- home
- Search
- NEANIAS Atmospheric Research Community
- Open Access
- Natural Sciences and Engineering Re...
- NEANIAS Atmospheric Research Community
- Open Access
- Natural Sciences and Engineering Re...
Loading
description Publicationkeyboard_double_arrow_right Other literature type 2013 Canada EnglishPublisher:Scholarship@Western Funded by:NSERCNSERCAuthors: Shankar, Bhairavi;Shankar, Bhairavi;Hypervelocity collisions of asteroids onto planetary bodies have catastrophic effects on the target rocks through the process of shock metamorphism. The resulting features, impact craters, are circular depressions with a sharp rim surrounded by an ejecta blanket of variably shocked rocks. With increasing impact energy, the inner crater cavity can preserve complex morphologies including terraced walls, central uplifts, and melted rocks. The lack of erosion due to the absence of water or an atmosphere makes the Moon the perfect target to study impact crater processes, in particular the distribution of highly shocked materials within impact craters of different sizes. This study focuses on the characterization and distribution of highly shocked impact melt deposits using multispectral satellite datasets around three complex craters on the farside of the Moon. The study sites have varying morphologies of central uplifts on the crater floor: 1) the 81 km Olcott crater has a cluster of peak hills; 2) Kovalevskaya crater is a 113 km diameter complex crater with a central peak; and 3) Schrodinger basin has a central peak ring. Models propose that the collapse of crater walls and central uplifts during the final stages of crater formation determine where much of the melt rich rocks are eventually emplaced. The results of this study indicate that for increasing crater sizes, the volume of melt-rich rocks generated also increases – at rates greater than model estimates. Impact melt deposits are emplaced beyond the crater rims at each of the sites and preserve a range of morphologies, including melt veneers, melt sheet, and ponded deposits. The regional and local topography, together with crater modification processes greatly affect where the impact melts are finally emplaced. The compositional analyses of the farside crust, using multispectral reflectance spectroscopy in the UV-VIS-NIR range, indicates that there is increasing evidence of highly mafic compositions (i.e., rocks rich in high-Ca pyroxene, olivine, spinel) intercalated within the original crustal highlands (rocks rich in plagioclase feldspar, and low-Ca pyroxenes) on the lunar farside, proving that the lunar farside is a far more geologically complicated terrain than originally assumed.
All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od______1548::d81522a30f969d3610e668bbd4192b3e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eu0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od______1548::d81522a30f969d3610e668bbd4192b3e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2019Publisher:Springer Science and Business Media LLC Funded by:NSERCNSERCMichelutti, Neal; Sowell, Preston; Tapia, Pedro M.; Grooms, Christopher; Polo, Martin; Gambetta, Alexandra; Ausejo, Carlos; Smol, John P.;AbstractPre-Hispanic artifacts and sacred architecture were recently discovered submerged in a large lake (Laguna Sibinacocha) in the Peruvian Andes. The underwater ruins indicate a dramatic shift in the region’s hydrology but the timing and triggers of this shift remain unknown. In a novel approach blending archaeology and paleoecology, we analyzed a sediment sequence from within one of the recovered artifacts, specifically a pot from the Late Intermediate Period (~1000–1400 CE). Radioisotopic dating of discrete sediment intervals sampled from the pot show a stratigraphically intact profile that preserves a history of change at this site. The pot’s basal sediment age places the timing of lake-level rise during the late ~1600s CE, which post-dates the end of the Inca Empire (1400–1532 CE) by approximately 150 years. The ubiquity of planktonic algae throughout the sediment profile suggests water levels remained high above the pot since its submergence. Paleoclimate data from the nearby Quelccaya ice core records indicate lake flooding followed a pronounced wet period beginning ~1520 CE. These data show the permanence of mean state changes in climate on the region’s hydrology, with clear implications for the study site (an important water resource for ~500,000 people) and other lakes in the rapidly warming Andes.
Europe PubMed Centra... arrow_drop_down Europe PubMed CentralArticle . 2020Full-Text: http://europepmc.org/articles/PMC7297799Data sources: PubMed CentralScientific ReportsArticle . 2019Full-Text: http://europepmc.org/articles/PMC6915777Data sources: PubMed Centraladd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1038/s41598-019-55422-1&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen gold 5 citations 5 popularity Top 10% influence Average impulse Average Powered by BIP!more_vert Europe PubMed Centra... arrow_drop_down Europe PubMed CentralArticle . 2020Full-Text: http://europepmc.org/articles/PMC7297799Data sources: PubMed CentralScientific ReportsArticle . 2019Full-Text: http://europepmc.org/articles/PMC6915777Data sources: PubMed Centraladd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1038/s41598-019-55422-1&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2022Publisher:MDPI AG Funded by:NSERC, NSF | Acquisition of a new nobl...NSERC ,NSF| Acquisition of a new noble gas mass spectrometer and extraction system for the University of MichiganDaniele Luigi Pinti; Marie Haut-Labourdette; André Poirier; Marion Saby; Vincent J. van Hinsberg; Kim Berlo; Maria Clara Castro; Bjarni Gautason; Ásgerður K. Sigurðardóttir;The determination of the current and past recharge sources, as well as the reconstruction of the timing of the recharge in geothermal reservoirs, is required in order to correctly assess the resource potential of these systems. Theistareykir is a newly developed geothermal field close to the well-known exploited fields of Krafla and Námafjall in NE Iceland. In this study, the 87Sr/86Sr ratios measured in deep geothermal fluids are presented and, together with the Cl and noble gas signatures, are used to place constraints on the fluid sources. The Cl/Sr and 87Sr/86Sr ratios show a peculiar and unique composition among Icelandic geothermal fluids. The 87Sr/86Sr ratios range from 0.70355 to 0.70671, suggesting the presence of a significant seawater component—possibly marine aerosols added to rain or snowfall—as well as an additional source of Sr leached from local basalts. Moreover, a correlation between the atmospheric noble gas (ANGs) elemental ratios Ne/Ar, Kr/Ar and Xe/Ar, and the 87Sr/86Sr ratios is observed. The latter results from the mixing of meteoric water with Sr leached from local basalts, meteoric water containing unrelated Sr from seawater, and recharge water with ANGs derived from trapped air bubbles in snow. We suggest that the combined ANGs and Sr seawater signatures are representative of a glacial water source derived from the melting of compacting snow.
Geosciences arrow_drop_down GeosciencesOther literature type . Article . 2022 . Peer-reviewedLicense: CC BYFull-Text: http://www.mdpi.com/2076-3263/12/3/119/pdfadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.3390/geosciences12030119&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 1 citations 1 popularity Average influence Average impulse Average Powered by BIP!more_vert Geosciences arrow_drop_down GeosciencesOther literature type . Article . 2022 . Peer-reviewedLicense: CC BYFull-Text: http://www.mdpi.com/2076-3263/12/3/119/pdfadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.3390/geosciences12030119&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2018 CanadaPublisher:Wiley Funded by:NSERCNSERCAuthors: Sarah Peirce; Peter Ashmore; Pauline Leduc;Sarah Peirce; Peter Ashmore; Pauline Leduc;doi: 10.1002/esp.4400
AbstractThe morphological active width, defined as the lateral extent of bed material displacement over time, is a fundamental parameter in multi‐threaded gravel‐bed rivers, linking complex channel dynamics to bedload transport. Here, results are presented from five constant discharge experiments, and three event hydrographs, covering a range of flow strengths and channel configurations for which morphological change, bedload transport rates, and stream power were measured in a physical model. Changes in channel morphology were determined via differencing of photogrammetrically‐derived digital elevation models (DEMs) of the model surface generated at regular intervals over the course of ~115 h of experimental runs. Independent measures of total bedload output were made using downstream sediment baskets. Results indicate that the morphological active width increases with total and dimensionless stream power and is strongly and positively correlated with bulk change (total volume of bed material displaced over time) and active braiding intensity (ABI). Although there is considerable scatter due to the inherent variability in braided river morphodynamics, the active width is positively correlated with independent measurements of bedload transport rate. Active width, bulk change, and bedload transport rates were all negligible below a dimensionless stream power threshold value of ~ 0.09, above which all increase with flow strength. Therefore, the active width could be used as a general predictor of bulk change and bedload transport rates, which in turn could be approximated from total and dimensionless stream power or ABI in gravel‐bed braided rivers. Furthermore, results highlight the importance of the active width, rather than the morphological active depth, in predicting volumes of change and bedload transport rates. The results contribute to the larger goals of better understanding braided river morphodynamics, creating large high‐resolution datasets of channel change for model calibration and validation, and developing morphological methods for predicting bedload transport rates in braiding river systems. Copyright © 2018 John Wiley & Sons, Ltd.
Earth Surface Proces... arrow_drop_down Earth Surface Processes and LandformsArticle . 2018 . Peer-reviewedLicense: Wiley Online Library User AgreementData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1002/esp.4400&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesbronze 18 citations 18 popularity Top 10% influence Average impulse Top 10% Powered by BIP!more_vert Earth Surface Proces... arrow_drop_down Earth Surface Processes and LandformsArticle . 2018 . Peer-reviewedLicense: Wiley Online Library User AgreementData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1002/esp.4400&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2018Publisher:Springer Science and Business Media LLC Funded by:NSERCNSERCTheetso Motsamai; Jeff W. Harris; Thomas Stachel; D. Graham Pearson; John Armstrong;Mineral inclusions in diamonds play a critical role in constraining the relationship between diamonds and mantle lithologies. Here we report the first major and trace element study of mineral inclusions in diamonds from the Karowe Mine in north-east Botswana, along the western edge of the Zimbabwe Craton. From a total of 107 diamonds, 134 silicate, 15 oxide, and 22 sulphide inclusions were recovered. The results reveal that 53% of Karowe inclusion-bearing diamonds derived from eclogitic sources, 44% are peridotitic, 2% have a sublithospheric origin, and 1% are websteritic. The dominant eclogitic diamond substrates sampled at Karowe are compositionally heterogeneous, as reflected in wide ranges in the CaO contents (4–16 wt%) of garnets and the Mg# (69–92) and jadeite contents (14–48 mol%) of clinopyroxenes. Calculated bulk rock REEN patterns indicate that both shallow and deep levels of the subducted slab(s) were sampled, including cumulate-like protoliths. Peridotitic garnet compositions largely derive from harzburgite/dunite substrates (~90%), with almost half the garnets having CaO contents <1.8 wt%, consistent with pyroxene-free (dunitic) sources. The highly depleted character of the peridotitic diamond substrates is further documented by the high mean and median Mg# (93.1) of olivine inclusions. One low-Ca garnet records a very high Cr2O3 content (14.7 wt%), implying that highly depleted cratonic lithosphere at the time of diamond formation extended to at least 220 km depth. Inclusion geothermobarometry indicates that the formation of peridotitic diamonds occurred along a 39–40 mW/m2 model geotherm. A sublithospheric inclusion suite is established by three eclogitic garnets containing a majorite component, a feature so far unique within the Orapa cluster. These low- and high-Ca majoritic garnets follow pyroxenitic and eclogitic trends of majoritic substitution, respectively. The origin of the majorite-bearing diamonds is estimated to be between 330 to 420 km depth, straddling the asthenosphere–transition zone boundary. This new observation of superdeep mineral inclusions in Karowe diamonds is consistent with a sublithospheric origin for the exceptionally large diamonds from this mine.
