Search results for "Geophysic"
showing 10 items of 2684 documents
Heating glaciers from below
2013
Climate change is affecting the cryosphere from above. Geothermal heat flux from below is also contributing to conditions at the base of Greenland's ice sheet, which sits atop a lithosphere of variable thickness.
Modeling of biomass smoke injection into the lower stratosphere by a large forest fire (Part II): Sensitivity studies
2006
Abstract. The Chisholm forest fire that burned in Alberta, Canada, in May 2001 resulted in injection of substantial amounts of smoke into the lower stratosphere. We used the cloud-resolving plume model ATHAM (Active Tracer High resolution Atmospheric Model) to investigate the importance of different contributing factors to the severe intensification of the convection induced by the Chisholm fire and the subsequent injection of biomass smoke into the lower stratosphere. The simulations show strong sensitivity of the pyro-convection to background meteorology. This explains the observed coincidence of the convective blow-up of the fire plume and the passage of a synoptic cold front. Furthermor…
Nitrogen isotopes in tooth enamel record diet and trophic level enrichment: results from a controlled feeding experiment
2021
Nitrogen isotope ratios (δ15N) are a well-established tool for investigating the dietary and trophic behavior of animals in terrestrial and marine food webs. To date, δ15N values in fossils have primarily been measured in collagen extracted from bone or dentin, which is susceptible to degradation and rarely preserved in deep time (>100,000 years). In contrast, tooth enamel organic matter is protected from diagenetic alteration by the mineral structure of hydroxyapatite and thus is often preserved over geological time. However, due to the low nitrogen content (<0.01 %) of enamel, the measurement of its nitrogen isotopic composition has been prevented by the analytical limit…
Carbon isotope stratigraphy, magnetostratigraphy, and 40Ar/39Ar age of the Cretaceous South Atlantic coast, Namibe Basin, Angola
2014
This publication results from Projecto PaleoAngola, an international cooperative research effort among the contributing authors and their institutions, funded by the National Geographic Society, the Petroleum Research Fund of the American Chemical Society, Sonangol E.P., Esso Angola, Fundacao Vida of Angola, LS Films, Maersk, Damco, Safmarine, ISEM at SMU, The Royal Dutch Embassy in Luanda, TAP Airlines, Royal Dutch Airlines, The Saurus Institute, and the Perot Museum of Nature and Science. JS was additionally funded by Yale University and the Alfred Kordelin Foundation. We dedicate this contribution to the late Kalunga Lima, our friend and colleague in Projecto PaleoAngola. We thank Margar…
"Table 22" of "Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV"
2020
$\phi$ transverse momentum spectrum - V0M multiplicity class IV
"Table 32" of "Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV"
2020
$\phi$ transverse momentum spectrum ratio to INEL>0 - V0M multiplicity class IV
One-dimensional compression and consolidation of shales
2016
This paper presents a comprehensive methodology for analysing the compression and consolidation behaviour of shales. An apparatus was designed to perform oedometric high-pressure tests by applying a maximum vertical total stress of 100 MPa and simultaneously controlling the pore water pressure of the specimen. An analytical method was formulated to analyse the shale consolidation behaviour, which allows information to be gathered on the coefficient of consolidation, stiffness, poroelastic properties, secondary compression and permeability of the tested material as a function of the applied stress conditions. Results obtained on Opalinus Clay shale using the developed methodology are present…
Nouveaux biohorizons et propositions pour le découpage biozonal ammonitique du Barrémien supérieur du Sud-Est de la France
2008
International audience; Un nouveau découpage biozonal ammonitique du Barrémien supérieur du Sud-Est de la France est proposé. Il tient compte des renouvellements fauniques, des données séquentielles ainsi que des données historiques. Il est enrichi de quatre biohorizons nouveaux. Le Barrémien supérieur comporte à présent les trois biozones (anciennement six) à Vandenheckei, Sartousiana et Giraudi. La première contient les trois sous-zones à Uhligi, dont le statut est discuté, Sayni et Barremense, ainsi que les deux nouveaux biohorizons à Marchandi et Breistrofferi (sommet de la Sous-Zone à Barremense). La Biozone à Sartousiana admet les sous-zones à Limentinus, Provincialis et Feraudianus. …
Satellite Observations of the Contrasting Response of Trees and Grasses to Variations in Water Availability
2019
Interannual variations in ecosystem primary productivity are dominated by water availability. Until recently, characterizing the photosynthetic response of different ecosystems to soil moisture anomalies was hampered by observational limitations. Here, we use a number of satellite-based proxies for productivity, including spectral indices, sun-induced chlorophyll fluorescence, and data-driven estimates of gross primary production, to reevaluate the relationship between terrestrial photosynthesis and water. In contrast to nonwoody vegetation, we find a resilience of forested ecosystems to reduced soil moisture. Sun-induced chlorophyll fluorescence and data-driven gross primary production ind…
Preface: Environmental benefits of biochar
2014
J. Paz-Ferreiro1, A. Mendez6, A. M. Tarquis3,4, A. Cerda5, and G. Gasco2 1School of Civil, Environmental and Chemical Engineering, RMIT University, GPO Box 2476, Melbourne 3001, VIC, Melbourne, Australia 2Departamento de Produccion Agraria, E.T.S.I. Agronomos, Universidad Politecnica de Madrid, Ciudad Universitaria, 28004 Madrid, Spain 3CEIGRAM, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain 4Departamento de Matematica Aplicada, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain 5Soil Erosion and Degradation Research Group, Department of Geography, University of Valencia, C/Blasco Ibanez 10, 46010 Valencia, Spain 6Departamento de Ingen…