| 1. |
- Aartsen, M. G., et al.
(författare)
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The IceProd framework : Distributed data processing for the IceCube neutrino observatory
- 2015
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Ingår i: Journal of Parallel and Distributed Computing. - : Elsevier BV. - 0743-7315 .- 1096-0848. ; 75, s. 198-211
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Tidskriftsartikel (refereegranskat)abstract
- IceCube is a one-gigaton instrument located at the geographic South Pole, designed to detect cosmic neutrinos, identify the particle nature of dark matter, and study high-energy neutrinos themselves. Simulation of the IceCube detector and processing of data require a significant amount of computational resources. This paper presents the first detailed description of IceProd, a lightweight distributed management system designed to meet these requirements. It is driven by a central database in order to manage mass production of simulations and analysis of data produced by the IceCube detector. IceProd runs as a separate layer on top of other middleware and can take advantage of a variety of computing resources, including grids and batch systems such as CREAM, HTCondor, and PBS. This is accomplished by a set of dedicated daemons that process job submission in a coordinated fashion through the use of middleware plugins that serve to abstract the details of job submission and job management from the framework. (C) 2014 Elsevier Inc. All rights reserved.
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| 2. |
- Hong, Wei-Li, et al.
(författare)
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Boron concentrations and isotopic compositions in methane-derived authigenic carbonates : Constraints and limitations in reconstructing formation conditions
- 2022
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Ingår i: Earth and Planetary Science Letters. - : Elsevier BV. - 0012-821X .- 1385-013X. ; 579
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Tidskriftsartikel (refereegranskat)abstract
- The boron content and isotopic composition (δ11B), of marine carbonates have the potential to constrain CO2 chemistry during carbonate growth conditions. However, obtaining and interpreting boron compositions from authigenic carbonates in geological archives present several challenges that may substantially limit their application. In particular, contamination from non-carbonate phases during sample preparation must be carefully avoided, and a variety of controls on boron composition during authigenic growth conditions must be evaluated. To advance understanding of the use and limitations of boron in authigenic carbonates, we present data and modelling results on methane-derived authigenic carbonate (MDAC), a by-product of microbially mediated anaerobic oxidation of methane, taken from three cold seep sites along the Norwegian margin. We present a novel sequential leaching method to isolate the boron signals from the micritic (Mg-calcite) and cavity-filling (aragonitic) MDAC cements in these complex multi-phase samples. This method successfully minimizes contamination from non-carbonate phases. To investigate the factors that could potentially contribute to the observed boron signals, we construct a numerical model to simulate the evolution of MDAC δ11B and B/Ca ratios over its growth history. We show that diagenetic fluid composition, depths of precipitation, the physical properties of sediments (such as porosity), and mineral surface kinetics all contribute to the observed boron compositions in the different carbonate cements. While broad constraints may be placed on fluid composition, the multiple competing controls on boron in these diagenetic settings limit the ability to place unique solutions on fluid CO2 chemistry using boron in these authigenic carbonates.
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| 3. |
- Hong, Wei-Li, et al.
(författare)
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Interactions between deep formation fluid and gas hydrate dynamics inferred from pore fluid geochemistry at active pockmarks of the Vestnesa Ridge, west Svalbard margin
- 2021
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Ingår i: Marine and Petroleum Geology. - : Elsevier BV. - 0264-8172 .- 1873-4073. ; 127
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Tidskriftsartikel (refereegranskat)abstract
- Seafloor seepage sites along the Vestnesa Ridge off west-Svalbard have been, for decades, a natural laboratory for the studies of fluid flow and gas hydrate dynamics along passive continental margins. The lack of ground truth evidence for fluid composition and gas hydrate abundance deep in the sediment sequence however prohibits us from further assessing the current model of pockmark evolution from the region. A MARUM-MeBo 70 drilling cruise in 2016 aims to advance our understanding of the system by recovering sediments tens of meters below seafloor from two active pockmarks along Vestnesa Ridge. We report pore fluid composition data focusing on dissolved chloride, stable isotopes of water (delta O-18 and delta D), and the isotopic composition of dissolved boron (delta B-11). From one of the seepage sites, we detect a saline formation water with two layers where gas hydrates were recovered. This saline formation pore fluid is characterized by elevated chloride concentrations (up to 616 mM), high B/Cl ratios (9 x 10(-4) mol/mol), high delta O-18 and delta D isotopic signatures (+0.6 parts per thousand and +3.8 parts per thousand, respectively) and low 811B signatures (+35.0 parts per thousand), which collectively hint to a high temperature modification at great depths. Based on the dissolved chloride concentration profiles, we estimated up to 47% of pore space occupied by gas hydrate in the sediments shallower than 11.5 mbsf. The observation of bubble fabric in the recovered gas hydrates suggests formation during past periods of intensive gaseous methane seepage. The presence of these gas hydrates without associated positive anomalies in dissolved chloride concentrations however suggests that the decomposition of gas hydrate is as fast as its formation. Such a state of gas hydrates can be attributed to a relatively low methane supply transported by the saline formation water at present. Our findings based on pore fluid composition corroborate previous inferences along Vestnesa Ridge that fluids sustaining seepage have migrated from great depths and that the variable gaseous and aqueous phases through the gas hydrate stability zone control the distributions of authigenic carbonates and gas hydrates.
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