April 26, 2025, marks the 125th birthday of Cincinnati native Charles Richter, the inventor of the Richter Scale. The seismologist, aka Earth scientist, invented the critical measurement tool to help better understand the magnitude of earthquakes.
Who is Charles Richter? How does the Richter Scale work? Did Richter grow up in Ohio? Here’s what to know.
What is the Richter scale?
Invented by Richter and his colleague Beno Gutenberg, the Richter Scale is a magnitude scale used to measure the intensity of earthquakes.
The scale helps assign a numerical value to quantify the amount of seismic energy (the energy of waves that travel through the Earth) released by an earthquake.
It is measured on a scale from under one to 10. Here is what the scale looks like:
< 2.0: Micro (Micro earthquakes, not felt)
2.0-2.9: Minor (Generally not felt, but recorded)
3.0-3.9: Minor (Often felt, but rarely causes damage)
4.0-4.9: Light (Noticeable shaking of indoor items, rattling noises. Significant damage is unlikely)
5.0-5.9: Moderate (Can cause significant damage to poorly constructed buildings over small regions. At most slight damage to well-designed buildings)
6.0-6.9: Strong (Can be destructive in areas up to about 100 miles across in populated areas)
7.0-7.9: Major (Can cause severe damage over larger areas)
8.0-8.9: Great (Can cause severe damage in areas several hundred miles across)
9.0-9.9: Great (Devastating in areas several thousand miles across)
10.0+: Epic (Earthquakes over 10 have never been recorded)
Ohio was hit with an earthquake on April 22 that registered as a 3.1 magnitude on the Richter Scale. Like the Heimlich maneuver or the Cleveland Browns, the invention is probably more famous than the inventor.
Who is Charles Richter?
Charles F. Richter was born April 26, 1900, near Cincinnati in Overpeck, a section of St. Clair Township in Butler County. He later moved to California with his family and studied earthquakes at the California Institute of Technology, earning a Ph.D. in theoretical physics while working at the Seismology Institute.
In 1935, he published a paper that described his earthquake magnitude scale, widely known as the Richter Scale, making Richter a household name.
The annual Richter Day is celebrated on his birthday, April 26, across the country and at his historical marker in Trenton, Ohio.
When did Charles Richter die?
Richter was 85 when he died in Pasadena, California, on Sept. 30, 1985.
This article originally appeared on Cincinnati Enquirer: What is the Richter Scale? Meet the Ohio native who invented it