והנה עודכמה קישורים (באנגלית)
קישור1 קישור2 והנה תמצות:
" Seismologists have developed a new measurement of earthquake size, called moment magnitude. Moment is a physical quantity related to the total energy released in the earthquake. It can be estimated by geologists examining the geometry of a fault in the field or by seismologists analyzing a seismogram. Because the units of moment are very large, it has been converted to the more familiar range of magnitude values for communication to the public. Moment magnitude has many advantages over other magnitude scales. First, all earthquakes can be compared on the same scale. (Richter magnitude is only precise for earthquakes of a certain size and distance from a seismometer.) Second, because it can be determined either instrumentally or from geology, it can be used to measure old earthquakes and compare them to instrumentally recorded earthquakes. Third, by estimating how large a section of fault will likely move in the future, the magnitude of that earthquake can be calculated with confidence. "
כאן הקישור למקור.
