The 1946 Dominican Republic earthquake occurred on August 4 at 17:51 UTC near Samaná, Dominican Republic. The mainshock measured 7.8 on the moment magnitude scale and 8.1 on the surface-wave magnitude scale. An aftershock occurred four days later on August 8 at 13:28 UTC with a moment magnitude of 7.0. A tsunami was generated by the initial earthquake and caused widespread devastation across Hispaniola. The tsunami was observed in much of the Caribbean and the northwestern Atlantic Ocean. A small tsunami was also recorded by tide gauges at San Juan in Puerto Rico, Bermuda and in the United States at Daytona Beach, Florida and Atlantic City, New Jersey.