/Southern Oscillation that has global significance in determining patterns of precipitation and thus is relevant to worldwide agriculture and flooding hazard mitigation. To effectively and efficiently analyze the carbon and oxygen isotopic ratios recorded in biogenic carbonates at sub-monthly resolutions requires a sensitive mass spectrometer capable of analyzing samples in the 100-600 micro-gram size range with high throughput. Analyses of upwards of 10,000 samples per year including sufficient replicates so as to ensure regional fidelity can be required for century-scale records. The inclusion of a Kiel device in this acquisition will allow unassisted and sequential sample introduction of up to 74 samples, thus allowing for nighttime operations which are essential for maintaining the high throughput necessary for these high- resolution studies. ***