DOCSLIB.ORG

Polar Remote Sensing Volume II: Ice Sheets

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Polar Remote Sensing Volume II: Ice Sheets www.GISman.ir Polar Remote Sensing Volume II: Ice Sheets www.GISman.ir Robert Massom and Dan Lubin Polar Remote Sensing Volume II: Ice Sheets Published in association with Praxis Publishing Chichester, UK www.GISman.ir Dr. Robert Massom Senior Research Scientist and Lecturer Antarctic Climate and Ecosystems Cooperative Research Centre University of Tasmania Sandy Bay Tasmania Australia Dr. Dan Lubin Research Physicist and Senior Lecturer Scripps Institution of Oceanography University of California, San Diego La Jolla California USA SPRINGER±PRAXIS BOOKS IN GEOPHYSICAL SCIENCES Published in association with Antarctic Climate and Ecosystems Cooperative Research Centre, Australia SUBJECT ADVISORY EDITOR: Dr. Philippe Blondel, C.Geol., F.G.S., Ph.D., M.Sc., Senior Scientist, Department of Physics, University of Bath, Bath, UK ISBN 3-540-26101-X Springer-Verlag Berlin Heidelberg New York Springer is part of Springer-Science + Business Media (springeronline.com) Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliogra®e; detailed bibliographic data are available from the Internet at http://dnb.ddb.de Library of Congress Control Number: 20059276101 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. # Praxis Publishing Ltd, Chichester, UK, 2006 Printed in Germany The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a speci®c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: Jim Wilkie Project management: Originator Publishing Services, Gt Yarmouth, Norfolk, UK Printed on acid-free paper www.GISman.ir Contents Preface ............................................. ix List of ®gures ........................................ xiii List of tables ......................................... xxi List of abbreviations .................................... xxiii About the author....................................... xxix Publisher credits ....................................... xxxi 1 Polar ice sheets: Introduction 1 1.1 The global importance of polar ice sheets................ 1 1.2 Ice-sheet mass balanceÐbackground information ........... 10 1.2.1 Comparative characteristics of the Greenland and Antarctic Ice Sheets ........................ 16 1.2.2 Approaches to the measurement of ice-sheet mass balance 16 1.3 The recent revolution in satellite remote sensing ........... 21 1.4 References .................................... 24 2 Synthetic aperture radar interferometry and related techniques ....... 39 2.1 Introduction and background........................ 39 2.2 Underlying principles and terminology of InSAR........... 41 2.2.1 The basis of ice sheet surface elevation and motion measurement by satellite repeat-pass interferometry .... 46 2.2.2 Measurement of ice-surface displacement/motion ...... 50 2.2.3 What is an interferogram? .................... 54 2.3 Inherent constraints and sources of ambiguity and error ...... 55 2.3.1 Thermal decorrelation ....................... 56 2.3.2 Temporal decorrelation ...................... 57 www.GISman.ir vi Contents 2.3.3 Decorrelation due to excessive target motion/rotation. 59 2.3.4 Atmospheric and ionospheric propagation delay ...... 60 2.3.5 Baseline (spatial) decorrelation.................. 62 2.3.6 Volume decorrelation, and ambiguities relating to radar penetration depth and volume scattering ........... 63 2.3.7 Image speckle............................. 66 2.3.8 Geometric distortions and steep terrain effects ....... 67 2.3.9 Estimation of phase decorrelation . .............. 67 2.3.10 Processing errors and other sources of ambiguity ..... 70 2.3.11 Summary of baseline-related trade-offs ............ 70 2.4 Satellite-SAR interferometric data requirements and processing steps ........................................ 71 2.4.1 Selection of suitable SAR images . .............. 74 2.4.2 Geometric co-registration ..................... 81 2.4.3 Pre-processing and interferogram generation......... 82 2.4.4 Phase unwrapping .......................... 84 2.4.5 Phase-to-height conversion .................... 89 2.4.6 Interferogram geo-coding ..................... 89 2.5 The measurement of ice-sheet elevation and surface velocity using differential InSAR techniques........................ 