2.2 Howell & Schultz (1975)

1) Reference

B. F. Howell, Jr. and T. R. Schultz, 1975, Attenuation of Modified Mercalli Intensity with Distance from the Epicenter, Bull. Seism. Soc. Am., Vol. 65, No. 3, 651-665.

2) Used data

- Area: North America

- Period: 1811 – 1967 years

- Magnitude: 5.2 – 8.3

- Number of events: San Andreas Province 10, Cordilleran Province 10, Eastern Province 5

3) Definition of seismic intensity

Modefied Mercalli Intensity (MMI)

4) Definition of distance

Hypocentral distance

5) Applicability written in the paper

Not specified

6) Empirical attenuation formula

Several empirical formulas are shown in the paper. Some of them include the I₀ (seismic intensity at the epicenter). Followings are the formulas using the magnitude and the distance as the parameters.