CORE (RIOXX-UK Aggre... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1007/s00710-018-0604-9&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesbronze 11 citations 11 popularity Top 10% influence Average impulse Top 10% Powered by BIP!download 91download downloads 91 Powered bymore_vert CORE (RIOXX-UK Aggre... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1007/s00710-018-0604-9&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Other literature type 2018 United Kingdom, United Kingdom, NetherlandsPublisher:Elsevier BV Funded by:UKRI | A new method for mapping ..., NSERCUKRI| A new method for mapping stresses in mantle rocks: Dislocation density from electron-backscatter diffraction ,NSERCAmbrose, Tyler; Wallis, David; Hansen, Lars; Waters, Dave; Searle, Michael; Structural geology and EM; Structural geology & tectonics;handle: 1874/363315
Studies of experimentally deformed rocks and small-scale natural shear zones have demonstrated that volumetrically minor phases can control strain localisation by limiting grain growth and promoting grain-size sensitive deformation mechanisms. These small-scale studies are often used to infer a critical role for minor phases in the development of plate boundaries. However, the role of minor phases in strain localisation at an actual plate boundary remains to be tested by direct observation. In order to test the hypothesis that minor phases control strain localisation at plate boundaries, we conducted microstructural analyses of peridotite samples collected along a ∼1 km transect across the base of the Oman-United Arab Emirates (UAE) ophiolite. The base of the ophiolite is marked by the Semail thrust, which represents the now exhumed contact between subducted oceanic crust and the overlying mantle wedge. As such, the base of the ophiolite provides the opportunity to directly examine a former plate boundary. Our results demonstrate that the mean olivine grain size is inversely proportional to the abundance of minor phases (primarily orthopyroxene, as well as clinopyroxene, hornblende, and spinel), consistent with suppression of grain growth by grain-boundary pinning. Our results also reveal that mean olivine grain size is proportional to CPO strength (both of which generally decrease towards the metamorphic sole), suggesting that the fraction of strain produced by different deformation mechanisms varied spatially. Experimentally-derived flow laws indicate that under the inferred deformation conditions, the viscosity of olivine was grain-size sensitive. As such, grain size, and thereby the abundance of minor phases, influenced viscosity during subduction-related deformation along the base of the mantle wedge. We calculate an order of magnitude decrease in the viscosity of olivine towards the base of the ophiolite, which suggests strain was localised near the subduction interface. Our data indicate that this rheological weakening was primarily the result of more abundant minor phases near the base of the ophiolite. Our interpretations are consistent with those of previous studies on experimentally deformed rocks and smaller-scale natural shear zones that indicate minor phases can exert the primary control on strain localisation. However, our study demonstrates for the first time that minor phases can control strain localisation at the scales relevant to a major plate boundary.
Apollo arrow_drop_down Oxford University Research ArchiveOther literature type . 2018Data sources: Oxford University Research ArchiveNARCIS; Utrecht University RepositoryArticle . 2018Earth and Planetary Science LettersArticle . 2018 . Peer-reviewedLicense: Elsevier TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1016/j.epsl.2018.03.027&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routeshybrid 25 citations 25 popularity Top 10% influence Average impulse Top 10% Powered by BIP!visibility 1visibility views 1 download downloads 86 Powered bymore_vert Apollo arrow_drop_down Oxford University Research ArchiveOther literature type . 2018Data sources: Oxford University Research ArchiveNARCIS; Utrecht University RepositoryArticle . 2018Earth and Planetary Science LettersArticle . 2018 . Peer-reviewedLicense: Elsevier TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1016/j.epsl.2018.03.027&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2022Publisher:Canadian Science Publishing Funded by:NSERCNSERCAuthors: Michel Paquette; Daniel Fortier; Scott F. Lamoureux;Michel Paquette; Daniel Fortier; Scott F. Lamoureux;Ground ice distribution and abundance have wide-ranging effects on periglacial environments and possible impacts on climate change scenarios. In contrast, very few studies measure ground ice in the High Arctic, especially in polar deserts and where coarse surficial material complicates coring operations. Ground ice volumes and cryostructures were determined for eight sites in a polar desert, near Resolute Bay, Nunavut, chosen for their hydrogeomorphic classification. Dry, unvegetated polar desert sites exhibited ice content close to soil porosity, with a <45 cm thick ice-enriched transition zone. In wetland sites, suspended cryostructures and ice dominated cryofacies (ice content at least 2× soil porosity values) were prevalent in the upper ∼2 m of permafrost. Average ground ice saturation at those locations exceeded porosity values by a factor between 1.8 and 20.1 and by up to two orders of magnitude at the ∼10 cm vertical scale. Sites with the highest ice contents were historically submerged wetlands with a history of sediment supply, sustained water availability, and syngenetic and quasi-syngenetic permafrost aggradation. Ice enrichment in those environments were mainly caused by the strong upward freezing potential beneath the thaw front, which, combined with abundant water supply, caused ice aggradation and frost heaving to form lithalsa plateaus. Most of the sites already expressed cryostratigraphic evidence of permafrost degradation. Permafrost degradation carries important ecological ramifications, as wetland locations are the most productive, life-supporting oases in the otherwise relatively barren landscape, carrying essential functions linked with hydrological processes and nutrient and contaminant cycling.