90 2.5.1 Ice-sheet topography from DInSAR .............. 92 2.5.2 Retrieval of ice-sheet surface motion.............. 93 2.5.3 Tidal effects on InSAR retrievals over ¯oating ice ..... 101 2.6 Ice-sheet surface motion retrieval by speckle tracking ........ 101 2.7 Ice-sheet surface motion retrieval by coherence tracking ...... 108 2.8 Relative strengths and weaknesses of differential InSAR, coher- ence tracking, and intensity tracking ................... 109 2.9 Polarimetric Interferometric SAR (Pol-InSAR) ............ 111 2.10 Developments and outstanding issues .................. 112 2.11 References .................................... 116 3Satellite remote sensing of ice sheet parameters and processes ....... 137 3.1 Introduction ................................... 137 3.2 Improved detection and mapping of surface features ........ 137 3.2.1 High-resolution visible±thermal infrared methods...... 137 3.2.2 Moderate-resolution visible/thermal infrared ......... 145 3.2.3 Synthetic aperture radar ...................... 151 3.2.4 The mapping of ice-sheet facies . .............. 158 3.3 Detection, mapping and monitoring of ice-sheet surface melt and refreezing ..................................... 164 3.3.1 Visible and thermal infrared techniques ............ 164 3.3.2 Active-microwave techniques ................... 166 3.3.3 Passive-microwave techniques .................. 169 3.3.4 Estimation of surface melt rates. .............. 174 3.4 Detection and mapping of changes in ice-sheet margins ...... 175 3.4.1 The collapse of the Larsen Ice Shelf .............. 177 www.GISman.ir Contents vii 3.4.2 Examples of recent change in the con®guration of other glacier systems . .......................... 183 3.5 Icebergs...................................... 186 3.5.1 Iceberg detection and size statistics............... 186 3.5.2 Monitoring iceberg drift ...................... 199 3.5.3 Measurement of iceberg thickness................ 206 3.6 Measurement of ice sheet topography/elevation and change in elevation ..................................... 209 3.6.1 Surface elevation from satellite radar altimetry ....... 211 3.6.2 Surface elevation from laser altimetry ............. 229 3.6.3 Improved digital elevation model construction using satel- lite image-based photoclinometry ................ 234 3.6.4 Surface elevation from SAR interferometry (InSAR) . 237 3.7 Accumulation rate ............................... 240 3.8 Ice velocity, strain rate, and balance velocity/¯ux ........... 247 3.8.1 Feature tracking . .......................... 250 3.8.2 SAR interferometry and ice velocity .............. 257 3.8.3 Balance velocities and ¯uxes ................... 265 3.8.4 Strain rates .............................. 268 3.8.5 Detection of variability in ice ¯ow and surge behavior . 271 3.8.6 Ice shelf buttressing, and the impact of ice shelf removal on outlet glaciers .......................... 274 3.9 Tidal displacement of ice shelves and glacier tongues ........ 276 3.10 Grounding-line (zone) detection and monitoring ........... 279 3.11 Estimates of ice discharge ¯ux and basal melt/freeze rates ..... 281 3.12 The measurement of changes in ice mass by satellite gravity sensors ...................................... 288 3.13 The radar sounding of ice sheets from space.............. 289 3.14 Ice-sheet surface temperature ........................ 291 3.14.1 Thermal infrared techniques ................... 292 3.14.2 Passive-microwave techniques .................. 295 3.15 Ice sheet surface albedo . .......................... 299 3.16 Grain size, impurity content, and surface to near-surface characteristics .................................. 309 3.16.1 Snow-grain size and impurity content ............. 309 3.16.2 Changes in snow/®rn characteristics inferred from passive- microwave data . .......................... 312 3.16.3 Ice sheet roughness characteristics and proxy wind meas- urements ................................ 315 3.16.4 Active-microwave remote sensing of ice-sheet surface and near-surface characteristics .................... 318 3.17 Conclusions ................................... 321 3.18 References .................................... 323 Appendix............................................ 387 Index .............................................. 397 www.GISman.ir Preface The objective of this two-volume book is to survey one of the most challenging and at the same time most necessary applications of satellite remote sensing: geophysical sciences in the Earth's polar regions. Much has happened in this ®eld over the past decade. In addition to dedicated satellite instruments and programs that have monitored critical
