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Reproduced with Permission of the Copyright Owner. Further Reproduction Prohibited Without Permission The 1993-1994 Surge Of Bering Glacier, Alaska Observed With Satellite Synthetic Aperture Radar Item Type Thesis Authors Roush, James Joseph Download date 04/10/2021 19:56:53 Link to Item http://hdl.handle.net/11122/8529 INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type o f computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. UMI A Bell & Howell Information Company 300 North Zed) Road, Ann Arbor MI 48106-1346 USA 313/761-4700 800/521-0600 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. THE 1993-'94 SURGE OF BERING GLACIER, ALASKA OBSERVED WITH SATELLITE SYNTHETIC APERTURE RADAR A THESIS Presented to the Faculty of the University of Alaska Fairbanks in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE By James Joseph Roush, B.A. Fairbanks, Alaska May 1996 © 1996 James Joseph Roush Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 1379805 Copyright 1996 by Roush, James Joseph All rights reserved. UMI Microform 1379805 Copyright 1996, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. THE 1993-94 SURGE OF BERING GLACIER, ALASKA OBSERVED WITH SATELLITE SYNTHETIC APERTURE RADAR By James Joseph Roush RECOMMENDED: 'W*' /)d fU/V £ / . Department Head, Geology and Geophysics APPROVED: Jean of the College of Natural Sciences IJdan of the Graduate School O' - () - 9 A Date Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Abstract Sequential synthetic aperture radar (SAR) images acquired by the First European Remote Sensing Satellite (ERS-1) were employed for observation of the 1993-'94 surge of Bering Glacier, Alaska. Evidence of accelerated motion became visible in late April 1993. Subsequently the surge front propagated down-glacier at a mean velocity of 90 m/day between 19 May and 25 August, reaching most of the 34 km perimeter of the terminus by shortly after 25 August. The calving terminus then advanced rapidly into proglacial Vitus Lake at a maximum rate, during 9 August to 18 October, of\9m/day in its central area. The propagating surge front consisted of a distributed region of undulations and bulges on the glacier surface having heights, estimated from SAR data, of 40 to 110 m and widths varying from 0.7 to 1.5 km. The measurements were made using terrain-corrected, geocoded and coregistered images. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Table of Contents A bstract ........................................................................................................................................ iii List of Figures............................................................................................................................. vi Acknowledgments....................................................................................................................viii Chapter 1 Introduction...............................................................................................................1 Chapter 2 An Overview of Glacier Surging 2.1 Introduction.................................................................................................................4 2.2 A Definition of Glacier Surging...............................................................................4 2.3 Documented Surges and the Surge Mechanism.................................................... 6 Chapter 3 Bering Glacier: History and Pre-Surge Conditions 3.1 Introduction...............................................................................................................10 3.2 Bering Glacier.......................................................................................................... 10 3.3 Historical Observations........................................................................................... 13 3.4 Current Research...................................................................................................... 14 3.5 Holocene History.....................................................................................................16 3.6 Surge History............................................................................................................19 C hapter 4 SAR Imaging 4.1 Introduction.............................................................................................................. 23 4.2 SAR Principles.........................................................................................................23 4.3 Image Errors............................................................................................................. 28 4.4 Applications ............................................................................................................. 34 Chapter 5 Image Processing 5.1 Introduction...............................................................................................................38 5.1.1 Radiometric Calibration ......................................................................... 38 5.1.2 Geocoding ................................................................................................ 38 5.1.3 Geometric Rectification ......................................................................... 39 5.2 The Terrain Correction Algorithm ........................................................................40 5.2.1 Preprocessing ...........................................................................................41 5.2.2 DEM Processing ..................................................................................... 42 5.2.3 Simulation of the SAR Image ............................................................... 44 5.2.4 SAR Correlation ...................................................................................... 45 5.2.5 Geocoding and Geometric Correction ................................................. 46 Chapter 6 Image Analysis 6.1 Introduction.............................................................................................................. 50 6.2 Measurement of Surge Propagation and Terminus Advance Rates..................50 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 6.3 Measurement of Bulge Heights and Estimation of Ice Velocity........................51 6.4 Computer Animation of Sequential Imagery........................................................ 55 Chapter 7 Results 7.1 Introduction................................................................................................................. 58 7.2 Observation in Sequential Imagery......................................................................... 58 7.3 Surge Front Propagation and Terminus Advance................................................ 70 7.4 Bulge Heights and Ice Velocity Estimates.............................................................76 7.5 Description of Computer Animation of Imagery..................................................76 7.6 Discussion of Errors...................................................................................................77 Chapter 8 Discussion 8.1 Introduction.................................................................................................................78 8.2 Comparison With Other Surges...............................................................................78 8.2.1 Size and Setting..........................................................................................79 8.2.2 Time of Surge O nset.................................................................................80 8.2.3 Surge Propagation, Ice Velocity, and Terminus Advance................. 82 8.2.4 Surge Termination and Flooding............................................................85 8.3 Surging Activity in 1995...........................................................................................87
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