Welcome to GeoUnion, the graduate student body of the Department of Earth, Environmental and Planetary Sciences. GeoUnion strives to supplement the overall graduate student experience at Rice and DEEPS. GeoUnion represents DEEPS in the overall Rice grad student community, acts as a liaison between students and faculty and organizes a number of intra- and inter-departmental events throughout the academic year.
Steamboat Geyser in Yellowstone National Park is active again!
Considered the worlds tallest active geyser, the 400 foot jet of water can be tough for the average tourist to witness, with quiescent periods lasting as long as 50 years. Yet since 2018, Steamboat has erupted more times than it has in the last half century.
Sahand Hajimirza is on the team (with lead author Dr. Mara Reed and senior author Professor Michael Manga from University of California at Berkeley) that wanted to know why.
“We know geysers need water, heat and a proper plumbing system. But we still do not know how the combination of these three factors lead to an eruption, “ says Sahand.
Stable isotope (C, N, O, and H) study of a comprehensive set of feathers from two Setophaga citrina
Deme, S., Laurence Y. Yeung, Tao Sun, and Cin-Ty A. Lee, PLoS ONE 16 (2021): e0236536.
Oxygen, hydrogen, carbon and nitrogen stable isotopes were measured on a comprehensive sampling of feathers from two spring Hooded Warblers (Setophaga citrina) in Texas to evaluate isotopic variability between feathers and during molt. Isotopic homogeneity within each bird was found across all four isotopic systems, supporting the hypothesis that molt in these neotropical migrants is fully completed on the breeding grounds. This homogeneity suggests that the isotopic composition of a single feather is may be representative of the whole songbird. However, each bird was found to have one or two outlier feathers, which could signify regrowth of lost feathers after prebasic molt.
Laurence Y. Yeung and Justin A. Hayles
Rev. Mineral. Geochem. 86 (2021) 97-137
Are current theoretical methods sufficiently accurate to benchmark oxygen triple-isotope
geochemistry? In this review and synthesis article, we first cover basic concepts and notation relevant to oxygen triple-isotope geochemistry. Second, we examine what theory predicts for oxygen triple-isotope variability in chemical processes. Third, we examine the systematic biases that may be present in theoretical approaches, with special attention paid to first-principles electronic structure calculations. Fourth, we will consider the current limits of analytical accuracy and the complications introduced by physical effects in real systems. Finally, we revisit the triple-isotope mass dependence of carbonate acid digestion as a case study of how theory and experiment can work together to improve both each other and ultimately also our understanding of a process that is vital for the emerging area of carbonate-based paleohydrology.
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