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Suggested Citation:"Front Matter." National Research Council. 2000. Seeing into the Earth: Noninvasive Characterization of the Shallow Subsurface for Environmental and Engineering Applications. Washington, DC: The National Academies Press. doi: 10.17226/5786.
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If ~ j-- e Noninvasive Characterization of the Shallow Subsurface for Environmental and Engineering Applications Board on Earth Sciences and Resources Water Science and Technology Boarcl Commission on Geosciences, Environment, and Resources National Research Council NATIONAL ACADEMY PRESS Washington, D.C.

NATIONAL ACADEMY PRESS · 2101 Constitution Avenue, NW · Washington, DC 20418 NOTICE: The project that is the subject of this report was approved by the Govern- ing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. Support for this study was through endowment funds of the National Academy of Sciences. International Standard Book Number 0-309-06359-0 Library of Congress Catalog Card Number 00-101785 Copies of this report are available from the National Academy Press; 2101 Constitu- tion Avenue, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet http://www.nap.edu. Copyright 2000 by the National Academy of Sciences. All rights reserved. Printed in the United States of America.

National Acaclemy of Sciences National Acaclemy of Engineering Institute of Meclicine National Research Council The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M. Alberts is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meet- ing national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. William A. Wulf is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the respon- sibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medi- c~ne. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Acad- emies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. William A. Wulf are chairman and vice chairman, respectively, of the National Research Council.

COMMITTEE FOR NONINVASIVE CHARACTERIZATION OF THE SHALLOW SUBSURFACE FOR ENVIRONMENTAL AND ENGINEERING APPLICATIONS PHILLIP R. ROMIG, Chair, Colorado School of Mines, Golden MIRIAM BALTUCK, National Aeronautics and Space Administration, Washington, D.C. DWAIN K. BUTLER, U.S. Army Corps of Engineers, Vicksburg, Mississippi STEPHEN H. DANBOM, Conoco, Inc., Houston, Texas WILLIAM C. GHIORSE, Cornell University, Ithaca, New York JANET S. HERMAN, University of Virginia, Charlottesville ROSEMARY KNIGHT, The University of British Columbia, Vancouver ANNE S. MELTZER, Lehigh University, Bethlehem, Pennsylvania JAMES W. MERGER, HSI GeoTrans, Inc., Sterling, Virginia JAMES K. MITCHELL, Virginia Polytechnic Institute and State University, Blacksburg F. DALE MORGAN, Massachusetts Institute of Technology, Cambridge GARY R. OLHOEFT, Colorado School of Mines, Golden KARSTEN PRUESS, Lawrence Berkeley National Laboratory, Berkeley, California BRIAN R. SPIES, Commonwealth Scientific and Industrial Research Organisation, Sydney, Australia DON W. STEEPLES, University of Kansas, Lawrence BEN K. STERNBERG, University of Arizona, Tucson KENNETH WATSON, U.S. Geological Survey, Lakewood, Colorado WILFORD R. GARDNER, University of California, Berkeley (retired); WSTB Liaison Representative SUSAN M. LANDON, Thomasson Partners Associates, Denver, Colorado; BESR Liaison Representative NRC Staff THOMAS M. USSELMAN, Study Director (from June 1996) INA B. ALTERMAN, Study Director (through May 1996) GARY D. KRAUSS, Staff Officer (through June 1997) VERNA J. BOWN, Administrative Assistant ~v

BOARD ON EARTH SCIENCES AND RESOURCES J. FREEMAN GILBERT, Chair, University of California, San Diego JOHN J. AMORUSO, Amoruso Petroleum Company, Houston, Texas PAUL B. BARTON, JR., U.S. Geological Survey (Emeritus), Reston. Virginia KENNETH I. DAUGHERTY, Geospatial Concepts, Inc., Falls Church, Virginia BARBARA L. DUTROW, Louisiana State University, Baton Rouge RICHARD S. FISKE, Smithsonian Institution, Washington, D.C. JAMES M. FUNK, Shell Continental Companies, Houston, Texas WILLIAM L. GRAF, Arizona State University, Tempe RAYMOND JEANLOZ, University of California, Berkeley SUSAN M. KIDWELL, University of Chicago, Illinois SUSAN KIEFFER, Kieffer & Woo, Inc., Palgrave, Ontario, Canada PAMELA LUTTRELL, Mobil, Dallas, Texas ALEXANDRA NAVROTSKY, University of California at Davis DIANNE R. NIELSON, Utah Department of Environmental Quality, Salt Lake City JONATHAN G. PRICE, Nevada Bureau of Mines and Geology, Reno EDWARD M. STOLPER, California Institute of Technology, Pasadena JOHN R.G. TOWNSHEND, University of Maryland, College Park MILTON H. WARD, Cyprus Amax Minerals Company, Engelwood, Colorado NRC Staff ANTHONY R. DE SOUZA, Director TAMARA L. DICKINSON, Senior Program Officer ELLEN S. KAPPEL, Senior Program Officer ANNE M. LINN, Senior Program Officer THOMAS M. USSELMAN, Senior Program Officer JENNIFER T. ESTEP, Administrative Associate VERNA J. B OWEN, Administrative Assistant JUDITH L. ESTEP, Administrative Assistant REBECCA E. SHAPACK, Project Assistant v

