Integral Field Spectroscopy with Gemini: Support for IFU data in the Gemini IRAF package

We present a brief overview of facilities for Integral Field Spectroscopy at the Gemini Observatory. These include four optical and near-infrared IFUs suitable for high spatial resolution work and a suite of tasks for handling IFU data in the Gemini IRAF package. We describe the tools for data reduction that are available now or planned in the near future, helping investigators make productive use of these ground-breaking instruments. Further details on the individual IFUs, specific science applications and reduction examples are given in associated presentations by Beck et al., Carrasco et al., Trancho et al. and Winge et al.     

Uranium(VI) adsorption and surface complexation modeling onto vadose sediments from the Savannah River Site

Uranium U(VI) adsorption was measured as function of pH (3–10) on goethite, kaolinite, quartz, two binary mixtures of goethite and kaolinite, and a vadose zone sediment collected on The Department of Energy’s Savannah River Site (SRS), the clay mineral fraction of which is composed largely of kaolinite and goethite. Diffuse-layer surface complexation models were parameterized using the code PEST together with PHREEQC to fit U(VI) sorption data for the pure goethite, kaolinite, and quartz. U(VI) adsorption on kaolinite and goethite was modeled as the formation of two bidentate U(VI) complexes at mineral edge sites on a variable charge site. U(VI) adsorption on quartz was described using a one-site diffuse-layer with the formation of bidentate complex on a variable charge site. These models were used to predict U(VI) adsorption on the binary sorbent mixtures and the SRS sediment using a simple component-additivity approach. In general, the predicted adsorption edges were in good agreement with measured data, with statistically similar goodness of fit compared to that obtained for the pure mineral systems.     

Late Holocene temperature record from southwestern Australia: evidence of global warming from deep boreholes*

A ground surface temperature history for the last 500 years was created from the inversion of geophysical temperature logs in four deep (?>?1400?m) boreholes on the Blackwood Plateau in southwestern Australia. Modelled temperature changes show close agreement with ground surface temperature histories from elsewhere in the world for this period and indicate that the Blackwood Plateau has experienced a 0.4 K increase in mean temperature between the beginning of the sixteenth century and the 1980s, with more than half of the increase having taken place after 1900. The modelling indicates that the highest temperatures in the region for the last 500 years were recorded during the twentieth century, and that the current rate of temperature change of more than 0.5° K per century is higher than at any other time during this time period.