 One of the initial characterizations of tsunami earthquakes came from seismologist Hiroo Kanamori in the early 1970s, and additional clarity materialized following the 1992 Nicaragua earthquake and tsunami, which was evaluated to have a surface wave magnitude of 7.0 when analyzing short period seismic signals.When longer period signals of around 250 seconds were investigated, the shock was reevaluated to have a moment magnitude of 7.6, with a hypothesis that the slow nature of the slip of the event may have concealed its substantial extent.Sediment was thought to have contributed to a slower rupture, due to a lubrication effect at the plate interface, with the result being an earthquake signature that had abundant long period seismic signals, which could be an important factor in the tsunami-generation process.