Canadian Journal of ... arrow_drop_down Canadian Journal of Earth SciencesArticle . 2022 . Peer-reviewedLicense: CSP TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1139/cjes-2020-0134&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesbronze 4 citations 4 popularity Top 10% influence Average impulse Average Powered by BIP!more_vert Canadian Journal of ... arrow_drop_down Canadian Journal of Earth SciencesArticle . 2022 . Peer-reviewedLicense: CSP TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1139/cjes-2020-0134&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Preprint 2023Publisher:Elsevier BV Funded by:NSERCNSERCAuthors: Eric M. Roy; Jun Zhou; Frank Wania; Daniel Obrist;Eric M. Roy; Jun Zhou; Frank Wania; Daniel Obrist;Direct measurements of gaseous elemental mercury (GEM) exchanges over global ecosystems are challenging and require extensive and costly measurement systems. Here, we explore the use of atmospheric GEM concentration variability and passive samplers to assess underlying ecosystem GEM exchanges at two rural temperate forests in the northeastern United States. We find strong temporal alignments between atmospheric GEM concentration declines and ecosystem GEM deposition in spring at both forests, which followed patterns of CO
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.2139/ssrn.4481271&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routeshybrid 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.2139/ssrn.4481271&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Preprint , Other literature type 2020Publisher:Copernicus GmbH Funded by:NSF | Collaborative Research: G..., EC | BYONIC, NSF | GEOTRACES Arctic Section:... +5 projectsNSF| Collaborative Research: GEOTRACES Arctic Section: Marine Cycling of Bioactive Trace Metals in the Arctic Ocean ,EC| BYONIC ,NSF| GEOTRACES Arctic Section: Shipboard determination of key trace elements ,NSF| US GEOTRACES PMT: Cobalt Biogeochemical Cycling and Connections to Metalloenzymes in the Pacific Ocean ,NSF| Collaborative Research: Biogeochemical Cycling of Particulate Trace Elements in the Western Arctic Basin ,NSF| Collaborative Research: Underexplored connections between nitrogen and trace metal cycling in oxygen minimum zones mediated by metalloenzyme inventories ,NSERC ,NSF| GEOTRACES Arctic Section: Collaborative Research: Biogeochemical cycling of particulate trace elements in the western Arctic basinRandelle M. Bundy; Alessandro Tagliabue; Nicholas J. Hawco; Peter L. Morton; Benjamin S. Twining; Mariko Hatta; Abigail E. Noble; Mattias R. Cape; Seth G. John; Jay T. Cullen; Mak A. Saito;Cobalt (Co) is an important bioactive trace metal that is the metal cofactor in cobalamin (vitamin B12) which can limit or co-limit phytoplankton growth in many regions of the ocean. Total dissolved and labile Co measurements in the Canadian sector of the Arctic Ocean during the U.S. GEOTRACES Arctic expedition (GN01) and the Canadian International Polar Year GEOTRACES expedition (GIPY14) revealed a dynamic biogeochemical cycle for Co in this basin. The major sources of Co in the Arctic were from shelf regions and rivers, with only minimal contributions from other freshwater sources (sea ice, snow) and eolian deposition. The most striking feature was the extremely high concentrations of dissolved Co in the upper 100 m, with concentrations routinely exceeding 800 pmol L−1 over the shelf regions. This plume of high Co persisted throughout the Arctic basin and extended to the North Pole, where sources of Co shifted from primarily shelf-derived to riverine, as freshwater from Arctic rivers was entrained in the Transpolar Drift. Dissolved Co was also strongly organically complexed in the Arctic, ranging from 70 % to 100 % complexed in the surface and deep ocean, respectively. Deep-water concentrations of dissolved Co were remarkably consistent throughout the basin (∼55 pmol L−1), with concentrations reflecting those of deep Atlantic water and deep-ocean scavenging of dissolved Co. A biogeochemical model of Co cycling was used to support the hypothesis that the majority of the high surface Co in the Arctic was emanating from the shelf. The model showed that the high concentrations of Co observed were due to the large shelf area of the Arctic, as well as to dampened scavenging of Co by manganese-oxidizing (Mn-oxidizing) bacteria due to the lower temperatures. The majority of this scavenging appears to have occurred in the upper 200 m, with minimal additional scavenging below this depth. Evidence suggests that both dissolved Co (dCo) and labile Co (LCo) are increasing over time on the Arctic shelf, and these limited temporal results are consistent with other tracers in the Arctic. These elevated surface concentrations of Co likely lead to a net flux of Co out of the Arctic, with implications for downstream biological uptake of Co in the North Atlantic and elevated Co in North Atlantic Deep Water. Understanding the current distributions of Co in the Arctic will be important for constraining changes to Co inputs resulting from regional intensification of freshwater fluxes from ice and permafrost melt in response to ongoing climate change.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.5194/bg-2020-84&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 17 citations 17 popularity Top 10% influence Average impulse Top 10% Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.5194/bg-2020-84&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Preprint 2009Publisher:IOP Publishing Funded by:NSERCNSERCDaigle, Olivier; Carignan, Claude; Gach, Jean-Luc; Guillaume, Christian; Lessard, Simon; Fortin, Charles-Anthony; Blais-Ouellette, Sebastien;An EMCCD camera, designed from the ground up for extreme faint flux imaging, is presented. CCCP, the CCD Controller for Counting Photons, has been integrated with a CCD97 EMCCD from e2v technologies into a scientific camera at the Laboratoire d'Astrophysique Exp\'erimentale (LAE), Universit\'e de Montr\'eal. This new camera achieves sub-electron read-out noise and very low Clock Induced Charge (CIC) levels, which are mandatory for extreme faint flux imaging. Data gathered with the camera suggests that through enhanced manufacturing processes, which would avoid traps from being created, and with the help of the clock shapes producible with CCCP, the CIC generated during the vertical transfer could be virtually suppressed. The camera has been characterized in laboratory and used on the Observatoire du Mont M\'egantic 1.6-m telescope. The performance of the camera is discussed and experimental data with the first scientific data are presented. Comment: 11 pages, 5 figures, Proceedings of the Detectors for Astronomy 2009 conference
Publications of the ... arrow_drop_down https://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: DatacitePublications of the Astronomical Society of the PacificArticle . 2009 . Peer-reviewedData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1086/605449&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen bronze 37 citations 37 popularity Top 10% influence Top 10% impulse Top 10% Powered by BIP!more_vert Publications of the ... arrow_drop_down https://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: DatacitePublications of the Astronomical Society of the PacificArticle . 2009 . Peer-reviewedData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1086/605449&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eu
