The Great Chilean Earthquake was far and away the biggest earthquake ever. Keeping in mind that the Richter Scale runs along an exponential progression, the next largest earthquake was a 1964 tremblor in Prince William Sound, Alaska, which measured 9.2. The 2004 Indian Ocean Earthquake is the next biggest earthquake ever recorded, clocking in at 9.1 on the Richter Scale and generating a formidable tsunami which damaged much of the coastline of Southeast Asia.