 The unusually low felt intensities, along with the short period body wave magnitudes, were components of the event that narrowed its classification into that of a tsunami earthquake.Tsunami earthquakes can be influenced by both the presence of (and lack of) sediment at the subduction zone, and can be categorized as either aftershocks of megathrust earthquakes, like the M7 June 22, 1932 Cuyutlán event in Mexico, or as standalone events that occur near the upper portion of a plate interface.Northwestern University professor Emile Okal imparts that in the aftershock scenario, they can occur as a result of stress transfer from a mainshock to an accretionary wedge or a similar environment with "deficient mechanical properties", and as standalone events they can occur in the presence of irregular contacts at the plate interface in a zone that lacks sediment.