1) The document analyzes the top 20 largest earthquakes in US history by magnitude and examines patterns in their location, dates, and likelihood of causing tsunamis. 2) It finds that over half (55%) of the largest earthquakes resulted in tsunamis and most major quakes occur in the fall months. 3) While the 4 most recent major quakes ranged from magnitude 7.8-7.9, there is no direct evidence that global warming influences earthquake occurrence.

1. Top 20 Largest earthquakes

4. Monthly Analysis Most major earthquakes do occur in the Fall

5. Magnitude Analysis The magnitude of the 4 most recent major earthquakes is between 7.8 -7.9

6. Tsunami Information 55% of top 20 Earthquakes in U.S. history resulted in Tsunamis no 7.8 1812 New Madrid, Missouri no 7.8 1892 Imperial Valley, California no 7.8 1906 San Francisco, California no 7.8 1996 Andreanof Islands, Alaska yes 7.8 2003 Rat Islands, Alaska no 7.9 1857 Fort Tejon, California yes 7.9 1898 Ka'u District, Islands, Hawaii no 7.9 1899 Near Cape Yakataga, Alaska yes 7.9 1986 Andreanof Islands, Alaska yes 7.9 1987 Gulf of Alaska, Alaska no 7.9 2002 Denali Fault, Alaska no 8 1812 New Madrid, Missouri yes 8 1899 Yakutat Bay, Alaska no 8.1 1811 New Madrid, Missouri yes 8.1 1946 Unimak Islands, Alaska yes 8.2 1938 East of Shumagin Islands, Alaska yes 8.6 1957 Andreanof Islands, Alaska yes 8.7 1965 Rat Islands, Alaska yes 9 1700 Cascadia Subduction Zone (West Coast) yes 9.2 1964 Prince William Sound, Alaska Tsunamis Magnitude date Major Earthquakes

7. Tsunami vs. Magnitude scientists have found tsunami wave height is independent of earthquake magnitude and is instead linked to a rupture's vertical displacement.