2011 Virginia earthquake
The USGS found that the farthest landslide from the 2011 Virginia earthquake was from the epicenter. This is by far the greatest landslide distance recorded from any other earthquake of similar magnitude. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than from the epicenter of a magnitude 5.8 earthquake. The study suggested that the added information about East Coast earthquakes may prompt a revision of equations that predict ground shaking. "What makes this new study so unique is that it provides direct observational evidence from the largest earthquake to occur in more than 100 years in the eastern U.S. Now that we know more about the power of East Coast earthquakes, equations that predict ground shaking might need to be revised."
1959 Hebgen Lake earthquake
Although magnitude estimates for the 1959 earthquake vary (the United States Geological Survey recorded the quake at both 7.3 and 7.5, now calculated by the ISC as 7.2 ) the 1959 earthquake is comparable to the 1906 San Francisco earthquake as one of the strongest earthquakes in North America, behind the 1964 magnitude 9.2 Good Friday earthquake in Alaska. The 1959 earthquake is also the most severe earthquake in the Rocky Mountain area of the United States along with the 6.9 magnitude earthquake which struck Idaho in 1983. The landslide caused by this quake was the largest since an earthquake in Wyoming in 1925 caused a landslide amounting to of rock and debris that left 28 people dead. The death toll from the quake was also the highest since the 1925 earthquake and most recent for the Northwestern United States since an earthquake in 1927 that left seven people dead. The 1959 earthquake was also the most damaging earthquake to occur in Montana since the 1935–36 earthquakes that left four people dead. The Hebgen Lake area also experienced earthquakes again in 1964, 1974, 1977 and 1985.