The 1975 Morris earthquake occurred on July 9 , and was the state 's largest 20th-century earthquake , rated at 4.6 Mn . Eighteen years later , on June 4 , 1993 , another quake slightly shook the community . This one measured 4.1 in magnitude and ranks as the third-largest earthquake in Minnesota of the 20th century
1975 Morris earthquake
1975 Morris earthquake
Morris, Minnesota