Field geophysics, John Milsom

Archaeological ProspectionArchaeol. Prospect. 11, 129–132 (2004)

BookReviews

FIELD GEOPHYSICS

John Milsom

The third edition of this book continues in the formatof the Geological Field Guide series, being pocket-sized, but packing an expanded 230 pages. Through-out its three editions, the book has adhered to theoriginal brief to be explicitly a guide to field techni-ques. Within its 13 chapters it gives a systematiccoverage of gravity, magnetic, radiometric, electricaland EM, ground-penetrating radar, and seismic reflec-tion and refraction. In all cases the application of themethods to shallow surveys is stressed, and theapproach is strictly practical concerning the field tech-niques, with a minimum of background theory. Thisapproach is clearly explained in the foreword, andrepeated where appropriate throughout.

Much of the material is retained from the secondedition, no new chapters have been added, but there isextensive reworking of several topics. The chapters onelectrical methods are reorganized with new sectionscovering recent developments in capacitatively-coupled resistivity systems and CSAMT. An addi-tional section appears in the introductory chapterdiscussing the use of GPS for survey position fixing.The very frequent sections discussing instrumentationhave been updated throughout. The list of referenceshas been reduced, and useful URLs have been added,for equipment manufacturers, academic societies andgovernment agencies giving access to manuals, casehistories and downloadable software.

The layout of the third edition is a noticeableimprovement over the second. The text is changed tosingle column from the two-column format used pre-viously. The diagrams have been redrawn and arepresented in smaller format, but are much betterdrafted and hence clearer to the reader. In the process,in at least one case (Fig 12.6) an error has crept into thediagram, which was not present in the same diagramin the previous edition.

An essential feature of this book is the sheervolume of useful factual information and advicethat is packed into such a small format. There is arecurrent refrain of encouragement to keep detailed

written field notes to complement the data logged inthe ubiquitous digital memories of modern fieldequipment. Likewise there is continual encourage-ment for the field personnel to be thinking about thedata as it is collected, and be attempting an interpre-tation, albeit crude and approximate, as the surveyprogresses. I heartily endorse both these exhortations.The text is also peppered with personal opinions andasides. Particular butts of these are fragile laptopcomputers, fieldworkers who misuse equipment,and the manufacturers of overly complex equipment.The written style is necessarily terse, and these asidesdo relieve the intensity of the text.

The factual content of each section is generally wellselected and explained. Inevitably this selection mustomit some items, but I have found it hard to find anyomissions I would class as serious, given the remit ofthe book. The discussion of GPS does not point out theready availability of differential GPS units with real-time accuracies of the order of 1 m or better, and theability of many modern instruments to log DGPSpositions with the geophysical data. The section onseismics has a considerable discussion of the advan-tages, and safety issues with explosives. While I wouldnot argue with the veracity of any of that, the use ofexplosives in shallow work is continually declining,and this section could be condensed. I find the absenceof any reference to the plus-minus and GRM methodsin the seismic refraction section surprising. Admit-tedly these are interpretation techniques, but verywidely applied ones, and they do make demands onthe field data collection. The interpretation methoddescribed and exemplified is compatible with boththese other techniques and this relationship couldusefully be pointed out.

The level of mathematics and physics is kept to theminimum required to carry through the explanationsof the various methods. Although this should be noproblem to the trained geophysicist, I did try someisolated sections of the text, taken from the section onEM methods, on students with A-level physics. Thesestudents found the content taxing. I add this not reallyas a criticism of the text, but as an indication thatreaders do need to have a firm grasp of the relevantconcepts of classical physics.

Copyright # 2004 John Wiley & Sons, Ltd.

Overall, I like this book, regard it as a valuableaddition to my own library and recommend it to allthose involved in geophysical fieldwork. For theexperienced fieldworker it is, at the very least, aconcise revision, and for the less experienced it is amine of readily accessible information. Buy it, read it,and take it in the field with you.

Ian HillDepartment of Geology

University of Leicester, UKPublished online in Wiley InterScience

(www.interscience.wiley.com).DOI: 10.1002/arp226

REMOTE SENSING FOR SITECHARACTERIZATION

F. Kuehn, T. King, B. Hoerig and D. Peters(eds). Springer-Verlag, Berlin, 2000. £84.50(hardback). 211 pp. ISBN 3-540-63469-X.

This concise, yet comprehensive book on ‘RemoteSensing for Site Characterization’ is the first book ina series of planned publications under the general title‘Methods in Environmental Geology’ and is aimed atenvironmental managers and application scientists.

The book itself is divided into six chapters; the first ofwhich provides a brief introduction to the book, statingthe importance of using remote sensing to understandspecifically the characterization of waste disposal sites.Chapter 2 explains the basic physical fundamentals ofremote sensing, although the explanations are maybe alittle too concise with few references for the reader tofollow-up. Chapter 3 contains an overview of the differ-ent kinds of remotely-sensed data that are available forsite investigation, beginning with a brief review of thedifferences in the spatial and spectral characteristics ofcurrent satellite systems. The authors then go on to statethe most common limitations of using satellite data forwaste disposal site investigation, such as spatial andtemporal resolutions, leading the reader into the worldof airborne remote-sensing techniques. This sectionintroduces the technical aspects of a wide range ofairborne systems and provides some excellent imagesfrom aerial photography (panchromatic black and whitefilm, infrared film and colour-infrared film) and non-photographic imaging sensors, including optical-mechanical line scanners, optical-electrical scannersand imaging spectrometers.

Chapter 4 reflects on the objectives for evaluatingand investigating waste disposal sites and the impor-tance of including remote sensing in the geological andgeophysical techniques for site characterization. Thereis a good discussion on the importance in the timing ofremote sensing with respect to variations in weather

conditions and the status of surface vegetation cover,although the possibilities of multitemporal analysis forsuch investigations is rather understated. This is fol-lowed by an excellent section on the potential ofthermal imaging, clearly stating the physical andenvironmental parameters that influence the thermalbehaviour of an object and how this can aid siteinvestigations. The remainder of the chapter focuseson the characterization of waste disposal sites andtheir effects on the surrounding areas, using examplesfrom Germany, and moves on to discuss how remotesensing can be used to identify and evaluate potentialnew waste disposal sites. Although chapter 5 is rathershort, it provides a well-rounded discussion on theimportance of verifying the information extractedfrom the remotely sensed data using both virtual andin situ techniques.

Chapter 6 is by far the most substantive chapter ofthe book and outlines the advantages and limitationsof using remote sensing data for investigating wastedisposal sites in Germany and North America. Thechapter is subdivided into the main remote sensingtechniques of aerial photograph interpretation, ther-mal imaging, multispectral analysis and hyperspectralanalysis, which are individually examined withrespect to specific study sites. The characteristics andenvironmental problems associated with each studysite, covering a wide range of environmental settings,are clearly stated at the outset and this is coupled withan in-depth yet easy-to-follow discussion on the rela-tive merits and limitations of the techniques that havebeen adopted for investigation and their interpretativeoutput. The illustrations throughout this chapterprovide a good indication of the style of interpretationprovided by different remote sensing data. All in all,this chapter presents a well-rounded introduction toapplied remote a sensing for site characterization anddoes an excellent job of introducing the characteristics ofa variety of waste disposal sites and provides the readerwith methods for site investigation based on availableremote sensing data and the suitability to the environ-ment under investigation.

130 Book Reviews

Copyright # 2004 John Wiley & Sons, Ltd. Archaeol. Prospect. 11, 129–132 (2004)