598 research outputs found

    The helium and carbon isotope characteristics of the Andean Convergent Margin

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Barry, P. H., De Moor, J. M., Chiodi, A., Aguilera, F., Hudak, M. R., Bekaert, D. V., Turner, S. J., Curtice, J., Seltzer, A. M., Jessen, G. L., Osses, E., Blamey, J. M., Amenabar, M. J., Selci, M., Cascone, M., Bastianoni, A., Nakagawa, M., Filipovich, R., Bustos, E., Schrenk, M. O. , Buongiorno, J., RamĂ­rez, C. J., Rogers, T. J., Lloyd, K. G. & Giovannelli, D. The helium and carbon isotope characteristics of the Andean Convergent Margin. Frontiers in Earth Science, 10, (2022): 897267, https://doi.org/10.3389/feart.2022.897267.Subduction zones represent the interface between Earth’s interior (crust and mantle) and exterior (atmosphere and oceans), where carbon and other volatile elements are actively cycled between Earth reservoirs by plate tectonics. Helium is a sensitive tracer of volatile sources and can be used to deconvolute mantle and crustal sources in arcs; however it is not thought to be recycled into the mantle by subduction processes. In contrast, carbon is readily recycled, mostly in the form of carbon-rich sediments, and can thus be used to understand volatile delivery via subduction. Further, carbon is chemically-reactive and isotope fractionation can be used to determine the main processes controlling volatile movements within arc systems. Here, we report helium isotope and abundance data for 42 deeply-sourced fluid and gas samples from the Central Volcanic Zone (CVZ) and Southern Volcanic Zone (SVZ) of the Andean Convergent Margin (ACM). Data are used to assess the influence of subduction parameters (e.g., crustal thickness, subduction inputs, and convergence rate) on the composition of volatiles in surface volcanic fluid and gas emissions. He isotopes from the CVZ backarc range from 0.1 to 2.6 RA (n = 23), with the highest values in the Puna and the lowest in the Sub-Andean foreland fold-and-thrust belt. Atmosphere-corrected He isotopes from the SVZ range from 0.7 to 5.0 RA (n = 19). Taken together, these data reveal a clear southeastward increase in 3He/4He, with the highest values (in the SVZ) falling below the nominal range associated with pure upper mantle helium (8 ± 1 RA), approaching the mean He isotope value for arc gases of (5.4 ± 1.9 RA). Notably, the lowest values are found in the CVZ, suggesting more significant crustal inputs (i.e., assimilation of 4He) to the helium budget. The crustal thickness in the CVZ (up to 70 km) is significantly larger than in the SVZ, where it is just ∌40 km. We suggest that crustal thickness exerts a primary control on the extent of fluid-crust interaction, as helium and other volatiles rise through the upper plate in the ACM. We also report carbon isotopes from (n = 11) sites in the CVZ, where ÎŽ13C varies between −15.3‰ and −1.2‰ [vs. Vienna Pee Dee Belemnite (VPDB)] and CO2/3He values that vary by over two orders of magnitude (6.9 × 108–1.7 × 1011). In the SVZ, carbon isotope ratios are also reported from (n = 13) sites and vary between −17.2‰ and −4.1‰. CO2/3He values vary by over four orders of magnitude (4.7 × 107–1.7 × 1012). Low ÎŽ13C and CO2/3He values are consistent with CO2 removal (e.g., calcite precipitation and gas dissolution) in shallow hydrothermal systems. Carbon isotope fractionation modeling suggests that calcite precipitation occurs at temperatures coincident with the upper temperature limit for life (122°C), suggesting that biology may play a role in C-He systematics of arc-related volcanic fluid and gas emissions.This work was principally supported by the NSF-FRES award 2121637 to PB, KL, and JM. Field work was also supported by award G-2016-7206 from the Alfred P. Sloan Foundation and the Deep Carbon Observatory to PB, KL, DG, and JM. Additional support came from The National Fund for Scientific and Technological Development of Chile (FONDECYT) Grant 11191138 (The National Research and Development Agency of Chile, ANID Chile), and COPAS COASTAL ANID FB210021 to GJ. DG was partially supported by funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program Grant Agreement No. 948972—COEVOLVE—ERC-2020-STG

    An Evaluation Schema for the Ethical Use of Autonomous Robotic Systems in Security Applications

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    The ARTEMIS under-ice AUV docking system

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    © 2017 Wiley Periodicals, Inc. The ARTEMIS docking system demonstrates autonomous docking capability applicable to robotic exploration of sub-ice oceans and sub-glacial lakes on planetary bodies, as well as here on Earth. In these applications, melted or drilled vertical access shafts restrict vehicle geometry as well as the in-water infrastructure that may be deployed. The ability of the vehicle to return reliably and precisely to the access point is critical for data return, battery charging, and/or vehicle recovery. This paper presents the mechanical, sensor, and software components that make up the ARTEMIS docking system, as well as results from field deployment of the system to McMurdo Sound, Antarctica in the austral spring of 2015. The mechanical design of the system allows the vehicle to approach the dock from any direction and to pitch up after docking for recovery through a vertical access shaft. It uses only a small volume of in-water equipment and may be deployed through a narrow vertical access shaft. The software of the system reduces position estimation error with a hierarchical combination of dead reckoning, acoustic aiding, and machine vision. The system provides critical operational robustness, enabling the vehicle to return autonomously and precisely to the access shaft and latch to the dock with no operator input