Loading
description Publicationkeyboard_double_arrow_right Other literature type 2013 Canada EnglishPublisher:Scholarship@Western Funded by:NSERCNSERCAuthors: Shankar, Bhairavi;Shankar, Bhairavi;Hypervelocity collisions of asteroids onto planetary bodies have catastrophic effects on the target rocks through the process of shock metamorphism. The resulting features, impact craters, are circular depressions with a sharp rim surrounded by an ejecta blanket of variably shocked rocks. With increasing impact energy, the inner crater cavity can preserve complex morphologies including terraced walls, central uplifts, and melted rocks. The lack of erosion due to the absence of water or an atmosphere makes the Moon the perfect target to study impact crater processes, in particular the distribution of highly shocked materials within impact craters of different sizes. This study focuses on the characterization and distribution of highly shocked impact melt deposits using multispectral satellite datasets around three complex craters on the farside of the Moon. The study sites have varying morphologies of central uplifts on the crater floor: 1) the 81 km Olcott crater has a cluster of peak hills; 2) Kovalevskaya crater is a 113 km diameter complex crater with a central peak; and 3) Schrodinger basin has a central peak ring. Models propose that the collapse of crater walls and central uplifts during the final stages of crater formation determine where much of the melt rich rocks are eventually emplaced. The results of this study indicate that for increasing crater sizes, the volume of melt-rich rocks generated also increases – at rates greater than model estimates. Impact melt deposits are emplaced beyond the crater rims at each of the sites and preserve a range of morphologies, including melt veneers, melt sheet, and ponded deposits. The regional and local topography, together with crater modification processes greatly affect where the impact melts are finally emplaced. The compositional analyses of the farside crust, using multispectral reflectance spectroscopy in the UV-VIS-NIR range, indicates that there is increasing evidence of highly mafic compositions (i.e., rocks rich in high-Ca pyroxene, olivine, spinel) intercalated within the original crustal highlands (rocks rich in plagioclase feldspar, and low-Ca pyroxenes) on the lunar farside, proving that the lunar farside is a far more geologically complicated terrain than originally assumed.
All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od______1548::d81522a30f969d3610e668bbd4192b3e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eu0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=od______1548::d81522a30f969d3610e668bbd4192b3e&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2019Publisher:Springer Science and Business Media LLC Funded by:NSERCNSERCMichelutti, Neal; Sowell, Preston; Tapia, Pedro M.; Grooms, Christopher; Polo, Martin; Gambetta, Alexandra; Ausejo, Carlos; Smol, John P.;AbstractPre-Hispanic artifacts and sacred architecture were recently discovered submerged in a large lake (Laguna Sibinacocha) in the Peruvian Andes. The underwater ruins indicate a dramatic shift in the region’s hydrology but the timing and triggers of this shift remain unknown. In a novel approach blending archaeology and paleoecology, we analyzed a sediment sequence from within one of the recovered artifacts, specifically a pot from the Late Intermediate Period (~1000–1400 CE). Radioisotopic dating of discrete sediment intervals sampled from the pot show a stratigraphically intact profile that preserves a history of change at this site. The pot’s basal sediment age places the timing of lake-level rise during the late ~1600s CE, which post-dates the end of the Inca Empire (1400–1532 CE) by approximately 150 years. The ubiquity of planktonic algae throughout the sediment profile suggests water levels remained high above the pot since its submergence. Paleoclimate data from the nearby Quelccaya ice core records indicate lake flooding followed a pronounced wet period beginning ~1520 CE. These data show the permanence of mean state changes in climate on the region’s hydrology, with clear implications for the study site (an important water resource for ~500,000 people) and other lakes in the rapidly warming Andes.
Europe PubMed Centra... arrow_drop_down Europe PubMed CentralArticle . 2020Full-Text: http://europepmc.org/articles/PMC7297799Data sources: PubMed CentralScientific ReportsArticle . 2019Full-Text: http://europepmc.org/articles/PMC6915777Data sources: PubMed Centraladd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1038/s41598-019-55422-1&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen gold 5 citations 5 popularity Top 10% influence Average impulse Average Powered by BIP!more_vert Europe PubMed Centra... arrow_drop_down Europe PubMed CentralArticle . 2020Full-Text: http://europepmc.org/articles/PMC7297799Data sources: PubMed CentralScientific ReportsArticle . 2019Full-Text: http://europepmc.org/articles/PMC6915777Data sources: PubMed Centraladd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1038/s41598-019-55422-1&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2022Publisher:MDPI AG Funded by:NSERC, NSF | Acquisition of a new nobl...NSERC ,NSF| Acquisition of a new noble gas mass spectrometer and extraction system for the University of MichiganDaniele Luigi Pinti; Marie Haut-Labourdette; André Poirier; Marion Saby; Vincent J. van Hinsberg; Kim Berlo; Maria Clara Castro; Bjarni Gautason; Ásgerður K. Sigurðardóttir;The determination of the current and past recharge sources, as well as the reconstruction of the timing of the recharge in geothermal reservoirs, is required in order to correctly assess the resource potential of these systems. Theistareykir is a newly developed geothermal field close to the well-known exploited fields of Krafla and Námafjall in NE Iceland. In this study, the 87Sr/86Sr ratios measured in deep geothermal fluids are presented and, together with the Cl and noble gas signatures, are used to place constraints on the fluid sources. The Cl/Sr and 87Sr/86Sr ratios show a peculiar and unique composition among Icelandic geothermal fluids. The 87Sr/86Sr ratios range from 0.70355 to 0.70671, suggesting the presence of a significant seawater component—possibly marine aerosols added to rain or snowfall—as well as an additional source of Sr leached from local basalts. Moreover, a correlation between the atmospheric noble gas (ANGs) elemental ratios Ne/Ar, Kr/Ar and Xe/Ar, and the 87Sr/86Sr ratios is observed. The latter results from the mixing of meteoric water with Sr leached from local basalts, meteoric water containing unrelated Sr from seawater, and recharge water with ANGs derived from trapped air bubbles in snow. We suggest that the combined ANGs and Sr seawater signatures are representative of a glacial water source derived from the melting of compacting snow.