Load more

Recommended publications
  • Dustin M. Schroeder
    Dustin M. Schroeder Assistant Professor of Geophysics Department of Geophysics, School of Earth, Energy, and Environmental Sciences 397 Panama Mall, Mitchell Building 361, Stanford University, Stanford, CA 94305 [email protected], 440.567.8343 EDUCATION 2014 Jackson School of Geosciences, University of Texas, Austin, TX Doctor of Philosophy (Ph.D.) in Geophysics 2007 Bucknell University, Lewisburg, PA Bachelor of Science in Electrical Engineering (B.S.E.E.), departmental honors, magna cum laude Bachelor of Arts (B.A.) in Physics, magna cum laude, minors in Mathematics and Philosophy PROFESSIONAL EXPERIENCE 2016 – present Assistant Professor of Geophysics, Stanford University 2017 – present Assistant Professor (by courtesy) of Electrical Engineering, Stanford University 2020 – present Center Fellow (by courtesy), Stanford Woods Institute for the Environment 2020 – present Faculty Affiliate, Stanford Institute for Human-Centered Artificial Intelligence 2021 – present Senior Member, Kavli Institute for Particle Astrophysics and Cosmology 2016 – 2020 Faculty Affiliate, Stanford Woods Institute for the Environment 2014 – 2016 Radar Systems Engineer, Jet Propulsion Laboratory, California Institute of Technology 2012 Graduate Researcher, Applied Physics Laboratory, Johns Hopkins University 2008 – 2014 Graduate Researcher, University of Texas Institute for Geophysics 2007 – 2008 Platform Hardware Engineer, Freescale Semiconductor SELECTED AWARDS 2021 Symposium Prize Paper Award, IEEE Geoscience and Remote Sensing Society 2020 Excellence in Teaching Award, Stanford School of Earth, Energy, and Environmental Sciences 2019 Senior Member, Institute of Electrical and Electronics Engineers 2018 CAREER Award, National Science Foundation 2018 LInC Fellow, Woods Institute, Stanford University 2016 Frederick E. Terman Fellow, Stanford University 2015 JPL Team Award, Europa Mission Instrument Proposal 2014 Best Graduate Student Paper, Jackson School of Geosciences 2014 National Science Olympiad Heart of Gold Award for Service to Science Education 2013 Best Ph.D.
    [Show full text]
  • Englacial Architecture and Age‐Depth Constraints Across 10.1029/2019GL086663 the West Antarctic Ice Sheet Key Points: David W
    RESEARCH LETTER Englacial Architecture and Age‐Depth Constraints Across 10.1029/2019GL086663 the West Antarctic Ice Sheet Key Points: David W. Ashmore1 , Robert G. Bingham2 , Neil Ross3 , Martin J. Siegert4 , • We measure and date individual 5 1 isochronal radar internal reflection Tom A. Jordan , and Douglas W. F. Mair horizons across the Weddell Sea 1 2 sector of the West Antarctic Ice School of Environmental Sciences, University of Liverpool, Liverpool, UK, School of GeoSciences, University of Sheet Edinburgh, Edinburgh, UK, 3School of Geography, Politics and Sociology, Newcastle University, Newcastle upon Tyne, • – – Horizons dated to 1.9 3.2, 3.5 6.0, UK, 4Grantham Institute and Department of Earth Science and Engineering, Imperial College London, London, UK, and 4.6–8.1 ka are widespread and 5British Antarctic Survey, Cambridge, UK linked to previous radar surveys of the Ross and Amundsen Sea sectors • These form the basis for a wider database of ice sheet architecture for Abstract The englacial stratigraphic architecture of internal reflection horizons (IRHs) as imaged by validating and calibrating ice sheet ice‐penetrating radar (IPR) across ice sheets reflects the cumulative effects of surface mass balance, basal models of West Antarctica melt, and ice flow. IRHs, considered isochrones, have typically been traced in interior, slow‐flowing regions. Here, we identify three distinctive IRHs spanning the Institute and Möller catchments that cover 50% of Supporting Information: • Supporting Information S1 West Antarctica's Weddell Sea Sector and are characterized by a complex system of ice stream tributaries. We place age constraints on IRHs through their intersections with previous geophysical surveys tied to Byrd Ice Core and by age‐depth modeling.
