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.
Seismic record 245. The geophones were along line E6, from N1 to N12 (the trace numbers). The impact was made at N0. This shows the increasing delay in the arrival of the seismic wave at greater distance. The geophones detected P-waves and had a natural frequency of 40 Hz.