Geosciences arrow_drop_down GeosciencesOther literature type . Article . 2022 . Peer-reviewedLicense: CC BYFull-Text: http://www.mdpi.com/2076-3263/12/3/119/pdfadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.3390/geosciences12030119&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 1 citations 1 popularity Average influence Average impulse Average Powered by BIP!more_vert Geosciences arrow_drop_down GeosciencesOther literature type . Article . 2022 . Peer-reviewedLicense: CC BYFull-Text: http://www.mdpi.com/2076-3263/12/3/119/pdfadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.3390/geosciences12030119&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2018 CanadaPublisher:Wiley Funded by:NSERCNSERCAuthors: Sarah Peirce; Peter Ashmore; Pauline Leduc;Sarah Peirce; Peter Ashmore; Pauline Leduc;doi: 10.1002/esp.4400
AbstractThe morphological active width, defined as the lateral extent of bed material displacement over time, is a fundamental parameter in multi‐threaded gravel‐bed rivers, linking complex channel dynamics to bedload transport. Here, results are presented from five constant discharge experiments, and three event hydrographs, covering a range of flow strengths and channel configurations for which morphological change, bedload transport rates, and stream power were measured in a physical model. Changes in channel morphology were determined via differencing of photogrammetrically‐derived digital elevation models (DEMs) of the model surface generated at regular intervals over the course of ~115 h of experimental runs. Independent measures of total bedload output were made using downstream sediment baskets. Results indicate that the morphological active width increases with total and dimensionless stream power and is strongly and positively correlated with bulk change (total volume of bed material displaced over time) and active braiding intensity (ABI). Although there is considerable scatter due to the inherent variability in braided river morphodynamics, the active width is positively correlated with independent measurements of bedload transport rate. Active width, bulk change, and bedload transport rates were all negligible below a dimensionless stream power threshold value of ~ 0.09, above which all increase with flow strength. Therefore, the active width could be used as a general predictor of bulk change and bedload transport rates, which in turn could be approximated from total and dimensionless stream power or ABI in gravel‐bed braided rivers. Furthermore, results highlight the importance of the active width, rather than the morphological active depth, in predicting volumes of change and bedload transport rates. The results contribute to the larger goals of better understanding braided river morphodynamics, creating large high‐resolution datasets of channel change for model calibration and validation, and developing morphological methods for predicting bedload transport rates in braiding river systems. Copyright © 2018 John Wiley & Sons, Ltd.
Earth Surface Proces... arrow_drop_down Earth Surface Processes and LandformsArticle . 2018 . Peer-reviewedLicense: Wiley Online Library User AgreementData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1002/esp.4400&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesbronze 18 citations 18 popularity Top 10% influence Average impulse Top 10% Powered by BIP!more_vert Earth Surface Proces... arrow_drop_down Earth Surface Processes and LandformsArticle . 2018 . Peer-reviewedLicense: Wiley Online Library User AgreementData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1002/esp.4400&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2018Publisher:Springer Science and Business Media LLC Funded by:NSERCNSERCTheetso Motsamai; Jeff W. Harris; Thomas Stachel; D. Graham Pearson; John Armstrong;Mineral inclusions in diamonds play a critical role in constraining the relationship between diamonds and mantle lithologies. Here we report the first major and trace element study of mineral inclusions in diamonds from the Karowe Mine in north-east Botswana, along the western edge of the Zimbabwe Craton. From a total of 107 diamonds, 134 silicate, 15 oxide, and 22 sulphide inclusions were recovered. The results reveal that 53% of Karowe inclusion-bearing diamonds derived from eclogitic sources, 44% are peridotitic, 2% have a sublithospheric origin, and 1% are websteritic. The dominant eclogitic diamond substrates sampled at Karowe are compositionally heterogeneous, as reflected in wide ranges in the CaO contents (4–16 wt%) of garnets and the Mg# (69–92) and jadeite contents (14–48 mol%) of clinopyroxenes. Calculated bulk rock REEN patterns indicate that both shallow and deep levels of the subducted slab(s) were sampled, including cumulate-like protoliths. Peridotitic garnet compositions largely derive from harzburgite/dunite substrates (~90%), with almost half the garnets having CaO contents <1.8 wt%, consistent with pyroxene-free (dunitic) sources. The highly depleted character of the peridotitic diamond substrates is further documented by the high mean and median Mg# (93.1) of olivine inclusions. One low-Ca garnet records a very high Cr2O3 content (14.7 wt%), implying that highly depleted cratonic lithosphere at the time of diamond formation extended to at least 220 km depth. Inclusion geothermobarometry indicates that the formation of peridotitic diamonds occurred along a 39–40 mW/m2 model geotherm. A sublithospheric inclusion suite is established by three eclogitic garnets containing a majorite component, a feature so far unique within the Orapa cluster. These low- and high-Ca majoritic garnets follow pyroxenitic and eclogitic trends of majoritic substitution, respectively. The origin of the majorite-bearing diamonds is estimated to be between 330 to 420 km depth, straddling the asthenosphere–transition zone boundary. This new observation of superdeep mineral inclusions in Karowe diamonds is consistent with a sublithospheric origin for the exceptionally large diamonds from this mine.
