location of interplate earthquakes on plate boundaries, these seismic occurrences can be differentiated by other means. Intensity Interplate earthquakes differ from intraplate earthquakes in that the intensity of intraplate earthquakes exceed those of interplate earthquakes by nearly two points. Using the Modified Mercalli Intensity scale, earthquakes are categorized descriptively on a scale from I (not felt) to XII (total destruction) based on observed effects of the seismic event. While the ground accelerations of these two types of events are similar, the resulting intensity of intraplate earthquakes is significantly greater than that of interplate earthquakes due to the greater energy release (stress drop) across intraplate faults. Stress drop Stress drop is a measure of the stress across a fault before and after an earthquake rupture. While intraplate and interplate earthquakes obey similar length proportional scaling laws, interplate earthquakes exhibit stress drop values that are systematically smaller by a factor of 6. This suggests that the boundaries between plates are significantly weaker than the plates themselves. The reason for the measurable, systemic difference in stress drop between interplate and intraplate earthquakes is not entirely understood. However, intraplate earthquake models show that stress is distributed uniformly across the fault whereas interplate earthquakes have stress concentrated in specific areas along the boundary. Furthermore, interplate earthquakes release stress immediately, as compared to intraplate earthquakes which release stress gradually. Effects Subduction erosion Basal erosion, the process of removal of materials from the underside of the upper plate by the subducting plate, occurs at numerous, but not all, convergent margins. As the process of subduction erosion is not completely understood, a model has been proposed in which basal erosion is supplemented by cyclical, interplate earthquakes. The model suggests that erosion does not occur gradually in subduction zones, but rather in brief episodes of elevated seismicity along the plate boundary. Tsunamis Earthquakes are a major factor in the creation of tsunami waves. As interplate earthquakes result in an immediate release of stress along a fault, they produce significant seismic energy and can cause seafloor uplift, generating large waves as the energy from the sudden slip along the fault is transferred to the overlying water body. However, the majority of interplate earthquakes are not intense enough to create tidal waves, with most tsunamis being caused by intraplate earthquakes or tsunami earthquakes due to their comparatively slow stress release regimes and proximity to the surface of the Earth. Major interplate