Quaternary variations and origin of continental dust in East antarctica

• Main Author: Delmonte, Barbara
• 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), Università degli studi di Milano-Bicocca, Jean Robert Petit; Valter Maggi
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2003
• Subjects: aérosols minéraux continentaux; carootte glaciaire; Dome B; Vostok; Komsomolskaia; signature isotopique; interglaciaires; Holocène; propagation circumpolaire; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDV.EE.BIO]Life Sciences [q-bio]/Ecology; environment/Bioclimatology; Antarctic; The Antarctic; East Antarctica; Patagonia; Antarc*; Antarctica; Antarctique*; EPICA; ice core
• Online Access: https://theses.hal.science/tel-00701343; https://theses.hal.science/tel-00701343/document; https://theses.hal.science/tel-00701343/file/These-Delmonte-2003.pdf

The mineral dust of continental origin windblown to the East Antarctic Plateau has been studied for its geographical provenance and variability during the Quaternary. Four deep ice cores [EPICA-Dome C (75° 06'S, 123° 21'E), Dome B (77° 05' S, 94° 55' E), Vostok (78° S, 106° E) and Komsomolskaia (74° 05' S, 97° 29' E) have been investigated. Dust provenance in glacial and interglacial epochs has been identified through the 87Sr/86Sr versus 143Nd/144Nd isotopic signature of ice core dust and sediments from the Potential Source Areas (PSA) of the Southern Hemisphere. The isotopic method has been refined with respect to previous studies. Dust concentration and size distribution measurements have been performed at high temporal resolution in order to examine the long-term and short-term variability of dust flux, from which important information about the conditions at the source region(s), the hydrological cycle and the transport patterns can be inferred. For all East Antarctic sites investigated, dust originates from the southern South American regions of the Pampas and Patagonia in glacial times, but during warm interglacial periods an additional source probably contributed. The dust input also has proved to be remarkably similar between the different sites, and shows clear relationship with environmental conditions at the source regions. However, such an apparent uniformity of dust flux nests striking differences in dust transport, particularly during the Last Glacial Maximum. The reorganization of atmospheric circulation in the circumantarctic during the last climatic transition generated asynchronous and even opposite changes in transport patterns in different sectors of the Antarctic Plateau. During the Deglaciation and the Holocene epochs, millennial and secular scale pulsations in dust advection to the Plateau are omnipresent. From site to site, periodicities are the same but the phasing of the variations is different. Such rhythm suggests a circumpolar displacement of ocean-sea iceatmosphere anomalies at ...