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Geological Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
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- PublicationRestrictedMiddle Miocene to Pliocene History of Antarctica and the Southern Ocean(2008)
; ; ; ; ; ; ; ; ; ; ; ; ; ;Haywood, A. M.; School of Earth & Environment, University of Leeds, Leeds LS2 9JT, UK ;Smellie, J. L.; Geological Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK ;Ashworth, A. C.; Department of Geosciences, North Dakota State University, Fargo, ND 58105-5517, USA ;Cantrill, D. J.; Royal Botanic Gardens Melbourne, Private Bag 2000, Birdwood Avenue, South Yarra, Victoria 3141, Australia ;Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Hambrey, M. J.; Institute of Geography & Earth Sciences, University of Wales, Aberystwyth, Ceredigion SY23 3DB, UK ;Hill, D.; Geological Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK ;Hillenbrand, C.-D.; Geological Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK ;Hunter, S. J.; Geological Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK and School of Earth & Environment, University of Leeds, Leeds LS2 9JT, UK ;Larter, R. D.; Geological Sciences Division, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK ;Lear, C. H.; School of Earth, Ocean and Planetary Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK ;Passchier, S.; Department of Earth and Environmental Studies, Mallory Hall 252, Montclair State University, Montclair, NJ 07043, USA ;van de Wal, R.; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584 Utrecht, The Netherlands; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Siegert, M.; School of GeoSciences, Grant Institute, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JW, UK; This chapter explores the Middle Miocene to Pliocene terrestrial and marine records of Antarctica and the Southern Ocean. The structure of the chapter makes a clear distinction between terrestrial and marine records as well as proximal (on or around Antarctica) and more distal records (Southern Ocean). Particular geographical regions are identified that reflect the areas for which the majority of palaeoenvironmental and palaeoclimatic information exist. Specifically, the chapter addresses the terrestrial sedimentary and fjordal environments of the Transantarctic Mountains and Lambert Glacier region, the terrestrial fossil record of Antarctic climate, terrestrial environments of West Antarctica, and the marine records of the East Antarctic Ice Sheet (EAIS), the West Antarctic Ice Sheet (WAIS) and the Antarctic Peninsula Ice Sheet (APIS), as well as the marine record of the Southern Ocean. Previous and current studies focusing on modelling Middle Miocene to Pliocene climate, environments and ice sheets are discussed.162 32 - PublicationRestrictedEvidence for the contemporary magmatic system beneath Long Valley Caldera from local earthquake tomography and receiver function analysis(2011)
; ; ; ; ; ;Seccia, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Chiarabba, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;De Gori, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Bianchi, I.; Institut für Meteorologie und Geophysik, Universität Wien, Vienna, Austria ;Hill, D.; U.S. Geological Survey, Menlo Park, California, USA; ; ; ; We present a new P wave and S wave velocity model for the upper crust beneath Long Valley Caldera obtained using local earthquake tomography and receiver function analysis. We computed the tomographic model using both a graded inversion scheme and a traditional approach. We complement the tomographic Vp model with a teleseismic receiver function model based on data from broadband seismic stations (MLAC and MKV) located on the SE and SW margins of the resurgent dome inside the caldera. The inversions resolve (1) a shallow, high‐velocity P wave anomaly associated with the structural uplift of a resurgent dome; (2) an elongated, WNW striking low‐velocity anomaly (8%–10 % reduction in Vp) at a depth of 6 km (4 km below mean sea level) beneath the southern section of the resurgent dome; and (3) a broad, low‐velocity volume (∼5% reduction in Vp and as much as 40% reduction in Vs) in the depth interval 8–14 km (6–12 km below mean sea level) beneath the central section of the caldera. The two low‐velocity volumes partially overlap the geodetically inferred inflation sources that drove uplift of the resurgent dome associated with caldera unrest between 1980 and 2000, and they likely reflect the ascent path for magma or magmatic fluids into the upper crust beneath the caldera.161 46 - PublicationOpen AccessVolcanism in Antarctica: An assessment of the present state of research and future directions(2023-12)
; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ; ;; ;Over the past decades, significant efforts have been made to understand the nature, dynamics and evolution of volcanic systems. In parallel, the continuous demographic expansion and extensive urbanization of volcanic areas have increased the exposure of our society to these natural phenomena. This increases the need to improve our capacities to accurately assess projected volcanic hazards and their potential socioeconomic and environmental impact, and Antarctica and the sub-Antarctic islands are no exception. More than a hundred volcanoes have been identified in Antarctica, some of which are entirely buried beneath the ice sheet and others as submarine volcanoes. Of these, at least eight large (basal diameters > c. 20-30 km) volcanoes are known to be active and pose a considerable threat to scientific and ever-increasing tourism activities being carried out in the region. Despite the scientific and socioeconomic interest, many aspects of the past volcanic activity and magmatic processes in Antarctica, and current volcanic hazards and risks, remain unknown. Moreover, many of Antarctica’s volcanoes preserve a remarkable history of the eruptive environment, from which multiple parameters of past configurations of the Antarctic ice sheet (AIS) can be deduced. Given the critical role that the AIS plays in regulating Earth’s climate, Antarctica’s volcanoes therefore can be regarded as the ground truth for current models of past climates derived from modelling and studies of marine sediments. Here, we provide a succinct overview of the evolution of volcanism and magmatism in Antarctica and the sub-Antarctic region over the past 200 million years. Then, we briefly review the current state of knowledge of the most crucial aspects regarding Antarctica’s volcanic and magmatic processes, and the contributions volcanic studies have made to our understanding of ice sheet history and evolution, geothermal heat flow, as well as present-day and future volcanic hazard and risk. A principal objective is to highlight the problems and critical limitations of the current state of knowledge and to provide suggestions for future potential directions of volcanic-driven investigations in Antarctica. Finally, we also discuss and assess the importance and scope of education and outreach activities specifically relating to Antarctic volcanism, and within the context of broader polar sciences.89 26