A newsletter from Dean Katherine S. Newman
Ancient Water: The View from Space
Near Eastern archaeology and NASA. These two subjects don’t usually find their way into the same sentence, much less a single research project. But Michael Harrower, an assistant professor in the Department of Near Eastern Studies, who studies the complex societies of ancient Oman and Ethiopia, and his collaborators Ben Zaitchik (Earth and Planetary Sciences) and Martha Anderson (U.S. Department of Agriculture), are now “on board” with NASA.
They are the recipients of a major grant from the space agency to study the traces of ancient irrigation systems in the Middle East, an important clue to the origins of the earliest civilizations.
Hyper-spectral satellite imagery will be used to spot traces of ancient settlements and copper mining; radar satellites will provide visual clues to ancient irrigation systems; and measures of wetness and “evapotranspiration” will be used to examine how spatial patterns of ancient human activity are associated with availability of water.
Why would NASA be interested in the ancient world? The agency is charged with helping scientists and government officials understand water cycle changes over time and the ways human beings adapt to variations in the environment. Increasingly, they are turning to the work of archaeologists to answer questions about the role of climates and environments in past millennia of human history, as a means to better understand impacts on current and future human societies.
“Applications of geospatial technologies and satellite imagery in archaeology have been growing rapidly over the past decade,” Harrower notes. “What you can see from the air complements the more traditional approach of exploring the surface of and digging into the ground.”
Archaeological field work provides us with a lot of data on the social organization of settlements, including trade patterns evident in pottery and metals that moved around the ancient world. But to see how one settlement connected to its territorial neighbors, one has to pull the lens back and look at the traces of human activity inscribed across landscapes that are often difficult to directly observe on the ground.
From the distance of a satellite, these larger traces stand out like a forest rather than individual trees, revealing the movement of peoples and, in this instance, the disturbance and composition of sediments that indicate a settlement or irrigation system was once in place.
Ben Zaitchik points out that a growing number of archaeologists are using satellite imagery to show pictures of their sites and to find new sites. “But it’s rare to get the opportunity to work with an archaeologist like Mike Harrower, who is really interested in pushing the envelope in satellite and geospatial analysis to understand the rise and the operation of complex societies in the ancient world,” he says.
“That makes it an exciting collaboration for me from a technical perspective. I also think that Mike’s research into water histories of these civilizations is extremely relevant today; I find that his questions about the ancient world often parallel the questions that I ask about modern climate and water resources in my own research.”
Harrower has introduced his students to this intellectual fusion and trained them in the methods needed to work at the forefront of the field.
“My classes consist of archaeology majors, Near Eastern studies majors, engineers, earth and planetary science students, and people from all sorts of other disciplines who want to learn Geographic Information Systems (GIS) computer mapping technologies,” Harrower explains. “This is a rapidly burgeoning field in terms of research and employment opportunities. Students I’ve taught have gone on to work with government agencies and private contractors in archaeology and other fields. They are learning skills that are widely applicable.”
One such student, Wolfgang Alders, a junior majoring in Near Eastern studies and archaeology, seems to be following in Harrower’s footsteps. On his adviser’s advice, Alders attended an archaeological field school in Kazakhstan last summer. He returned with an idea for a project to mount a multi-spectral infrared camera on a small six-blade helicopter, which could record images that would help to differentiate archaeological remains from vegetation and refine landscape models of ancient tombs and megalithic towers in Oman.
“We want to acquire higher resolution, multi-spectral imagery of Bronze Age cairn tombs, which number in the thousands and have yet to be thoroughly mapped,” explains Alders. “These tombs, which date from 3200 to 2500 B.C., played an important role in the emergence of land and water rights during the rise of settled societies in southern Arabia. Recent research suggests they may have signified territories through reference to ancestry. To understand the distribution of these tombs is thus to better understand the emergence of social complexity and civilization in the region.”
The people who inhabited southern Arabia in ancient times had their own environmental calamities to deal with. How they managed provides us with a long view of human adaptation to climate change. We think of this as a problem of our time; our archaeologists and earth scientists remind us that these are issues that have long bedeviled human societies.
Harrower and Zaitchik exemplify the new methods that enter our repertoire when we hire faculty whose training represents the cutting edge, the interdisciplinary possibilities, and a genuine desire—shared by their senior colleagues—to place basic science and archaeological inquiry in the service of understanding contemporary problems.
We celebrate the achievements of our new colleagues—both arrived at the Krieger School in the last two years—and the connections they are building between KSAS and space scientists. The possibilities for collaboration between Krieger School faculty and their partners in the Applied Physics Lab and the Space Telescope Science Institute are extraordinary.
If we are to crack the problem of climate change, it will require all hands on deck and a generation of students trained in the use of satellite imagery and Geographic Information Systems. The ones who take classes offered by these faculty members will be right there where we need them.
Katherine S. Newman
James B. Knapp Dean