Internet software programs aid in search for Amazonian geoglyphs



The Web-based Google Earth software program recently has incorporated high-resolution satellite imagery that facilitates the search for landscape expressions of past civilizations that we call geoglyphs. Since 2000, about 40 such geoglyphs have been observed in overflights above recently deforested pastures of southwestern Amazonia in eastern Acre State, Brazil [Ranzi and Aguiar, 2001; Ranzi, 2003; Ranzi and Aguiar, 2004]. These geoglyphs typically are circular or rectangular, on the scale of 100 meters or more, with bordering trenches 1–3 meters deep (Figure l). Carbon-14 dating of charcoal associated with these geoglyphs indicates ages between 2500 and 1000 years B.P [Latini, 1998; Pärssinen et al., 2003].