    [Show full text]
  • A Significant Acceleration of Ice Volume Discharge Preceded a Major Retreat of a West Antarctic Paleo–Ice Stream
    https://doi.org/10.1130/G46916.1 Manuscript received 26 August 2019 Revised manuscript received 23 November 2019 Manuscript accepted 26 November 2019 © 2019 Geological Society of America. For permission to copy, contact [email protected]. A signifcant acceleration of ice volume discharge preceded a major retreat of a West Antarctic paleo–ice stream Philip J. Bart1 and Slawek Tulaczyk2 1 Department of Geology and Geophysics, Louisiana State University, Baton Rouge, Louisiana 70803, USA 2 Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, California 95064, USA ABSTRACT SEDIMENT AND ICE DISCHARGE For the period between 14.7 and 11.5 cal. (calibrated) kyr B.P, the sediment fux of Bind- FROM THE PALEO–BINDSCHADLER schadler Ice Stream (BIS; West Antarctica) averaged 1.7 × 108 m3 a−1. This implies that BIS ICE STREAM velocity averaged 500 ± 120 m a−1. At a fner resolution, the data suggest two stages of ice Radiocarbon ages from benthic foramin- stream fow. During the frst 2400 ± 400 years of a grounding-zone stillstand, ice stream fow ifera (Bart et al., 2018) (Table 1) indicate that averaged 200 ± 90 m a−1. Following ice-shelf breakup at 12.3 ± 0.2 cal. kyr B.P., fow acceler- the paleo-BIS grounding line had retreated ated to 1350 ± 580 m a−1. The estimated ice volume discharge after breakup exceeds the bal- 70 km from its maximum (LGM) position by ance velocity by a factor of two and implies ice mass imbalance of −40 Gt a−1 just before the 14.7 ± 0.4 cal.
    [Show full text]
  • Ice-Flow Structure and Ice Dynamic Changes in the Weddell Sea Sector
    Bingham RG, Rippin DM, Karlsson NB, Corr HFJ, Ferraccioli F, Jordan TA, Le Brocq AM, Rose KC, Ross N, Siegert MJ. Ice-flow structure and ice-dynamic changes in the Weddell Sea sector of West Antarctica from radar-imaged internal layering. Journal of Geophysical Research: Earth Surface 2015, 120(4), 655-670. Copyright: ©2015 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. DOI link to article: http://dx.doi.org/10.1002/2014JF003291 Date deposited: 04/06/2015 This work is licensed under a Creative Commons Attribution 4.0 International License Newcastle University ePrints - eprint.ncl.ac.uk PUBLICATIONS Journal of Geophysical Research: Earth Surface RESEARCH ARTICLE Ice-flow structure and ice dynamic changes 10.1002/2014JF003291 in the Weddell Sea sector of West Antarctica Key Points: from radar-imaged internal layering • RES-sounded internal layers in Institute/Möller Ice Streams show Robert G. Bingham1, David M. Rippin2, Nanna B. Karlsson3, Hugh F. J. Corr4, Fausto Ferraccioli4, fl ow changes 4 5 6 7 8 • Ice-flow reconfiguration evinced in Tom A. Jordan , Anne M. Le Brocq , Kathryn C. Rose , Neil Ross , and Martin J. Siegert Bungenstock Ice Rise to higher 1 2 tributaries School of GeoSciences, University of Edinburgh, Edinburgh, UK, Environment Department, University of York, York, UK, • Holocene dynamic reconfiguration 3Centre for Ice and Climate, Niels Bohr Institute, University
    [Show full text]
  • Subglacial Lake Ellsworth CEE V2.Indd
    Proposed Exploration of Subglacial Lake Ellsworth Antarctica Draft Comprehensive Environmental Evaluation February 2011 1 The cover art was created by first, second, and third grade students at The Village School, a Montessori school located in Waldwick, New Jersey. Art instructor, Bob Fontaine asked his students to create an interpretation of the work being done on The Lake Ellsworth Project and to create over 200 of their own imaginary microbes. This art project was part of The Village School’s art curriculum that links art with ongoing cultural work. 2 Contents Non Technical Summary .................................................4 Personnel ............................................................................................ 26 Chapter 1: Introduction ...................................................6 Power generation and fuel calculations ....................................... 27 Chapter 2: Description of proposed activity..................7 Vehicles ................................................................................................ 28 Background and justification ..............................................................7 Water and waste ...............................................................................28 The site ...................................................................................................8 Communications ............................................................................... 28 Chapter 3: Baseline conditions of Lake Ellsworth .........9 Transport of equipment
    [Show full text]
  • Education Personal Research Interests Employment
