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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. ProQuest Information and Learning 300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA 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. ANTARCTIC LITHOSPHERIC ANOMALIES FROM 0RSTED SATELLITE AND NEAR-SURFACE MAGNETIC OBSERVATIONS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Hyung Rae Kim, B.Sc., M.Sc. The Ohio State University 2002 Dissertation Committee: Approved by Dr. Ralph R. B. von Frese, Adviser Dr. Hallan C. Noltimier Adviser Dr. Jeffery J. Daniels Department of Geological Sciences Dr. Beata Csatho Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 3049050 ® UMI UMI Microform 3049050 Copyright 2002 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, Ml 48106-1346 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT We investigate the utility of combining satellite and near-surface magnetic anoma­ lies for enhanced studies of the Antarctic lithosphere. We process magnetic data from the 0rsted satellite lauched in Feburary in 1999 to confirm the veracity of the Antarc­ tic lithospheric anomalies mapped by the Magsat mission over twenty years ago. Our analysis reveals that core field model estimates between degree 11 and 13 can contain significant lithospheric components. To extract these components, we use the pseudo magnetic effect of a model of Antarctic crustal thickness variations that we obtain by spectrally comparing the terrain gravity to free-air gravity anomalies. From the correlation spectrum between the pseudo magnetic and degree 11-13 satellite mag­ netic anomalies, we inversely transfrom positively correlated satellite wavenumber components for estimates of the magnetic crustal thickness effects. By combining these crustal thickness effects with the degree 13 and higher anomaly components, we obtain 0rsted and Magsat comprehensive magnetic anomaly maps of the Antarctic lithosphere at 700 km and 400 km altitudes, respectively. The comprehensive mag­ netic anomalies provide important constraints for estimating near-surface magnetic anomalies in the regional coverage gaps in the Antarctic magnetic map being pro­ duced by the Antarctic Digital Magnetic Anomaly Project (ADMAP). We develop an effective procedure for estimating near-surface anomaly values in unmapped areas from the joint inversion of satellite and available near-surface data. Relative to the ii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Magsat data, we find that the 0rsted dta offer significant advantages for this appli­ cation because of their greatly enhanced measurement accuracy. We extend the joint inversion of satellite and near-surface anomalies for modeling the crustal magnetic properties of the Maud Rise in the Southwest Indian Ocean off the coast of East Antarctica. We also find that the quantative crustal model for the Maud Rise can be extrapolated via the satellite magnetic anomalies to the conjugate Agulhas Plateau off the South African coast for new tectonic perspectives on the Cretaceous breakup of Gondwana. iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. To my parents iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENTS Foremost, I would like to thank Dr. Ralph von Frese for his sincere academic advice and guidance and financial support over the years. My thanks are also extended to the other members of the Dissertation Committee, Drs. Jeffery Daniels, Hallan Noltimier, and Beata Csatho for critical reviews of this effort. I am grateful to Drs. Michael Purucker and Patrick Taylor at NASA for their academic supports and to Dr. Jerome Dyment at CNRS and Dr. Alexander Golynsky at VNIIOkeangeologia for providing their valuable data and advice. I am also thankful to my OSU colleagues and alumni, Sangsuk Lee, Tim Leftwich, Drs. J.W. Kim, Eung-Seok Lee, Dan Roman, Laramie Potts, Changryol Kim and Giehyeon Lee for their friendship. Elements of this research were supported by grants from NASA Headquarters (Washington D.C.) and the Geodynamics Branch at the Goddard Space Flight Center (Greenbelt, MD). Additional support was provided by the Department of Geological Sciences, the Byrd Polar Research Center, the Center for Mapping, and the Ohio Supercomputer Center at the Ohio State University. And finally, I thank my parents, sisters, brothers-in-law and “only” nephew for their loving support. Also I want to thank God for giving me such a wonderful life with my wife-to-be Jaeeun. v Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. VITA March 14, 1969 Che-Ju, Korea February, 1993 B.Sc. Geology, Yonsei University, Ko­ rea. Fall, 1995 - Spring, 1997 Graduate Teaching Assistant, Purdue University, Indiana, USA. August, 1997 M.Sc. Earth and Atmospheric Sci., Purdue University, Indiana, USA. Winter, 1997 - present Graduate Research Assistant, The Ohio State University, USA. PUBLICATIONS Leftwich, T. E., R. R. B. von Frese, H. R. Kim, L. V. Potts, D. R. Roman and L. Tan, “Crustal Analysis of Venus from Magellan satellite observations at Atalanta Planitia, Beta Regio and Theta Regio,” J. Geophys. Res., 104(E4), pp. 8441-8462, 1999. Kim, H. R. and S. D. King, “A study of local time and longitudinal variability of the amplitude of the equatorial electrojet observed in POGO satellite data,” Earth, Planets, Space (formerly J. Geomag. Geoelec.), 51, pp. 373-381, 1999. von Frese, R. R. B., H. R. Kim, L. Tan, J. W. Kim, P. T. Taylor, M. E. Purucker, D. E. Alsdorf, and C. A. Raymond, “Satellite magnetic anomalies of the Antarctic crust,” Annali di Geofisica, 42, N.2, pp. 309-326, 1999. Kim, J. W., von Frese, R. R. B., and H. R. Kim, “Crustal modeling from spectrally correlated free-air and terrain gravity data - A case study of Ohio,” Geophysics, 65, pp. 1057-1069, 2000. Golynsky, A. V., M. Chiappini, D. Damaske, F. Ferraccioli, J. Ferris, C. Finn, M. Ghidella, T. Ishihara, A. Johnson, H. R. Kim, L. Kovacs, J. LaBreque, V. Masolov, VI Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Y. Nogi, M. Purucker, P. Taylor, M. Torta, “ADMAP - Magnetic anomaly map of the Antarctic, 1:10,000,000 scale map,” Morris, P. and R. von Frese., eds., BAS (Misc) 10., Cambridge, British Antarctic Survey, 2002. Kim, H. R., von Frese, R.R.B., J.W. Kim, P.T. Taylor, T. Neubert, “0rsted verifies regional magnetic anomalies of the Antarctic lithosphere,” Geophys. Res. Lett., (in­ press). FIELDS OF STUDY Major Field: Geological Sciences Studies in: Geoelectric Methods Prof. Jeffrey Daniels Remote Sensing Profs. Ken Jezek & Carolyn Merry Paleomagetism and Rheology Prof. Hal Noltimier Potential Field Geophysics Prof. Ralph von Frese Geodynamics Prof. Ian Willans Geotectonics Prof. Terry Wilson vii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS Page A b stra c t ................................................................................................................................... ii D edication ........................................................................................................................... iv Acknowledgments .................................................................................................................. v V i t a ..................................................................................................................................... vi List of Tables ..................................................................................................................... x List of Figures ................................................................................................................