1960 Valdivia earthquake
The 1960 Valdivia earthquake () or Great Chilean earthquake ("Gran terremoto de Chile") of 22 May is the most powerful earthquake ever recorded. Various studies have placed it at 9.4–9.6 on the moment magnitude scale. It occurred in the afternoon (19:11 GMT, 15:11 local time), and lasted approximately 10 minutes. The resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia and the Aleutian Islands.
1980 eruption of Mount St. Helens
An earthquake at 8:32:17 a.m. PDT (UTC−7) on Sunday, May 18, 1980, caused the entire weakened north face to slide away, creating the largest landslide ever recorded. This allowed the partly molten, high-pressure gas- and steam-rich rock in the volcano to suddenly explode northwards toward Spirit Lake in a hot mix of lava and pulverized older rock, overtaking the avalanching face.