Although gas exsolution is a major driving force behind explosive volcanic eruptions, viscosity is critical in controlling the escape of bubbles and switching between explosive and effusive behavior. Temperature and composition control melt viscosity, but crystallization above a critical volume (>30 volume %) can lock up the magma, triggering an explosion. Here, we present an alternative to this well-established paradigm by showing how an unexpectedly small volume of nano-sized crystals can cause a disproportionate increase in magma viscosity. Our in situ observations on a basaltic melt, rheological measurements in an analog system, and modeling demonstrate how just a few volume % of nanolites results in a marked increase in viscosity above the critical value needed for explosive fragmentation, even for a low-viscosity melt. Images of nanolites from low-viscosity explosive eruptions and an experimentally produced basaltic pumice show syn-eruptive growth, possibly nucleating a high bubble number density.
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http://dx.doi.org/10.1126/sciadv.abb0413 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Earth Sciences, University of Oregon, Eugene, OR 97403.
Volcanic provinces are among the most active but least well understood landscapes on Earth. Here, we show that the central Cascade arc, USA, exhibits systematic spatial covariation of topography and hydrology that are linked to aging volcanic bedrock, suggesting systematic controls on landscape evolution. At the Cascade crest, a locus of Quaternary volcanism, water circulates deeply through the upper [Formula: see text]1 km of crust but transitions to shallow and dominantly horizontal flow as rocks age away from the arc front.
View Article and Find Full Text PDFPLoS One
January 2025
Business School, Hanyang University, Seoul, Korea.
China's island tourism is still in the exploratory stage, and the carbon emissions due to island tourism development are still prominent. This study assesses the development of low-carbon tourism on Changdao Island in China. We constructed an evaluation model for low-carbon tourism on islands based on the driver-pressure-state-impact-response model, and the Entropy Weight Method-Analytical Hierarchy Process Method was combined with the weighting method to determine the index weights of ench evaluation-indicator.
View Article and Find Full Text PDFMicrosc Microanal
January 2025
Instrumental Analysis Center, Dalian University of Technology, No.2 Linggong Road, Ganjingzi District, Dalian, Liaoning Province 116024, China.
A self-opening transfer shuttle has been designed and fabricated for the transfer of air-sensitive samples to scanning electron microscopy (SEM). Delayed push out of an airtight sample cabin sealed inside the shuttle allows the protection of the sample from air exposure during the pumping of SEM chamber. A compressed spring is employed to automatically drive the push out of the cabin.
View Article and Find Full Text PDFBio Protoc
January 2025
Laboratoire Interdisciplinaire de Physique (LIPhy), Université Grenoble Alpes, CNRS, Grenoble, France.
Cell-generated forces play a critical role in driving and regulating complex biological processes, such as cell migration and division and cell and tissue morphogenesis in development and disease. Traction force microscopy (TFM) is an established technique developed in the field of mechanobiology used to quantify cellular forces exerted on soft substrates and internal mechanical tissue stresses. TFM measures cell-generated traction forces in 2D or 3D environments with varying mechanical and biochemical properties.
View Article and Find Full Text PDFNPJ Clim Atmos Sci
January 2025
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN USA.
Severe convective storms and tornadoes rank among nature's most hazardous phenomena, inflicting significant property damage and casualties. Near-surface weather conditions are closely governed by large-scale synoptic patterns. It is crucial to delve into the involved multiscale associations to understand tornado potential in response to climate change.
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