Why do the media still refer to the Richter Scale?
It’s probably more a matter of laziness than anything else, although the media actually seem to be using the term “Richter scale” less than in the past, replacing it with just plain “magnitude.” The Richter scale was never intended to be used as a worldwide scale; it was designed to compare Southern California quakes up to about magnitude 6, at which point the particular seismometer model used as a reference standard reached its maximum deflection and became saturated. All magnitude scales (Richter, surface, moment) are logarithmic, and small tremors can be assigned negative values in any of them.
