Arrivals of P waves from a recent event at the Nevada Test Site, recorded at a distance of 15.3 degrees , passed beneath the Yellowstone caldera at depths of 200 and 400 kilometers. The travel time anomalies are modeled by a vertical cylindrical structure with a high-velocity core and a low-velocity collar as compared with the more normal mantle. The velocity structure and vertical extent of this feature are consistent with a chemical mantle plume beneath the Yellowstone caldera.
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http://dx.doi.org/10.1126/science.193.4259.1237 | DOI Listing |
Bull Environ Contam Toxicol
January 2025
School of Mathematics and Physics, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu, 215123, China.
This study focuses on the composition and sources of dissolved organic matter (DOM) in the Fancun Reservoir, located in Ningguo City, Anhui Province, China. The investigation was conducted by analyzing the spectral characteristics of DOM using UV-Vis absorption spectra and fluorescence spectroscopy. The humic substances were dominated by fulvic acid, with an average DOM concentration of 30.
View Article and Find Full Text PDFNat Commun
January 2025
Cnr-Istituto di Geologia Ambientale e Geoingegneria, Roma, Italy.
Volatiles (CO, HO) play a fundamental role in mantle melting beneath ocean spreading centers, but what role they play during the melt migration remains unknown. Using seismological data recorded by ocean-bottom seismometers, here we report the presence of deep earthquakes at 10-20 km depth in the mantle along the Mid-Atlantic Ridge axis, much below the brittle-ductile boundary. Syntheses of regional basaltic rock samples and their geochemical analyses indicate the presence of an abnormally high quantity of CO (~0.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Cosmochemistry and Isotope Signatures Group Nuclear and Chemical Sciences Division Lawrence Livermore National Laboratory, Livermore, CA 94550.
The radiogenic isotopic compositions of basaltic Martian meteorites (shergottites) and clinopyroxene/olivine cumulate meteorites (nakhlite/chassignites) are used to define the global evolution of Mars. However, the two main groups of meteorites demonstrate that their sources underwent divergent styles of magmatic evolution. The shergottites portray a planet that differentiated ~4.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Consortium on Health, Environment, Education, and Research (CHEER), The Education University of Hong Kong, Tai Po, Hong Kong. Electronic address:
Lead (Pb), a highly toxic heavy metal, poses a significant global health risk, particularly to children. Widely used in paint manufacturing for its remarkable corrosion-resistance properties Pb exposure has been linked to severe health issues, including reduced neurotransmitter levels, organ damage, potentially leading to death in extreme cases. Children Are particularly vulnerable, with Pb toxicity primarily affecting the brain, reproductive, kidneys, and cardiovascular systems.
View Article and Find Full Text PDFJ Synchrotron Radiat
January 2025
Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 3050801, Japan.
X-ray spectromicroscopy is extensively utilized for nondestructive mapping of chemical states in materials. However, understanding and analyzing the geometric and topological aspects of such data pose challenges due to their representation in 4D space, encompassing (x, y, z) coordinates along with the energy (E) axis and often extending to 5D space with the inclusion of time (t) or reaction degree. In this study, we addressed this challenge by developing a new approach and introducing a device named `4D-XASView', specifically designed for visualizing X-ray absorption fine structures (XAFS) data in 4D (comprising 3D space and energy), through a multi-projection system, within the virtual reality (VR) environment.
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