    Douglas Reed MacAyeal Department of the Geophysical Sciences The University of Chicago 5734 S. Ellis Ave. HGS 424 Chicago, IL Phone: (773) 702-8027 (o) (773) 752-6078 (h) (773) 702-9505 (f) (224) 500-7775 (c) [email protected] [email protected] last updated: March, 2020 Education 1983 Ph.D. Princeton University, Princeton, NJ Geophysical Fluid Dynamics advisor: Kirk Bryan 1979 M.S. University of Maine, Orono, ME Physics/Glaciology advisor: Robert Thomas 1976 Sc.B. Brown University, Providence, RI Physics Magna cum laude, honors in physics Personal Birth Date: 8 December, 1954; Age: 65 Birth Place: Boston, MA, USA Marital Status: Married, Linda A. MacAyeal (Sparks) Children: Leigh C. (MacAyeal) Kasten (Brown U., Sc.B.; Cornell U., DVM), Hannah R. MacAyeal (U. Penn, B.S., U. Penn Veterinary Medicine, DVM), Evan C. MacAyeal (Carleton College, B.A., Columbia University, Financial Engineering, M.S.) Research Interests The physical processes that determine the evolution of ice and climate on Earth over the past, present and future. Employment Department of the Geophysical Sciences, University of Chicago 1983-Present Professor (Asst. until 1987, Assoc. until 1992 and Full until present) Prior to 1983: I was a graduate student at Princeton University and University of Maine. Awards and Honors • 2019 Seligman Crystal, International Glaciological Society (IGS) • 2013 Nye Lecture, American Geophysical Union (AGU), Fall Meeting • 2010 Goldthwait Award (Polar Medal) of the Byrd Polar Research Center, Ohio State University • 2005 Provost’s Teaching Award of the University of Chicago • 2002 Quantrell Teaching Award of the University of Chicago • 1997 Richardson Medal of the IGS • 1988 James Macelwane Medal of the AGU • 1988 Fellow of the AGU • Antarctic geographic names: MacAyeal Ice Stream, MacAyeal Peak Teaching Experience • GeoSci 242: Geophysical Fluid Dynamics, I.
    [Show full text]
  • Studies of Antarctic Ice Shelf Stability: Surface Melting, Basal Melting, and Ice Flow Dynamics
    Studies of Antarctic ice shelf stability: surface melting, basal melting, and ice flow dynamics by Karen E. Alley B.A., Colgate University, 2012 A thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirement for the degree of Doctor of Philosophy Department of Geological Sciences 2017 This thesis entitled: Studies of Antarctic ice shelf stability: Surface melting, basal melting, and ice flow dynamics written by Karen E. Alley has been approved for the Department of Geological Sciences James White Ted Scambos Date The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above-mentioned discipline. ii Alley, Karen Elizabeth (Ph.D., Department of Geological Sciences) Studies of Antarctic ice shelf stability: Surface melting, basal melting, and ice flow dynamics Thesis directed by Senior Research Scientist T.A. Scambos and Professor J.W.C. White Abstract: Floating extensions of ice sheets, known as ice shelves, play a vital role in regulating the rate of ice flow into the Southern Ocean from the Antarctic Ice Sheet. Shear stresses imparted by contact with islands, embayment walls, and other obstructions transmit “backstress” to grounded ice. Ice shelf collapse reduces or eliminates this backstress, increasing mass flux to the ocean and therefore rates of sea level rise. This dissertation presents studies that address three main factors that regulate ice shelf stability: surface melt, basal melt, and ice flow dynamics. The first factor, surface melt, is assessed using active microwave backscatter.
    [Show full text]
  • Did Holocene Climate Changes Drive West Antarctic Grounding Line Retreat and Re-Advance?
    https://doi.org/10.5194/tc-2020-308 Preprint. Discussion started: 19 November 2020 c Author(s) 2020. CC BY 4.0 License. Did Holocene climate changes drive West Antarctic grounding line retreat and re-advance? Sarah U. Neuhaus1, Slawek M. Tulaczyk1, Nathan D. Stansell2, Jason J. Coenen2, Reed P. Scherer2, Jill 5 A. Mikucki3, Ross D. Powell2 1Earth and Planetary Sciences, University oF CaliFornia Santa Cruz, Santa Cruz, CA, 95064, USA 2Department oF Geology and Environmental Geosciences, Northern Illinois University, DeKalb, IL, 60115, USA 3Department oF Microbiology, University oF Tennessee Knoxville, Knoxville, TN, 37996, USA 10 Correspondence to: Sarah U. Neuhaus ([email protected]) Abstract. Knowledge oF past ice sheet conFigurations is useFul For informing projections of Future ice sheet dynamics and For calibrating ice sheet models. The topology oF grounding line retreat in the Ross Sea Sector oF Antarctica has been much debated, but it has generally been assumed that the modern ice sheet is as small as it has been for more than 100,000 years 15 (Conway et al., 1999; Lee et al., 2017; Lowry et al., 2019; McKay et al., 2016; Scherer et al., 1998). Recent findings suggest that the West Antarctic Ice Sheet (WAIS) grounding line retreated beyond its current location earlier in the Holocene and subsequently re-advanced to reach its modern position (Bradley et al., 2015; Kingslake et al., 2018). Here, we further constrain the post-LGM grounding line retreat and re-advance in the Ross Sea Sector using a two-phase model of radiocarbon input and decay in subglacial sediments From six sub-ice sampling locations.
