Leland Timothy Long; Short Period Surface Wave Attenuation and Intensities in the Georgia South Carolina Piedmont Province. Seismological Research Letters ; 47 (3): 3–11. doi: https://doi.org/10.1785/gssrl.47.3.3
The decay with distance of the maximum particle velocity “A” in mm/sec for quarry explosions and earthquakes follows the equation:
where D is in kilometers and ML is the Richter magnitude as defined at 100 km. This equation is valid only in the range of 10 to 150 km for events with travel paths contained entirely within the Piedmont Province of Georgia and South Carolina. If needed, intensities from a magnitude 2.0 < ML < 5.5 event can be obtained by conversion of the particle velocities to intensity by use of the relations given by Nuttli (1973).