Recent gas flux measurements have shown that Strombolian explosions are often followed by periods of elevated flux, or "gas codas," with durations of order a minute. Here we present UV camera data from 200 events recorded at Stromboli volcano to constrain the nature of these codas for the first time, providing estimates for combined explosion plus coda SO masses of ≈18-225 kg. Numerical simulations of gas slug ascent show that substantial proportions of the initial gas mass can be distributed into a train of "daughter bubbles" released from the base of the slug, which we suggest, generate the codas, on bursting at the surface. This process could also cause transitioning of slugs into cap bubbles, significantly reducing explosivity. This study is the first attempt to combine high temporal resolution gas flux data with numerical simulations of conduit gas flow to investigate volcanic degassing dynamics.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4950127 | PMC |
http://dx.doi.org/10.1002/2016GL069001 | DOI Listing |
Water Res
January 2025
Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
Riverine NO and N fluxes, key components of the global nitrogen budget, are known to be influenced by river size (often represented by average river width), yet the specific mechanisms behind these effects remain unclear. This study examined how environmental and microbial factors influenced sediment NO and N fluxes across rivers with varying widths (2.8 to 2,000 m) in China.
View Article and Find Full Text PDFSci Total Environ
January 2025
Research Centre of Ecology & Environment for Coastal Area and Deep Sea, Guangdong University of Technology, Guangzhou 510006, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China; Guangdong Basic Research Center of Excellence for Ecological Security and Green Development, Guangdong University of Technology, Guangzhou 510006, China. Electronic address:
Methane leaking from the deep seabed is a primary source of carbon and energy for various microorganisms, sustaining the evolution and productivity of cold seep ecosystems. However, the dynamics of methane hydrate formation under methane seepage conditions and potential impacts on the evolution of cold seep ecosystems remain unclear. This study investigated the dynamic formation characteristics of gas hydrates within cold seep sediments by simulating the methane leakage process.
View Article and Find Full Text PDFJ Mol Model
January 2025
Laboratorio de Química Teórica Computacional (QTC), Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, 7820436, Santiago de Chile, Chile.
Context: Dopamine -monooxygenase (D M) is an essential enzyme in the organism that regioselectively converts dopamine into R-norepinephrine, the key step of the reaction, studied in this paper, is a hydrogen atom transfer (HAT) from dopamine to a superoxo complex on D M, forming a hydroperoxo intermediate and dopamine radical. It was found that the formation of a hydrogen bond between dopamine and the D M catalyst strengthens the substrate-enzyme interaction and facilitates the HAT which takes place selectively to give the desired enantiomeric form of the product. Six reactions leading to the hydroperoxo intermediate were analyzed in detail using theoretical and computational tools in order to identify the most probable reaction mechanism.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Department of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey 08544, USA.
We present a scalable protocol for measuring full counting statistics (FCS) in experiments or tensor-network simulations. In this method, an ancilla in the middle of the system acts as a turnstile, with its phase keeping track of the time-integrated particle flux. Unlike quantum gas microscopy, the turnstile protocol faithfully captures FCS starting from number-indefinite initial states or in the presence of noisy dynamics.
View Article and Find Full Text PDFSci Rep
January 2025
Key Laboratory of Songliao Aquatic Environment, Ministry of Education, Jilin Jianzhu University, No.5088 Xincheng Road, Changchun, 130118, Jilin Province, China.
NH is the most important alkaline gas in the atmosphere and functions as a precursor to secondary ammonium salts. Therefore, identifying its sources and quantifying its emissions is imperative. NH represents a principal component of atmospheric particulate pollutants.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!