Thomas M. Urban
As non-destructive geophysical methods become an increasingly popular tool for archaeological investigations for reasons of economy and site preservation, educational programs struggle to incorporate these methods into the standard archaeological curriculum. A large part of this struggle stems from the fact that geophysics is an entirely separate discipline that, like most professions, requires years of training and experience to master. What then should the typical archeologist (who cannot necessarily devote years of additional specialized study) know about geophysics? In the interest of addressing this question, the Brown University Environmental Geophysics Group in cooperation with the Artemis A.W. and Martha Sharpe Joukowsky Institute for Archaeology and the Ancient World, also at Brown, has been working for the past two years to incorporate near surface geophysics into the archaeological curriculum at the university. The developing pedagogical model presented here as a result of this cooperative effort, focuses not on turning budding archaeologists into budding geophysicists, but on training future archaeologist to collaborate more effectively with geophysicists, paving the way for better interdisciplinary research and cultural resource planning. This collaborative teaching effort began with undergraduate students, but is now filtering into the graduate program through a newly developed workshop series.

Image source: The Archaeology of College Hill
The joint endeavor began in 2006, when Professor Susan Alcock, Director of the Joukowsky Institute, invited geophysicists from Brown’s Department of Geological Sciences to conduct a non-invasive survey for an undergraduate archaeological field methods course. Dr. Robert Jacob and I conducted the survey early in the fall semester of 2006-07, using two-loop electromagnetic induction and ground penetrating radar methods. We later returned to the field site to conduct a demonstration for the students. Finally, we produced a report that was incorporated into the general site report compiled by the students and course instructors. While we enjoyed the collaboration, and the students seemed interested in our activities, we questioned how much the students actually took away from this type of interaction. Our research group decided that if invited back the following year, an effort would be made to engage students more fully in the process geophysical site assessment.

The Joukowsky Institute invited us back in the fall of 2007-08 for the next round of the field methods course. This time, a very different approach was taken. Before any surveying got underway, the students were given a lecture designed to familiarize them with some of the basic concepts and applications of archaeological geophysics. Prior lectures on the same topic given to students in the anthropology department allowed us to better gauge the appropriate content for undergraduate archaeology students that did not necessarily have an extensive background in physics or geology. The lecture was followed by a multi-method field survey at the Nightingale-Brown House, an historic property in Providence, RI, that houses Brown’s Public Humanities Program. Students participated in establishing a grid, collecting data, and taking thorough field notes. All participants rotated through these various tasks so that each got a complete hands-on experience, including operating two pieces of geophysical equipment − an electromagnetic unit and a magnetometer. At first, we had reservations about orchestrating a geophysical survey with a group of untrained undergraduates, foreseeing a number of problems that could arise in coordinating their collective activities. In spite of these doubts, however, the survey proceeded in a surprisingly smooth fashion. After processing the data that the students collected, I returned to facilitate a follow up discussion of the results. It was a success. The students actively engaged in a discussion about the data using concepts learned in the previous lecture and field exercise.
The instructor of the archaeological field methods course, Brown graduate student Katherine Marino, pointed out that the undergraduates who had participated in this introductory geophysical training probably walked away more knowledgeable about archaeological geophysics than many of the archaeology graduate students at Brown. After speaking to several other graduate students and discovering a clear interest among them in learning more about geophysics, our research team started thinking about ways to incorporate geophysics into the archaeology graduate program. We came up with the idea to offer an educational workshop series that would culminate in a multi-method field training exercise.
The concept we developed for our training program is different than most geophysics workshops in that the primary focus is not on honing a few technical skills, but on learning a whole new way of thinking about the archaeological record. Our curriculum focuses largely on building an understanding of the physical properties of archaeological targets and their geologic/morphologic environment, and how these physical properties interact with each other in light of an array of applied geophysical techniques. The main goal of our curriculum is to prepare the leaders of future archaeological projects to plan for the use of geophysics on their sites, and effectively collaborate with geophysicists in developing research strategies and disseminating findings. We define success for the program as the following:
1. Students develop an understanding of basic geophysical concepts and vocabulary that can (a.) be used to plan projects, (b.) foster interdisciplinary collaboration, (c.) make geophysical literature more accessible (d.) form a foundation for future learning
2. Students develop hands-on skills with four methods commonly used in archaeological surveying: magnetometry, two-loop electromagnetic induction, ground penetrating radar, and direct current resistivity
3. Students develop familiarity with innovative approaches and future directions of non-invasive investigations
Students completing our program will have had exposure to a variety of equipment and software. More importantly, however, participants will gain a new vocabulary and set of concepts with which to evaluate the archaeological record. With these ideas they will be armed to avoid the pitfalls of the many archaeologists who subscribe to the “black box” concept of geophysical methods, which is often to employ a favorite method without regard as to whether it is the best technique for the circumstances.
