21. These buried faults, which cause vertical ground motion , lurk within the crust, unseen and unpredictable. 22. MAGNITUDE : 7.5 on the open-ended Richter scale, which records ground motion on a seismograph. 23. Its size was measured as 7 . 8 on the Richter scale of ground motion . 24. For transient input ( such as seismic ground motion ), the peak response is reported. 25. Modern cities built on soft sediments are especially vulnerable to damage caused by amplified ground motions . 26. A quake's magnitude is a measure of the total energy released as indicated by ground motion . 27. A quake's magnitude measures the energy released as measured by ground motion recorded on a seismograph. 28. For modern earthquakes, moment is usually estimated from ground motion recordings of earthquakes known as seismograms. 29. Nonlinear static procedures use equivalent SDOF structural models and represent seismic ground motion with response spectra. 30. The scales of earthquake magnitude, which measure earthquake size calculated from ground motion recorded on seismographs:
