North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Graphic/Image:
Project Name: Effigy Mounds, IA (1);
Reference: Bevan, B. (1999). Some Geophysical Experiments at Effigy Mounds. Geosight, Weems, Virginia. Submitted to the Midwest Archeological Center, U.S. National Park Service, Lincoln, Nebraska.
Reversed seismic record 246. The geophones were left at the same locations as for record 245, but the impact was now at N13, on the north side of the array. The initial, small, down-going pulse that is most apparent on traces 3-6 is probably an air pulse, for its velocity is 370 m/s, similar to the velocity of sound in air, which is 340 m/s.