National Richter Scale Day in 2025 will be on April 26. This day is celebrated annually to commemorate the birth of Charles F. Richter, an American seismologist and physicist who developed the Richter scale.

The Richter scale is a numerical measurement of the energy released by an earthquake, which helps scientists compare different seismic events. Richter developed the scale in collaboration with Beno Gutenberg, both working at the California Institute of Technology. Richter first used the scale in 1935.

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