WATER SCIENCE AND TECHNOLOGY BOARD HENRY J. VAUX, JR., Chair, University of California, Riverside CAROL A. JOHNSTON, Vice Chair, University of Minnesota, Duluth RICHELLE ALLEN-KING, Washington State University, Pullman JOHN S. BOYER, University of Delaware, Lewes JOHN BRISCOE, The World Bank, Washington, D.C. DENISE FORT, University of New Mexico, Albuquerque EVILLE GORHAM, University of Minnesota, St. Paul CHARLES D. D. HOWARD, Charles Howard & Associates, Ltd., Victoria, British Columbia, Canada WILLIAM A. JURY, University of California, Riverside WILLIAM M. LEWIS, JR., University of Colorado, Boulder GARY S. LOGSDON, Black and Veatch, Cincinnati, Ohio RICHARD LUTHY, Carnegie-Mellon University, Pittsburgh, Pennsylvania JOHN W. MORRIS, J.W. Morris Ltd., Arlington, Virginia CHARLES R. O'MELIA, The Johns Hopkins University, Baltimore, Maryland PHILIP A. PALMER, DuPont Engineering, Wilmington, Delaware REBECCA T. PARKIN, The George Washington University Medical Center, Washington, D.C. JOAN B. ROSE, University of South Florida, St. Petersburg ERIC F. WOOD, Princeton University, Princeton, New Jersey NRC Staff STEPHEN D. PARKER, Director LAURA EHLERS, Senior Staff Officer CHRIS ELFRING, Senior Staff Officer (part time) JEFFREY JACOBS, Staff Officer WILLIAM LOGAN, Staff Officer JEANNE AQUILINO, Administrative Associate MARK GIBSON, Research Associate PATRICIA JONES, Staff Associate (part time) ANITA A. HALL, Administrative Assistant ELLEN DE GUZMAN, Senior Project Assistant ANIKE JOHNSON, Project Assistant vim

COMMISSION ON GEOSCIENCES, ENVIRONMENT, AND RESOURCES GEORGE M. HORNBERGER, Chair, University of Virginia, Charlottesville RICHARD A. CONWAY, Union Carbide Corporation (Retired), S. Charleston, West Virginia THOMAS E. GRAEDEL, Yale University, New Haven, Connecticut THOMAS J. GRAFF, Environmental Defense Fund, Oakland, California EUGENIA KALNAY, University of Maryland, College Park DEBRA S. KNOPMAN, Progressive Policy Institute, Washington, D.C. KAI N. LEE, Williams College, Williamstown, Massachusetts RICHARD A. MESERVE, Covington & Burling, Washington, D.C. J. BRAD. MOONEY, JR., J. Brad Mooney Associates, Ltd., Arlington, Virginia HUGH C. MORRIS, E1 Dorado Gold Corporation, Vancouver, British Columbia H. RONALD PULLIAM, University of Georgia, Athens MILTON RUSSELL, Joint Institute for Energy and Environment and University of Tennessee (Emeritus), Knoxville THOMAS C. SCHELLING, University of Maryland, College Park ANDREW R. SOLOW, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts VICTORIA J. TSCHINKEL, Landers and Parsons, Tallahassee, Florida E-AN ZEN, University of Maryland, College Park MARY LOU ZOBACK, U.S. Geological Survey, Menlo Park, California NRC Staff ROBERT M. HAMILTON, Executive Director GREGORY H. SYMMES, Associate Executive Director JEANETTE SPOON, Administrative and Financial Officer DAVID FEARY, Scientific Reports Officer SANDI FITZPATRICK, Administrative Associate MARQUITA SMITH, Administrative Assistant/Technology Analyst . . vat

Acknowledgments This report has been reviewed by individuals chosen for their diverse per- spectives and technical expertise, in accordance with procedures approved by the NRC' s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the authors and the NRC in making their published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The content of the review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their participation in the review of this report: Richard Benson President Technos, Inc. Miami, Florida Robert Glaccum Geosphere, Inc. Midland, Michigan Sidney Green President TerraTek, Inc. Salt Lake City, Utah Six

x ACKNOWLEDGMENTS F. Peter Haeni U.S. Geological Survey Storrs, Connecticut William J. Hinze Department of Earth and Atmospheric Sciences Purdue University West Lafayette, Indiana William G. Howard, Jr. Independent Consultant Scottsdale, Arizona Debra S. Knopman Progressive Policy Institute Washington, D.C. Walter W. Kovalick, Jr. Director, Technology Innovation Office Office of Solid Waste and Emergency Response U.S. Environmental Protection Agency Washington, D.C. Yoram Rubin Civil and Environmental Engineering University of California, Berkeley Kenneth H. Stokoe Department of Civil Engineering University of Texas, Austin While the individuals listed above have provided many constructive com- ments and suggestions, responsibility for the final content of this report rests solely with the authoring committee and the NRC.

Preface Earth science is at an unprecedented turning point at the start of the twenty- first century. The focus of the science is shifting increasingly toward the natural and built environment. Earth scientists are being called on by society to apply their knowledge and expertise to environmental and engineering problems, a tril- lion-dollar challenge for the United States and other industrialized nations. As noted in two National Research Council (NRC) reports (Solid-Earth Sci- ences and Society, 1993; Opportunities in the Hydrologic Sciences, 1991), earth scientists have considerable expertise that can be brought to bear on environ- mental problems. This near-surface environment, especially within the top 30 m,~ supports human infrastructure; yields much of the water, energy, and mineral resources; and is the repository for most municipal and industrial wastes. It is the region most susceptible to contamination and modification from human activity. Tools to characterize the near-surface environment include invasive techniques, such as drilling and trenching, and a variety of noninvasive methods employing electromagnetic or acoustical energy sources (e.g., ground penetrating radar and seismic reflection) and chemical probes (e.g., soil-gas monitors). In polluted areas, invasive techniques pose a risk to workers and the environment because they can promote the spread of contaminants. Invasive techniques provide the most direct access to the subsurface, but they are generally expensive and provide informa- tion at points in a three-dimensional subsurface. Noninvasive techniques, on the iThirty meters is only an approximate number; many applications will need characterization at a much shallower depth, whereas others will extend the depth of interest. It follows that different tech- niques have optimal depth ranges for their results, which also depend on the composition and struc- ture of the near surface x

PREFACE other hand, hold the promise for rapid and inexpensive characterization. Many can image, in three dimensions, large volumes of the subsurface, albeit at lower resolution than invasively characterized points. Advances in understanding and application of noninvasive techniques could potentially save billions of dollars through improved performance in environmental and engineering applications. Considerable progress has been made over the past decade in the area of near-surface geophysical exploration. Some of this progress has occurred as a result of adaptations of techniques developed for petroleum and mineral explora- tion, and some has resulted from advances in instrumentation, electronics, and computer processing. Many of the advances have been driven by societal needs, such as the need to assess polluted sites that threaten groundwater supplies, the preservation of buried antiquities, and the need for reliability and cost-effective- ness in geotechnical engineering. The National Research Council established the committee in August of 1995 and assigned it the specific tasks of (1) assessing current capabilities for charac- terizing the near-surface environment using noninvasive technologies; (2) identi- fying weak links in current capabilities; and (3) recommending research and de- velopment to fill these gaps. This report evaluates the state of the science, the state of the practice, and the potential for new and improved methods for non- invasive characterization of the near surface. In assessing current capabilities and recommending research and develop- ment strategies, the committee has taken a broad, long-term view that considers new techniques and technologies, including ideas for truly revolutionary ad- vances; new methods of processing data; and new theories and methods for relat- ing indirect measurements to physical, chemical, and biological properties of the subsurface. The committee based its review and evaluation on existing published literature and discussions with experts in the field. The committee restricted itself to considering applications from land even though many of the same methods could be applied and deployed from a waterborne platform or from an ice surface to look at shallow subsurface materials beneath lakes and other water bodies. The Committee on Noninvasive Characterization of the Shallow Subsurface for Environmental and Engineering Applications consisted of 18 earth and physi- cal scientists and engineers with expertise in shallow, general, and applied geo- physics, geotechnical engineering, soil physics, microbiology, geochemistry, hydrogeology, and remote sensing. The committee met six times during the study. In order to receive input from a broader audience, three of the meetings were held in concert with meetings of professional societies, including the Society of Ex- ploration Geophysicists, the Environmental and Engineering Geophysical Soci- ety, and the American Geophysical Union. This report should be useful in identifying significant new areas for research in the earth and environmental sciences to be pursued in universities and national laboratories during the next decade. The report should be of interest to policy mak