    [Show full text]
  • Report November 1996
    International Council of Scientific Unions No13 report November 1996 Contents SCAR Group of Specialists on Global Change and theAntarctic (GLOCHANT) Report of bipolar meeting of GLOCHANT / IGBP-PAGES Task Group 2 on Palaeoenvironments from Ice Cores (PICE), 1995 1 Report of GLOCHANTTask Group 3 on Ice Sheet Mass Balance and Sea-Level (ISMASS), 1995 6 Report of GLOCHANT IV meeting, 1996 16 GLOCHANT IV Appendices 27 Published by the SCIENTIFIC COMMITTEE ON ANTARCTIC RESEARCH at the Scott Polar Research Institute, Cambridge, United Kingdom INTERNATIONAL COUNCIL OF SCIENTIFIC UNIONS SCIENTIFIC COMMITfEE ON ANTARCTIC RESEARCH SCAR Report No 13, November 1996 Contents SCAR Group of Specialists on Global Change and theAntarctic (GLOCHANT) Report of bipolar meeting of GLOCHANT / IGBP-PAGES Task Group 2 on Palaeoenvironments from Ice Cores (PICE), 1995 1 Report of GLOCHANT Task Group 3 on Ice Sheet Mass Balance and Sea-Level (ISMASS), 1995 6 Report of GLOCHANT IV meeting, 1996 16 GLOCHANT IV Appendices 27 Published by the SCIENTIFIC COMMITfEE ON ANT ARCTIC RESEARCH at the Scott Polar Research Institute, Cambridge, United Kingdom SCAR Group of Specialists on Global Change and the Antarctic (GLOCHANT) Report of the 1995 bipolar meeting of the GLOCHANT I IGBP-PAGES Task Group 2 on Palaeoenvironments from Ice Cores. (PICE) Boston, Massachusetts, USA, 15-16 September; 1995 Members ofthe PICE Group present Dr. D. Raynaud (Chainnan, France), Dr. D. Peel (Secretary, U.K.}, Dr. J. White (U.S.A.}, Mr. V. Morgan (Australia), Dr. V. Lipenkov (Russia), Dr. J. Jouzel (France), Dr. H. Shoji (Japan, proxy for Prof. 0. Watanabe). Apologies: Prof. 0.
    [Show full text]
  • Variability in the Mass Flux of the Ross Sea Ice Streams, Antarctica, Over the Last Millennium
    Portland State University PDXScholar Geology Faculty Publications and Presentations Geology 1-1-2012 Variability in the Mass Flux of the Ross Sea Ice Streams, Antarctica, over the last Millennium Ginny Catania University of Texas at Austin Christina L. Hulbe Portland State University Howard Conway University of Washington - Seattle Campus Ted A. Scambos University of Colorado at Boulder C. F. Raymond University of Washington - Seattle Campus Follow this and additional works at: https://pdxscholar.library.pdx.edu/geology_fac Part of the Geology Commons Let us know how access to this document benefits ou.y Citation Details Catania. G. A., C.L. Hulbe, H.B. Conway, T.A. Scambos, C.F. Raymond, 2012, Variability in the mass flux of the Ross Sea ice streams, Antarctica, over the last millennium. Journal of Glaciology, 58 (210), 741-752. This Article is brought to you for free and open access. It has been accepted for inclusion in Geology Faculty Publications and Presentations by an authorized administrator of PDXScholar. Please contact us if we can make this document more accessible: [email protected]. Journal of Glaciology, Vol. 58, No. 210, 2012 doi: 10.3189/2012JoG11J219 741 Variability in the mass flux of the Ross ice streams, West Antarctica, over the last millennium Ginny CATANIA,1,2 Christina HULBE,3 Howard CONWAY,4 T.A. SCAMBOS,5 C.F. RAYMOND4 1Institute for Geophysics, University of Texas, Austin, TX, USA E-mail: [email protected] 2Department of Geology, University of Texas, Austin, TX, USA 3Department of Geology, Portland State University, Portland, OR, USA 4Department of Earth and Space Sciences, University of Washington, Seattle, WA, USA 5National Snow and Ice Data Center, University of Colorado, Boulder, CO, USA ABSTRACT.
