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Hill, D.
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Hill, D.
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- 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 - 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