    Experimental Validation of Cryobot Thermal Models for the Exploration of Ocean Worlds

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    The tables in this repository represent the data used in the figures and analyses of the paper "Experimental Validation of Cryobot Thermal Models for the Exploration of Ocean Worlds", published in the Planetary Science Journal. The provided data was collected between 2020 and 2022.Work at the Jet Propulsion Laboratory, California Institute of Technology, was carried out under a contract (80NM0018D0004) with the National Aeronautics and Space Administration (NASA) and with funding from a NASA Scientific Exploration Subsurface Access Mechanism for Europa (SESAME) grant (80NM0018F0560). Work at the University of Washington was carried out under the same SESAME grant (80NM0018F0560). Work at Stone Aerospace and MIT was carried out under a separate NASA SESAME grant (80NSSC19K0612), as well as under the MIT TVML Fellowship

    PALVELUTUOTTEEN HINNOITTELUN KEHITTÄMINEN

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    TĂ€mĂ€n opinnĂ€ytetyön aiheena on palvelutuotteen hinnoittelun kehittĂ€minen. Tutkimuksen kohteena on Tili- ja isĂ€nnöitsijĂ€toimisto Ky. Tili- ja isĂ€nnöitsijĂ€toimisto Ky on Vaasassa toimiva tili- ja isĂ€nnöintitoimisto, joka tarjoaa taloushallinto- ja isĂ€nnöintipalveluita yrityksille. Tutkimuksen tavoitteena on kehittÀÀ Tili- ja isĂ€nnöitsijĂ€toimisto Ky:n isĂ€nnöitsijĂ€n palvelutuotteiden hinnoittelua. HinnoittelumenetelmĂ€ksi valittiin toimintoperusteinen hinnoittelu, jonka lĂ€htökohtana on selvittÀÀ asiakaskohtaisia vĂ€lillisiĂ€ kustannuksia. Kysymys oli suorite-kohtaisten kustannusten laskemisesta, eli toimintoperusteisesta prosessilaskennasta. Toimintoperusteinen prosessilaskenta tukee hinnoittelun pÀÀtöstĂ€. Toiminto-analyysin jĂ€lkeen selvitettiin resurssien kohdistumista yrityksen eri toiminnoille. Aluksi selvitettiin yrityksen kustannusajuri, jonka perusteella kustannukset on kohdistettu eri toiminnoille. Seuraavaksi selvitettiin toimintoajurin avulla toimintoihin liittyvĂ€t yksikkökustannukset. Tuotteiden hinnoittelussa myyntihinnan on tarkoituksena sisĂ€ltÀÀ kaikkien kustannusten lisĂ€ksi voittotavoite. Tutkimuksen teoriaosuuden keskeisiĂ€ asioita ovat toimintoperusteisen kustannuslaskennan, sekĂ€ hinnoittelun perusteiden esittely. Niiden avulla voidaan perustella hinnoittelupÀÀtöstĂ€ tukeva toimintolaskenta. OpinnĂ€ytetyössĂ€ esitellÀÀn lisĂ€ksi kustannusperusteista hinnoittelua sekĂ€ isĂ€nnöintiĂ€ ja tilitoimistoa yleisesti. TutkimusmenetelmĂ€nĂ€ kĂ€ytettiin kvalitatiivista eli laadullista tutkimusta. Tutkimuksen teoriaosuuteen kĂ€ytettiin toimintolaskennan, taloushallinnon alan sekĂ€ hinnoittelun teoriaan liittyvÀÀ kirjallisuutta. Aineistonkeruussa havainnoitiin yrityksen tilinpÀÀtöstĂ€ vuodelta 2016 ja yrityksen toimintaa liittyviĂ€ ohjelmia sekĂ€ tietokantoja. LisĂ€ksi haastateltiin Tili- ja isĂ€nnöitsijĂ€toimisto Ky:n omistajaa ja työntekijöitĂ€.This research was designed to develop the used pricing method for the case firm Tili- ja isĂ€nnöitsijĂ€toimisto Ky. The main area of this research focused on the main service products in property management. The case firm offers financial accounting and management services to house companies and other customer companies. Activity based costing was selected as the new pricing method in order to identify the customer-specific indirect costs. The aim of activity-based costing was to support pricing decisions for the case firm. In the implementation steps, activities must be identified first, and then the process continues with an activity analysis. Once the costs of activity and its drivers have been identified and its costs have been determined, then the costs of activity is allocated to the service product. In the allocation process, when the activity driver has been determined, the cost per unit can then be determined. Once the product cost per unit has been determined then the case firm considers the generated value of its service product, so the pricing of all the service product sales cover the fixed expenses with any remaining contribution margin providing profits. The theoretical study of this thesis introduced activity based costing and pricing to support activity based cost implementation and pricing decisions. In addition, it introduced cost based pricing and property management business and accounting firms in general. This research was implemented using the qualitative research method. The research material consists of related activity based costing, financial management, management accounting and pricing literature. The theoretical information was gathered from scientific research, academic books and some material was collect-ed from the Internet. The empirical data in this research was gathered by observing the case company’s financial statement from the year 2016 together with some business activities related programs and databases. In addition, was collected by interviewing the case company owner and the other employers of the company
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