From a student in Intro GIS.
Most people have had some experience with the products of remote sensing, whether it’s looking at satellite images of landscapes or using Google Earth to pinpoint locations. Few realize the potential magnitude of RS applications. McGill geography professor Margaret Kalacska works at the cutting edge of RS, examining the possibility of using the technology to identify clandestine burials. She has conducted fieldwork in sites as far ranging as Costa Rica, but has recently begun expanding her work to a site within the province of Quebec. This research has led her to an animal cemetery at safari park situated near Hemmingford, about an hour south of Montreal, that a McGill university archaeology course is currently excavating.
What do dead elephants and zebras have to do with finding mass graves? Plenty. Very little research has been done using this particular application of RS. While geographers have used LandSat satellite imagery to examine gypsum concentrations in Iraq as a proxy for sand disturbance (and possibly the existence of graves), the region was far too dangerous for them to go in and test their hypotheses. A limited amount of work has also been undertaken in the former Yugoslavia, due to the presence of clandestine burial there. The countries where the need is greatest are frequently those in which it is most dangerous to conduct actual fieldwork. RS reduces danger to the researchers and streamlines the process of data collection – instead of highly subjective informant interviews and site selection, the use of satellite imagery enables researchers to make extremely objective assessments: either a signal is there or it is not.
Learning what kind of “signal” a grave gives off, however, is precisely what the research at Parc Safari is all about. Kalacska has undertaken similar research in Costa Rica by examining cattle burials, and used RS (specifically field spectrometry and aircraft photography) to differentiate between empty graves and graves full of carcasses due to changes in soil chemistry that resulted from decomposition. However, the burials there were at most 16 months old. The burials at Parc Safari go back at least 40 years, which will enable Kalacksa to determine whether a grave “signal” holds constant over a lengthier period, or decays with time. This information will be invaluable in developing technologies that use RS to uncover clandestine graves. It provides just one demonstration of convergences between GIS/RS and archaeology.