11. Strong ground motions caused many secondary effects, including gas leaks and widespread soil liquefaction. 12. On a hard table, with a strong enough up-down ground motion , it might crack. 13. Some of the strongest ground motions ever recorded were recorded during the Northridge Earthquake. 14. This is especially suitable where the two structures may respond differently to ground motion . 15. Earthquake ground motion causes soil displacement known as free-field motion. 16. Magnitude measures a quake's total energy, as indicated by ground motion recorded on seismographs. 17. Earthquake magnitudes are measures of earthquake size calculated from ground motion recorded on seismographs. 18. This enables us to predict what ground motion might be like in a certain area. 19. Strong ground motions damage buildings, sometimes bringing about collapse. 20. IDA involves performing multiple ground motion records, each scaled to several levels of seismic intensity.
