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Jordan TA, Martin C, Ferraccioli F, Matsuoka K, Corr H, Forsberg R, Olesen A, Siegert M. Anomalously high geothermal flux near the South Pole. Sci Rep 2018; 8:16785. [PMID: 30429526 PMCID: PMC6235973 DOI: 10.1038/s41598-018-35182-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 10/31/2018] [Indexed: 11/18/2022] Open
Abstract
Melting at the base of the Antarctic Ice Sheet influences ice dynamics and our ability to recover ancient climatic records from deep ice cores. Basal melt rates are affected by geothermal flux, one of the least constrained properties of the Antarctic continent. Estimates of Antarctic geothermal flux are typically regional in nature, derived from geological, magnetic or seismic data, or from sparse point measurements at ice core sites. We analyse ice-penetrating radar data upstream of South Pole revealing a ~100 km long and 50 km wide area where internal ice sheet layers converge with the bed. Ice sheet modelling shows that this englacial layer configuration requires basal melting of up to 6 ± 1 mm a-1 and a geothermal flux of 120 ± 20 mW m-2, more than double the values expected for this cratonic sector of East Antarctica. We suggest high heat producing Precambrian basement rocks and hydrothermal circulation along a major fault system cause this anomaly. We conclude that local geothermal flux anomalies could be more widespread in East Antarctica. Assessing their influence on subglacial hydrology and ice sheet dynamics requires new detailed geophysical observations, especially in candidate areas for deep ice core drilling and at the onset of major ice streams.
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Affiliation(s)
- T A Jordan
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
| | - C Martin
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - F Ferraccioli
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - K Matsuoka
- Norwegian Polar Institute, Tromsø, Norway
| | - H Corr
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - R Forsberg
- National Space Institute, Technical University of Denmark, Lyngby, Denmark
| | - A Olesen
- National Space Institute, Technical University of Denmark, Lyngby, Denmark
| | - M Siegert
- Grantham Institute and Department of Earth Sciences and Engineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
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Scheinert M, Ferraccioli F, Schwabe J, Bell R, Studinger M, Damaske D, Jokat W, Aleshkova N, Jordan T, Leitchenkov G, Blankenship DD, Damiani TM, Young D, Cochran JR, Richter TD. New Antarctic Gravity Anomaly Grid for Enhanced Geodetic and Geophysical Studies in Antarctica. Geophys Res Lett 2016; 43:600-610. [PMID: 29326484 PMCID: PMC5759340 DOI: 10.1002/2015gl067439] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km2, which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated levelling of the different gravity datasets with respect to an Earth Gravity Model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth Gravity Models to be derived and represent a major step forward towards solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica.
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Affiliation(s)
- M. Scheinert
- Institut für Planetare Geodäsie, Technische Universität Dresden, Dresden, Germany
| | - F. Ferraccioli
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, UK
| | - J. Schwabe
- Institut für Planetare Geodäsie, Technische Universität Dresden, Dresden, Germany
| | - R. Bell
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | | | - D. Damaske
- Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover, Germany
| | - W. Jokat
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
- University of Bremen, Geoscience, Department, Bremen, Germany
| | | | - T. Jordan
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, UK
| | - G. Leitchenkov
- VNIIOkeangeologia, St. Petersburg, Russia
- St. Petersburg State University, St. Petersburg, Russia
| | - D. D. Blankenship
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, TX, USA
| | - T. M. Damiani
- National Geodetic Survey, NOAA, Silver Spring, MD, USA
| | - D. Young
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, TX, USA
| | - J. R. Cochran
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - T. D. Richter
- Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, TX, USA
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Bell RE, Ferraccioli F, Creyts TT, Braaten D, Corr H, Das I, Damaske D, Frearson N, Jordan T, Rose K, Studinger M, Wolovick M. Widespread Persistent Thickening of the East Antarctic Ice Sheet by Freezing from the Base. Science 2011; 331:1592-5. [DOI: 10.1126/science.1200109] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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