Rupture propagation is generally modeled using a fracture mechanics approach , likening the rupture to a propagating mixed mode shear crack . The rupture velocity is a function of the fracture energy in the volume around the crack tip , increasing with decreasing fracture energy . The velocity of rupture propagation is orders of magnitude faster than the displacement velocity across the fault . Earthquake ruptures typically propagate at velocities that are in the range 70 – 90 % of the S-wave velocity , and this is independent of earthquake size . A small subset of earthquake ruptures appear to have propagated at speeds greater than the S-wave velocity . These supershear earthquakes have all been observed during large strike-slip events . The unusually wide zone of coseismic damage caused by the 2001 Kunlun earthquake has been attributed to the effects of the sonic boom developed in such earthquakes . Some earthquake ruptures travel at unusually low velocities and are referred to as slow earthquakes . A particularly dangerous form of slow earthquake is the tsunami earthquake , observed where the relatively low felt intensities , caused by the slow propagation speed of some great earthquakes , fail to alert the population of the neighboring coast , as in the 1896 Sanriku earthquake
1896 Sanriku earthquake
1896 Sanriku earthquake
Earthquake