Participants in our program, as they are exposed to an entire host of methods, will be better primed for collaborative research. Many archaeologists do not think beyond ground penetrating radar when considering geophysics as an option. We intend to rid our participants of this narrow view of geophysics by exposing them to many methods and complementary combinations of methods, emphasizing multi-method strategies. We also emphasize tailoring surveys to address specific research questions and site particulars, cautioning against “blind” surveying. The tentative curriculum for the program will proceed as follows:
a.) Lecture Topics:
1. Orientation: Introduction to Archaeological Geophysics
Students receive a basic overview of the scope of archaeological geophysics and how the program will proceed.
2. Introduction to electromagnetic methods*
3. Introduction to the magnetic method*
4. Introduction to direct current resistivity*
5. Introduction to ground penetrating radar*
6. Survey Strategies
Students will be introduced to the multi-method survey strategy, and the concept of tailoring a geophysical survey to the specific needs of a site, taking into account the physical nature of expected archaeological targets and the physical nature of the hydro-geologic matrix in which those targets are situated.
7. Advanced Methods
Students will gain an overview of the more advanced procedures that are available for the commonly used methods that have already been introduced. Topics will include 3D radar imaging, 3D electrical tomography, and advanced magnetic methods.
8. Less Common and Experimental Methods
Students will be introduced to geophysical methods that are sometimes used in archaeological investigations. Topics will include gravity studies, active and passive very low frequency electromagnetic methods (VLF), seismic methods (including surface waves), and thermal imaging techniques.
*Lectures introducing the four common methods will include a qualitative overview of the laws of physics that govern a given method, how the method is used archaeologically, advantages and disadvantages of the method, and types of commercial set-ups available for the method.
b.) Lab Topics (includes field operation and data processing):
1. Electromagnetic methods
2. Magnetic methods
3. Direct current resistivity
4. Ground penetrating radar
5. Experimental methods
6. Multi-method survey exercise
This program is currently scheduled to commence next spring. A shorter trial program, however, is currently underway. This latter activity focuses on a reconnaissance survey of the John Brown House grounds, an historic property in Providence, Rhode Island. Participants will include graduate students and faculty members from the Joukowsky Institute. This project is designed to garner feedback from potential participants before the full program begins next year. The reconnaissance survey will also aid in planning the next undergraduate field methods course, tentatively scheduled to be held at the John Brown House site during in fall 2008, to include further geophysical and archaeological investigation. Participants in this trial workshop will fill out evaluations to assist in planning the full workshop series.
A geophysicist cannot be made overnight. Some guidelines for archaeological geophysics recommend that a practitioner have three or more years of experience with a given technique before being seriously considered as a consultant on an archaeological project (i.e. David, 1995). This is not because it takes three years to learn to operate the hardware or software. It is because significant experience is needed in interpreting data, and a solid grasp of the physics involved is essential if a researcher wants to work with innovative and experimental approaches to survey strategies and data analysis. An adequate quantitative background is also necessary to render the best interpretation of geophysical data, as is clear in most introductory geophysics texts (i.e. Burger, 1992, Kearey et al, 2002). The point here is that it is unreasonable to expect every archaeologist to develop these specialized skills, but not unreasonable to expect archaeologists to learn how to work with geophysicists most effectively. Archaeologists wanting to specialize in archaeological geophysics may require years of training, and are probably best served by a full course of study focusing on near surface geophysics. What we are offering is a set of critical thinking tools that is attainable by all archaeologists in a reasonable amount of time.
References
Burger, R. 1992: “Exploration Geophysics of the Shallow Subsurface”. Elglewood Cliffs, New Jersey: Prentice Hall.
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David, A. 1995: “Geophysical Survey in Archaeological Field Evaluation”. London: English Heritage Research and Professional Services Guideline No. 1.
Kearey, P., M. Brooks and I. Hill, 2002: “An Introduction to Geophysical Exploration” Third Edition. London: Blackwell Science Ltd.
Kvamme, K. and S. Ahler, 2007: “Integrated Remote Sensing and Excavation at Double Ditch State Historic Site, North Dakota”. American Antiquity. 72(3).