From the wikipedia article [0]: > In the United States, the Richter scale was succeeded in the 1970s by the moment magnitude scale. The moment magnitude scale

From the wikipedia article [0]: > In the United States, the Richter scale was succeeded in the 1970s by the moment magnitude scale. The moment magnitude scale is now the scale used by the United States Geological Survey to estimate magnitudes for all modern large earthquakes which is similar but not the same. From that page's wikipedia article: > Popular press reports of earthquake magnitude usually fail to distinguish between magnitude scales, and are often reported as "Richter magnitudes" when the reported magnitude is a moment magnitude (or a surface-wave or body-wave magnitude). Because the scales are intended to report the same results within their applicable conditions, the confusion is minor. The difference mostly seems to be to do with distinguishing several quakes in a similar location. I know it's picky, but this is HN... [0] https://en.wikipedia.org/wiki/Richter_magnitude_scale https://en.wikipedia.org/wiki/Richter_magnitude_scale