Cost-Effectiveness of Geophysical Survey
Geophysical survey has often been thought of as an adjunct to traditional archaeological methods that is economically out of reach of archaeologists working with typically limited budgets. Very often, however, geophysical survey can substantially lower the cost of research as well as providing data that may not be accessible by other means. When geophysical techniques are employed as an integrated part of a research strategy, the cost of survey is typically offset by reducing (often dramatically) the need for exploratory excavation. Survey with modern instrumentation can rapidly map large areas and results can then be used to target features and areas of interest, minimizing time, labor, curation, and other costs associated with invasive testing and excavation (see Integrating Geophysical Methods).
Sample Density is a Key Issue
Geophysical survey is typically performed by sampling at regular intervals along parallel transects across the survey area. The sample density, sometimes expressed in samples per square meter, determines the effective resolution of the survey as well as the rate of coverage. Sample density is therefore a compromise between cost and the likelihood of resolving anticipated features of interest. While the per-hectare cost of survey can be reduced by lowering sample densities, a survey that cannot resolve features of interest to the investigator is worthless. Although appropriate sample densities differ between each instrument, the sample interval should be proportional to the scale and contrast of anticipated features. Appropriate transect intervals typically range from 0.25 to 1 meter, with multiple readings per linear meter along each transect. Occasionally, greater sampling intervals may be appropriate to identify general areas of activity or occupation, although it is impossible to map typical individual features. (more about sample density and resolution)
Survey instrumentation must be appropriate to the physical and archaeological contexts of the site. With few exceptions, Archaeo-Physics will employ multiple survey methods. Use of more than one geophysical technique on a site will increase both the likelihood of identifying features of interest and the richness and confidence of interpretation (more about instrumentation).
The cost of a geophysical investigation performed
by Archaeo-Physics is typically based on an estimate of time and
expenses. The amount of time needed to survey a given area will
depend on a number of factors, including choice of methods, sample
densities, and surface conditions. All of these factors can vary
greatly from one site to another, as can other expenses, such
as personnel and travel expenses. Meaningful estimates must therefore
be made on a on a site-by-site basis. Completing our pre-survey
Site Form will aid us in
assessing the feasibility and cost of geophysical methods in addressing
your research goals.
Archaeo-Physics personnel have over 40 years of combined experience in archaeological geophysics, as well as over 20 years of experience in conventional excavation and survey. We have performed surveys of hundreds of archaeological sites in North America and worldwide, encompassing a wide range of cultural and environmental contexts. This experience informs all aspects of each project, from developing an integrated research design through post-survey support. Because limited academic funding or competitive bidding are factors in all archaeological research, we will work with you to maximize the recovery of relevant data within budgetary constraints.