Acquisition of a high resolution, sector field, ICP-MS and laser ablation system

University Of Hawaii, Honolulu

Investigators

Abstract

EAR-0215297 Ravizza This award provides support to the University of Hawaii's School of Ocean and Earth Science and Technology (SOEST) for acquisition of a high resolution, sector field, inductively coupled plasma mass spectrometer (HR-SF-ICPMS) and laser ablation system. The mass spectrometer is a versatile instrument for trace analysis in a wide variety of natural materials including seawater, sediments and rocks. The laser ablation unit allows direct trace analysis of many solid materials, eliminating the need for time consuming and expensive chemical dissolution procedures. At SOEST this instrumentation will be used to advance research efforts in chemical oceanography, paleoceanography, geochemistry and volcanology. Analyses of trace metals in seawater will be used to better quantify the rate of supply of dust to the surface ocean and it solubility. This information is required to test current hypotheses that trace metal availability limits biological productivity in large portions of the open ocean. Trace element analyses of biogenic calcium carbonate precipitated by marine organisms will be used to improve our ability to reconstruct the history of ocean temperature changes and fluctuations in atmospheric carbon dioxide levels. Paleoceangraphic data of this sort are used to establish the magnitude and rate of climate variability prior to significant human impact. Data of this type is an essential component of efforts to discern between natural climate variability and human-induced climate perturbations. Trace element and isotope analyses of marine sediments will be performed in order to elucidate the geologic history of chemical weathering. A better understanding of chemical weathering is a necessary part of the geologic community's effort to understand those natural processes that have maintained an atmosphere capable of sustaining macroscopic life for hundreds of millions of years. Sediment geochemistry studies that document concentrations of platinum group elements in the environment will also be conducted. Available data indicated these metals are released from automobile catalytic converters and are enriched in widely distributed areas of the globe. These, and related efforts in environmental geochemistry, are part of the research community's contribution to assessing the importance of emerging human impacts on the global environment. The mass spectrometer and laser ablation system will also contribute to the research program of several volcanologists and petrologists at SOEST. These investigators use trace element data in conjunction with other data sets to understand melting in the deep earth, and the magmatic differentiation processes. These processes are responsible for producing volcanic activity at the surface of the Earth. Research efforts include studies of seafloor volcanism, explosive volcanoes in island arc settings, as well as the unique natural laboratory provided by active volcanism on the big island of Hawaii. ***