Charles Francis Richter What emerged, of course, was that the magnitude scale presupposed that all earthquakes were alike except for a constant scaling factor. And this proved to be closer to the truth than we expected. – Charles Francis Richter
Charles Francis Richter We would have been happy if we could have assigned just three categories, large, medium, and small; the point is, we wanted to avoid personal judgments. It actually turned out to be quite a finely tuned scale. – Charles Francis Richter
Charles Francis Richter This is very similar to astronomy where different magnitudes are assigned to the brightness of an astronomical object, depending on the range of wavelengths being measured. – Charles Francis Richter
Charles Francis Richter There is another common misapprehension that the magnitude scale is itself some kind of instrument or apparatus. Visitors will frequently ask to ‘see the scale.’ – Charles Francis Richter
Charles Francis Richter In every area of the world where there is earthquake risk, there are still many buildings of this type; it is very frustrating to try to get rid of them. – Charles Francis Richter
Charles Francis Richter If the assumptions used in calculating energy are changed, then this seriously affects the final result, even though the same body of data might be used. – Charles Francis Richter
Charles Francis Richter I usually point out that most loss of life and property has been due to the collapse of antiquated and unsafe structures, mostly of brick and other masonry. – Charles Francis Richter
Charles Francis Richter I repeatedly have to correct this belief. In a sense, magnitude involves steps of 10 because every increase of one magnitude represents a tenfold amplification of the ground motion. But there is no ‘scale of 10’ in the sense of an upper limit. – Charles Francis Richter
Charles Francis Richter From here, it becomes an engineering problem; the engineer considers the ground motion that will occur and evaluates the requirements of the proposed structure in the light of the local foundation conditions. – Charles Francis Richter
Charles Francis Richter For example, some stars put out large amounts of energy in the infrared part of the spectrum, so that this can produce a different relative magnitude rating than using light energy from the middle of the spectrum. – Charles Francis Richter
Charles Francis Richter Emphasis was usually put on the horizontal acceleration factor, for the simple reason that ordinary structures have a built-in safety factor for the vertical component; that is, gravity. – Charles Francis Richter
Charles Francis Richter By moving them vertically, a representative mean curve could be formed, and individual events were then characterized by individual logarithmic differences from the standard curve. – Charles Francis Richter
