 Complete the following phrase:  The local magnitude scale was developed on the basis of shallow  deep, moderate-sized earthquakes at a distance of approximately , conditions where the surface waves are predomit. At greater depths, distances, or magnitudes the surface waves are greatly reduced, and the local magnitude scale underestimates the magnitude, a problem called saturation. Additional scales were developed  a surface-wave magnitude scale  by Beno Gutenberg in 1945, a body-wave magnitude scale  by Gutenberg and Richter in 1956, and a number of variants  to overcome the deficiencies of the scale, but all are subject to saturation. A particular problem was that the scale which in the 1970s was the preferred magnitude scale saturates around and therefore underestimates the energy release of great earthquakes such as the 1960 Chilean and 