The strongest earthquake to date that was recorded is the Valdivia, Chile (May 22, 1960) earthquake (Great Chilean earthquake) with a on the moment scale magnitude of 9.5.
s waves
Chile - May 22nd 1960 - 9.5
The 7.1 magnitude Olympia earthquake in 1949 is the largest earthquake to occur in the Seattle region since records began.
about 100 or less kilometers. the Alaskan earthquake lasted about 5 minutes and had a magnitude of 9.2 in Richter scale. that was a very destructive earthquake since it is the third strongest earthquake read by the seismograph in the world and the strongest in north America.