CORE (RIOXX-UK Aggre... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1007/s00710-018-0604-9&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesbronze 11 citations 11 popularity Top 10% influence Average impulse Top 10% Powered by BIP!download 91download downloads 91 Powered bymore_vert CORE (RIOXX-UK Aggre... arrow_drop_down add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1007/s00710-018-0604-9&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Other literature type 2018 United Kingdom, United Kingdom, NetherlandsPublisher:Elsevier BV Funded by:UKRI | A new method for mapping ..., NSERCUKRI| A new method for mapping stresses in mantle rocks: Dislocation density from electron-backscatter diffraction ,NSERCAmbrose, Tyler; Wallis, David; Hansen, Lars; Waters, Dave; Searle, Michael; Structural geology and EM; Structural geology & tectonics;handle: 1874/363315
Studies of experimentally deformed rocks and small-scale natural shear zones have demonstrated that volumetrically minor phases can control strain localisation by limiting grain growth and promoting grain-size sensitive deformation mechanisms. These small-scale studies are often used to infer a critical role for minor phases in the development of plate boundaries. However, the role of minor phases in strain localisation at an actual plate boundary remains to be tested by direct observation. In order to test the hypothesis that minor phases control strain localisation at plate boundaries, we conducted microstructural analyses of peridotite samples collected along a ∼1 km transect across the base of the Oman-United Arab Emirates (UAE) ophiolite. The base of the ophiolite is marked by the Semail thrust, which represents the now exhumed contact between subducted oceanic crust and the overlying mantle wedge. As such, the base of the ophiolite provides the opportunity to directly examine a former plate boundary. Our results demonstrate that the mean olivine grain size is inversely proportional to the abundance of minor phases (primarily orthopyroxene, as well as clinopyroxene, hornblende, and spinel), consistent with suppression of grain growth by grain-boundary pinning. Our results also reveal that mean olivine grain size is proportional to CPO strength (both of which generally decrease towards the metamorphic sole), suggesting that the fraction of strain produced by different deformation mechanisms varied spatially. Experimentally-derived flow laws indicate that under the inferred deformation conditions, the viscosity of olivine was grain-size sensitive. As such, grain size, and thereby the abundance of minor phases, influenced viscosity during subduction-related deformation along the base of the mantle wedge. We calculate an order of magnitude decrease in the viscosity of olivine towards the base of the ophiolite, which suggests strain was localised near the subduction interface. Our data indicate that this rheological weakening was primarily the result of more abundant minor phases near the base of the ophiolite. Our interpretations are consistent with those of previous studies on experimentally deformed rocks and smaller-scale natural shear zones that indicate minor phases can exert the primary control on strain localisation. However, our study demonstrates for the first time that minor phases can control strain localisation at the scales relevant to a major plate boundary.
Apollo arrow_drop_down Oxford University Research ArchiveOther literature type . 2018Data sources: Oxford University Research ArchiveNARCIS; Utrecht University RepositoryArticle . 2018Earth and Planetary Science LettersArticle . 2018 . Peer-reviewedLicense: Elsevier TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1016/j.epsl.2018.03.027&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routeshybrid 25 citations 25 popularity Top 10% influence Average impulse Top 10% Powered by BIP!visibility 1visibility views 1 download downloads 86 Powered bymore_vert Apollo arrow_drop_down Oxford University Research ArchiveOther literature type . 2018Data sources: Oxford University Research ArchiveNARCIS; Utrecht University RepositoryArticle . 2018Earth and Planetary Science LettersArticle . 2018 . Peer-reviewedLicense: Elsevier TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1016/j.epsl.2018.03.027&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article 2022Publisher:Canadian Science Publishing Funded by:NSERCNSERCAuthors: Michel Paquette; Daniel Fortier; Scott F. Lamoureux;Michel Paquette; Daniel Fortier; Scott F. Lamoureux;Ground ice distribution and abundance have wide-ranging effects on periglacial environments and possible impacts on climate change scenarios. In contrast, very few studies measure ground ice in the High Arctic, especially in polar deserts and where coarse surficial material complicates coring operations. Ground ice volumes and cryostructures were determined for eight sites in a polar desert, near Resolute Bay, Nunavut, chosen for their hydrogeomorphic classification. Dry, unvegetated polar desert sites exhibited ice content close to soil porosity, with a <45 cm thick ice-enriched transition zone. In wetland sites, suspended cryostructures and ice dominated cryofacies (ice content at least 2× soil porosity values) were prevalent in the upper ∼2 m of permafrost. Average ground ice saturation at those locations exceeded porosity values by a factor between 1.8 and 20.1 and by up to two orders of magnitude at the ∼10 cm vertical scale. Sites with the highest ice contents were historically submerged wetlands with a history of sediment supply, sustained water availability, and syngenetic and quasi-syngenetic permafrost aggradation. Ice enrichment in those environments were mainly caused by the strong upward freezing potential beneath the thaw front, which, combined with abundant water supply, caused ice aggradation and frost heaving to form lithalsa plateaus. Most of the sites already expressed cryostratigraphic evidence of permafrost degradation. Permafrost degradation carries important ecological ramifications, as wetland locations are the most productive, life-supporting oases in the otherwise relatively barren landscape, carrying essential functions linked with hydrological processes and nutrient and contaminant cycling.
