The forecasts, based on data from past earthquakes, do not provide predictions or warnings of impending large quakes.
A related field that uses geology to infer information regarding past earthquakes is paleoseismology.
Monitored by more than 10 seismographs, this basin has also provided focal points to at least one past earthquake in 1939.
According to the studies of past great earthquakes, a weak seismic coupling is suggested in the offshore Sanriku region.
Also, evidence for past earthquakes continues to accumulate.
They examine open trenches to look for clues about past earthquakes.
There, in the dirt, they uncovered a record of past earthquakes going back a thousand or more years.
We know from past earthquakes what is needed.
View past earthquakes, organized by year and magnitude range, in Google Earth.
Scenario earthquakes can fill this role; they can be generated for any potential hypothetical future or past historic earthquake.