PREFAC .E . . . XIll ers in deciding where research dollars should be invested; to program managers, who fund R&D on subsurface characterization; to scientists and engineers at aca- demic institutions, national laboratories, and private industry who develop these new technologies; and to scientists and engineers within government and industry, who need this new technology for engineering and environmental applications.

Contents EXECUTIVE SUMMARY INTRODUCTION Purpose of This Report, 8 What Is Noninvasive, 9 Near-Surface Applications of Noninvasive Techniques, 10 Using the Tools and Techniques, 14 References, 16 WHY CHARACTERIZE THE SUBSURFACE? Natural Resources, 18 Groundwater Contamination and Remediation, 19 Land Mines and Unexploded Ordnance, 21 Civil Infrastructure, 24 Hazards, 25 Archaeology, 25 Basic Science, 27 References, 29 3 WHAT IS CHARACTERIZED? Properties and Processes, 31 Examples of Characterization, 33 Geological Characterization, 33 Fluids, 40 xv 6 18 31

X~7t1 Vie i Biology, 45 Buried Objects, 45 References, 49 4 METHODS OF CHARACTERIZATION Potential Field Methods, 54 Gravity Measurements, 54 Magnetic Measurements, 56 Electrical and Electromagnetic Methods, 57 Field Electrical Measurements, 59 Low Frequency Electromagnetic Field Measurements, 63 Applicability of Electrical and Electromagnetics Methods, 65 Potential Improvements of Electrical and EM Capabilities, 66 Ground Penetrating Radar, 67 Applications of Ground Penetrating Radar, 68 Opportunities for Improvement of GPR, 73 Seismic Methods, 74 Applications of Near-Surface Seismology, 78 Improving Near-Surface Seismic Methods, 84 Remote Sensing, 86 Aerial Photography, 86 Multispectral Scanners, 87 Imaging Spectroscopy, 87 Research Instruments, 88 Geochemical Methods, 89 Volatile Gas Emission, 89 Water Composition, 90 Composition of the Solid Phase, 90 Radioactive Methods, 91 Geobiological Methods, 91 References, 92 5 INTERPRETATION Review of Existing Data, 97 Data Integration, 98 Modeling, 101 Visualization, 103 Recommendation, 105 References, 106 6 NONTECHNICAL ISSUES Incentives, 107 Operational Concerns, 109 CONTENTS 52 97 107

CONTENTS Regulations, 110 Standardized Practices, 111 Health and Safety, 1 13 Institutional Barriers, 114 Information and Communication, 115 References, 119 7 REALIZING FUTURE CAPABILITIES Automation of Techniques, 122 Monitoring Temporal Variations, 124 Properties and Processes, 125 Opportunities for Innovative Measurements, 127 References, 129 . . XVII 120

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Just below our feet is an environment that supports our infrastructure, yields water, provides for agriculture, and receives our waste. Our capacity to describe, or characterize, this environment is crucial to the solution of many resource, environmental, and engineering problems. And just as medical imaging technologies have reduced the need for exploratory surgeries, a variety of technologies hold the promise for rapid, relatively inexpensive noninvasive characterization of the Earth's subsurface.

Seeing into the Earth examines why noninvasive characterization is important and how improved methods can be developed and disseminated. Looking at the issues from both the commercial and public perspectives, the volume makes recommendations for linking characterization and cost savings, closing the gap between the state of science and the state of the practice, and helping practitioners make the best use of the best methods. The book provides background on:

  • The role of noninvasive subsurface characterization in contaminant cleanup, resource management, civil engineering, and other areas.
  • The physical, chemical, biological, and geological properties that are characterized.
  • Methods of characterization and prospects for technological improvement.

Certain to be important for earth scientists and engineers alike, this book is also accessible to interested lay readers.

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