    [Show full text]
  • Comparing Numerical Ice-Sheet Model Output with Radio-Echo Sounding Measurements in the Weddell Sea Sector of West Antarctica
    Annals of Glaciology Comparing numerical ice-sheet model output with radio-echo sounding measurements in the Weddell Sea sector of West Antarctica Hafeez Jeofry1,2 , Neil Ross3 and Martin J. Siegert1 Article 1Grantham Institute and Department of Earth Science and Engineering, Imperial College London, London Cite this article: Jeofry H, Ross N, Siegert MJ SW7 2AZ, UK; 2Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Terengganu (2020). Comparing numerical ice-sheet model 21300 Terengganu, Malaysia and 3School of Geography, Politics and Sociology, Newcastle University, Newcastle output with radio-echo sounding upon Tyne NE1 7RU, UK measurements in the Weddell Sea sector of West Antarctica. Annals of Glaciology 61(81), 188–197. https://doi.org/10.1017/aog.2019.39 Abstract Received: 24 July 2019 Numerical ice-sheet models are commonly matched to surface ice velocities from InSAR mea- Revised: 31 October 2019 surements by modifying basal drag, allowing the flow and form of the ice sheet to be simulated. Accepted: 31 October 2019 Geophysical measurements of the bed are rarely used to examine if this modification is realistic, First published online: 28 November 2019 however. Here, we examine radio-echo sounding (RES) data from the Weddell Sea sector of West Key words: Antarctica to investigate how the output from a well-established ice-sheet model compares with Ice-sheet modelling; ice streams; radio-echo measurements of the basal environment. We know the Weddell Sea sector contains the Institute, sounding Möller and Foundation ice streams, each with distinct basal characteristics: Institute Ice Stream lies partly over wet unconsolidated sediments, where basal drag is very low; Möller Ice Stream lies Author for correspondence: Martin J.
    [Show full text]
  • A Deep Subglacial Embayment Adjacent to the Grounding Line of Institute Ice Stream, West Antarctica
    Jeofry H, Ross N, Corr HFJ, Li J, Gogineni P, Siegert MJ. A deep subglacial embayment adjacent to the grounding line of Institute Ice Stream, West Antarctica. Exploration of Subsurface Antarctica: Uncovering Past Changes and Modern Processes. Geological Society, London, Special Publications 2017, 461 Copyright: This article is published under the terms of the CC-BY 3.0 license DOI link to article: http://doi.org/10.1144/SP461.11 Date deposited: 10/01/2018 This work is licensed under a Creative Commons Attribution 3.0 Unported License Newcastle University ePrints - eprint.ncl.ac.uk Downloaded from http://sp.lyellcollection.org/ by guest on January 10, 2018 A deep subglacial embayment adjacent to the grounding line of Institute Ice Stream, West Antarctica HAFEEZ JEOFRY1,2*, NEIL ROSS3, HUGH F. J. CORR4, JILU LI5, PRASAD GOGINENI6 & MARTIN J. SIEGERT1 1Grantham Institute and Department of Earth Science and Engineering, Imperial College London, South Kensington, London, UK 2School of Marine Science and Environment, Universiti Malaysia Terengganu, Kuala Terengganu, Terengganu, Malaysia 3School of Geography, Politics and Sociology, Newcastle University, Claremont Road, Newcastle Upon Tyne, UK 4British Antarctic Survey, Natural Environment Research Council, Cambridge, UK 5Center for the Remote Sensing of Ice Sheets, University of Kansas, Lawrence, Kansas, USA 6Electrical and Computer Engineering, University of Alabama, Tuscaloosa, Alabama, USA *Correspondence: [email protected] Abstract: The Institute Ice Stream (IIS) in West Antarctica may be increasingly vulnerable to melt- ing at the grounding line through modifications in ocean circulation. Understanding such change requires knowledge of grounding-line boundary conditions, including the topography on which it rests.
    [Show full text]