Canadian Journal of ... arrow_drop_down Canadian Journal of Earth SciencesArticle . 2022 . Peer-reviewedLicense: CSP TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1139/cjes-2020-0134&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesbronze 4 citations 4 popularity Top 10% influence Average impulse Average Powered by BIP!more_vert Canadian Journal of ... arrow_drop_down Canadian Journal of Earth SciencesArticle . 2022 . Peer-reviewedLicense: CSP TDMData sources: Crossrefadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1139/cjes-2020-0134&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Preprint 2023Publisher:Elsevier BV Funded by:NSERCNSERCAuthors: Eric M. Roy; Jun Zhou; Frank Wania; Daniel Obrist;Eric M. Roy; Jun Zhou; Frank Wania; Daniel Obrist;Direct measurements of gaseous elemental mercury (GEM) exchanges over global ecosystems are challenging and require extensive and costly measurement systems. Here, we explore the use of atmospheric GEM concentration variability and passive samplers to assess underlying ecosystem GEM exchanges at two rural temperate forests in the northeastern United States. We find strong temporal alignments between atmospheric GEM concentration declines and ecosystem GEM deposition in spring at both forests, which followed patterns of CO
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.2139/ssrn.4481271&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routeshybrid 0 citations 0 popularity Average influence Average impulse Average Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.2139/ssrn.4481271&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Preprint , Other literature type 2020Publisher:Copernicus GmbH Funded by:NSF | Collaborative Research: G..., EC | BYONIC, NSF | GEOTRACES Arctic Section:... +5 projectsNSF| Collaborative Research: GEOTRACES Arctic Section: Marine Cycling of Bioactive Trace Metals in the Arctic Ocean ,EC| BYONIC ,NSF| GEOTRACES Arctic Section: Shipboard determination of key trace elements ,NSF| US GEOTRACES PMT: Cobalt Biogeochemical Cycling and Connections to Metalloenzymes in the Pacific Ocean ,NSF| Collaborative Research: Biogeochemical Cycling of Particulate Trace Elements in the Western Arctic Basin ,NSF| Collaborative Research: Underexplored connections between nitrogen and trace metal cycling in oxygen minimum zones mediated by metalloenzyme inventories ,NSERC ,NSF| GEOTRACES Arctic Section: Collaborative Research: Biogeochemical cycling of particulate trace elements in the western Arctic basinRandelle M. Bundy; Alessandro Tagliabue; Nicholas J. Hawco; Peter L. Morton; Benjamin S. Twining; Mariko Hatta; Abigail E. Noble; Mattias R. Cape; Seth G. John; Jay T. Cullen; Mak A. Saito;Cobalt (Co) is an important bioactive trace metal that is the metal cofactor in cobalamin (vitamin B12) which can limit or co-limit phytoplankton growth in many regions of the ocean. Total dissolved and labile Co measurements in the Canadian sector of the Arctic Ocean during the U.S. GEOTRACES Arctic expedition (GN01) and the Canadian International Polar Year GEOTRACES expedition (GIPY14) revealed a dynamic biogeochemical cycle for Co in this basin. The major sources of Co in the Arctic were from shelf regions and rivers, with only minimal contributions from other freshwater sources (sea ice, snow) and eolian deposition. The most striking feature was the extremely high concentrations of dissolved Co in the upper 100 m, with concentrations routinely exceeding 800 pmol L−1 over the shelf regions. This plume of high Co persisted throughout the Arctic basin and extended to the North Pole, where sources of Co shifted from primarily shelf-derived to riverine, as freshwater from Arctic rivers was entrained in the Transpolar Drift. Dissolved Co was also strongly organically complexed in the Arctic, ranging from 70 % to 100 % complexed in the surface and deep ocean, respectively. Deep-water concentrations of dissolved Co were remarkably consistent throughout the basin (∼55 pmol L−1), with concentrations reflecting those of deep Atlantic water and deep-ocean scavenging of dissolved Co. A biogeochemical model of Co cycling was used to support the hypothesis that the majority of the high surface Co in the Arctic was emanating from the shelf. The model showed that the high concentrations of Co observed were due to the large shelf area of the Arctic, as well as to dampened scavenging of Co by manganese-oxidizing (Mn-oxidizing) bacteria due to the lower temperatures. The majority of this scavenging appears to have occurred in the upper 200 m, with minimal additional scavenging below this depth. Evidence suggests that both dissolved Co (dCo) and labile Co (LCo) are increasing over time on the Arctic shelf, and these limited temporal results are consistent with other tracers in the Arctic. These elevated surface concentrations of Co likely lead to a net flux of Co out of the Arctic, with implications for downstream biological uptake of Co in the North Atlantic and elevated Co in North Atlantic Deep Water. Understanding the current distributions of Co in the Arctic will be important for constraining changes to Co inputs resulting from regional intensification of freshwater fluxes from ice and permafrost melt in response to ongoing climate change.
add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.5194/bg-2020-84&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess Routesgold 17 citations 17 popularity Top 10% influence Average impulse Top 10% Powered by BIP!more_vert add ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.5194/bg-2020-84&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eudescription Publicationkeyboard_double_arrow_right Article , Preprint 2009Publisher:IOP Publishing Funded by:NSERCNSERCDaigle, Olivier; Carignan, Claude; Gach, Jean-Luc; Guillaume, Christian; Lessard, Simon; Fortin, Charles-Anthony; Blais-Ouellette, Sebastien;An EMCCD camera, designed from the ground up for extreme faint flux imaging, is presented. CCCP, the CCD Controller for Counting Photons, has been integrated with a CCD97 EMCCD from e2v technologies into a scientific camera at the Laboratoire d'Astrophysique Exp\'erimentale (LAE), Universit\'e de Montr\'eal. This new camera achieves sub-electron read-out noise and very low Clock Induced Charge (CIC) levels, which are mandatory for extreme faint flux imaging. Data gathered with the camera suggests that through enhanced manufacturing processes, which would avoid traps from being created, and with the help of the clock shapes producible with CCCP, the CIC generated during the vertical transfer could be virtually suppressed. The camera has been characterized in laboratory and used on the Observatoire du Mont M\'egantic 1.6-m telescope. The performance of the camera is discussed and experimental data with the first scientific data are presented. Comment: 11 pages, 5 figures, Proceedings of the Detectors for Astronomy 2009 conference
Publications of the ... arrow_drop_down https://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: DatacitePublications of the Astronomical Society of the PacificArticle . 2009 . Peer-reviewedData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1086/605449&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.euAccess RoutesGreen bronze 37 citations 37 popularity Top 10% influence Top 10% impulse Top 10% Powered by BIP!more_vert Publications of the ... arrow_drop_down https://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: DatacitePublications of the Astronomical Society of the PacificArticle . 2009 . Peer-reviewedData sources: Crossrefhttps://doi.org/10.48550/arxiv...Article . 2009License: arXiv Non-Exclusive DistributionData sources: Dataciteadd ClaimPlease grant OpenAIRE to access and update your ORCID works.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.This Research product is the result of merged Research products in OpenAIRE.
You have already added works in your ORCID record related to the merged Research product.All Research productsarrow_drop_down <script type="text/javascript"> <!-- document.write('<div id="oa_widget"></div>'); document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=10.1086/605449&type=result"></script>'); --> </script>
For further information contact us at helpdesk@openaire.eu