Trace elements and Polycyclic Aromatic Hydrocarbons (PAHs) in snow and ice sampled at Colle Gnifetti, Monte Rosa (4450 m), during the last 10,000 years: environmental and climatic implications

• Main Author: Gabrieli, Jacopo
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Joseph-Fourier - Grenoble I, Claude Boutron([e-mail]), PSI, Villigen (CH), LGGE, Grenoble, University ca' Foscari, Venice (Italy)
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2008
• Subjects: alps; ice core; heavy metals; POPs; PAHs; Colle Gnifetti; [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology
• Online Access: https://theses.hal.science/tel-00407177; https://theses.hal.science/tel-00407177/document; https://theses.hal.science/tel-00407177/file/Gabrieli_PhD_thesis_Colle_Gnifetti.pdf

A new melting device for on-line decontamination and continuous analysis of alpine firn/ice cores has been designed, built and tested. Melt water from the inner part of each ice core section was pumped to an ICP-QMS and a conductivity micro-cell for continuous measurements of trace elements concentrations and conductivity, respectively. Discrete samples were also collected for trace elements, Pb isotopes and 239Pu determinations by ICP-SFMS and ICP-OES. Melt water from the outer section was extracted on-line by solid-phase cartridges for semi-continuous Polycyclic Aromatic Hydrocarbons (PAHs) analysis. Pronounced seasonal variations were observed for all elements, both crustal (Mg, Al) and anthropogenically enriched (Pb). To understand short-time variations, air mass back trajectories are an important parameter which must be considered. Also the knowledge of the temperature inversion dynamics and the boundary layer features is extremely important because they play a key role in the transport and dispersion of aerosol and gases from low-altitude emission sources. The largest emissions of Pb through history occurred during the 19th and 20th centuries and especially between the 1950s and 1970s. To determine if changes observed in Colle Gnifetti core faithfully reflect changes in emissions from nearby European countries, we have compared snow/ice data with emissions data present in the literature. For example, from 1800 AD to the first decade of 20th century Pb concentrations progressively increased, reaching a maximum in the 1920s. During the 1920s Pb concentrations suddenly halved and remained low for the next two decades. After the Second World War, Pb depositions increased dramatically with the introduction of Pb additives in gasoline, peaking in the mid-1970s. From 1975, Pb concentrations in Colle Gnifetti ice began to decrease in accordance with the first environmental policies in Europe which started to limit pollutant emissions. Before 1875 PAHs levels were very low: the pre-1750's PAHs concentrations were ...