UMass Boston - Winter/Spring 2007-2008 - (Page 15)

as if you had tapped a glass bottle. It feels gritty on your fingertips or, if you’re not certain, on your tongue. (Archaeologists taste a lot of things they pick out of the dirt: Putting it on your tongue is the best way to tell pottery from bone.) In Skagafjord, the tephra from an eruption in 1104 looks like a line of white icing between the dark cakes of soil. Other lines have been dated by church records and the Greenland ice cores to 870, 950, 1000, and later. To make use of this tephrochronology, Steinberg and his colleagues devised a methodology that combined soil-coring, remotesensing, and various forms of limited digging. First they punch in a steel soil-coring tube and record the depth and quality (including tephra layers) of the soil. They examine pockets of deep soil for flecks of charcoal, peat ash, or burned bone. To places with interesting soil cores, they bring a variety of machines that can see beneath the earth, providing maps of hidden walls and hearths—though reading the scans takes skill. Adapting these remote-sensing devices to Iceland is also tricky. uNDergrouND ViSioN Steinberg spent his 2005 field season, for instance, on groundpenetrating radar (GPR). The gadget he rented looked like a babyjogger. A sealed plastic box, 18 inches square, protected the antenna, which sent pulses of microwaves into the ground. The box was fixed between bicycle wheels. A sturdy frame provided a handle and supported the data recorder. Problem was, it wouldn’t roll through knee-high grass. Worse, each bump across the lumpy ground registered as an electronic burp. So Steinberg shucked the wheels, set the antenna in a plastic tub, duct-taped on a two-by-four, and had a colleague carry the data recorder. Water off the tall grass caused the microwaves to “float,” scattering sideways instead of penetrating the ground. Steinberg discarded the tub and gave the antenna a more aerodynamic profile by duct-taping on two rounded “fenders” he had carved from a green plastic watering can. The box still bounced. Steinberg duct-taped a soccer-ball-sized rock to its top to add weight. In spite of GPR’s idiosyncrasies, Steinberg mapped a Viking Age longhouse that may have been the home of a famous female explorer. Around the year 1000, Gudrid the Far-Traveler, sister-in-law of Leif Eiriksson, twice sailed to Vinland—which archaeologists have located in Newfoundland and the Gulf of St. Lawrence. Home from his frustrating but productive field season, Steinberg searched for a new GPR machine that would incorporate the design changes he had made on the fly with rocks, two-by-fours, watering cans, and duct tape. And he found one. Undergraduate Krissy Larkin excitedly modeled it for me: The display had a harness, rather like the music stands worn by marching-band members. A cable snaked over her shoulder to an aerodynamic antenna well-weighted by its own receiver. With an aluminum handle, it was easily pulled by petite Krissy, who considered it the coolest assignment. “I always wanted to be an archaeologist,” she told me. “Before I could read, I’d go outside to search for arrowheads. I wanted to A teSt For ArChAeologY Iceland has no timber or building stone. Houses of turf, like the sod homes of prairie pioneers, were the norm until concrete was introduced in the 20th century. Once abandoned, a turf house quickly disappears, beaten by wind and rain back into the landscape. Erosion, caused by overgrazing, also plays a part. Since the Vikings came, two feet of soil has been blown from the highlands to the lowlands. This blanket of relocated soil hides a lot of history. Steinberg, who wants to map and measure all the Viking Age ruins in the valley, can’t simply walk over a farmer’s fields and look for house-shaped lumps. Yet Iceland does have one advantage: Whatever you find can be dated. Dig a hole, and the walls will be striped like a layer cake with tephra—a term for anything that spews out of a volcano and is light enough to travel. Tephra has a different color and texture from soil or sand. When you run the edge of your trowel over it, it rings out, umass boston n

Table of Contents Feed for the Digital Edition of UMass Boston - Winter/Spring 2007-2008

UMass Boston - Winter/Spring 2007-2008 Contents U News Values and Vision, Bricks and Mortar An Inauguration to Remember An Expedition to Iceland An American Original Reciprocal Dedication About Alumni Alumni Calendar A Report on Private Giving Generous Friends

UMass Boston - Winter/Spring 2007-2008

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