This Jan. 25, 1939 file photo shows Dr. Charles Richter, director of the Carnegie Institution's Seismological Laboratory in Pasadena, Calif. A ceremony in honor of Charles Richter Day, where he was born in 1900, is planned this Friday in Butler County, about 25 miles north of Cincinnati. (AP Photo, File)

(AP)—Fans of the Ohio native credited with developing the Richter (RIK'-tur) scale for rating earthquake magnitude don't want his name and legacy forgotten.

They are determined to keep Charles Richter from fading from public memory as other magnitude measurements have been developed and references to the are used less in reports about earthquakes.

In this 1963 file photo, American seismologist Charles Francis Richter, who developed the first widely used seismic magnitude scale in 1935, studies earthquake tremors in his laboratory in Pasadena, Ca., in 1963. A ceremony in honor of Charles Richter Day, where he was born in 1900, is planned this Friday in Butler County, about 25 miles north of Cincinnati. (AP Photo, File)

A group of historians and Richter supporters has joined with local officials to establish an annual celebration of his life near the southwest Ohio site where Richter was born April 26, 1900. This year's Charles F. Richter Day ceremony on his birthday will be held Friday in Butler County, about 25 miles north of Cincinnati.

Richter, working with other scientists, is credited with developing the method for rating magnitude by measuring the produced.

Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.