The unit said the location of the quake was Latitude: 15.11north, Longitude: 60.43 west at a depth of 10 kilometers.
The Miami-based National Hurricane Centre (NHC) said Kirk was now located 185 miles west south west of the French island of Martinique and that the tropical storm watches and warnings for several Caribbean islands had been discontinued. It was moving west-northwest at 14 miles per hour (22 kph).
Meanwhile, Hurricane Rosa weakened slightly off Mexico's Pacific Coast and had maximum sustained winds of 110 miles per hour (175 kph) late Friday night.
Tropical Storm Kirk weakened Friday as it pushed westward into the Caribbean on Friday with strong winds and heavy rains hammering Barbados and the Lesser Antilles, the National Hurricane Center said.
Authorities in Barbados said they helped rescue several people from a flooded home, while school was cancelled in the nearby islands of Dominica, Guadeloupe and Martinique.
Tropical-storm-force winds extend outward up to 105 miles (165 km) mainly to the east of the centre.
Acting Attorney General Edmund Hinkson stands by the government's decision to have "business as usual" today despite a Tropical Storm Warning being in effect.
Kirk is presently moving westward at 19 km/h with maximum sustained winds of 85 km/h and this motion is expected to continue for the next day or two. A tropical storm watch is in effect for St. Vincent and the Grenadines. Meteorologists warned of flash floods and mudslides.
Across eastern Puerto Rico, this storm will likely bring 2 to 4 inches of rain with isolated 6 inches for Friday and Saturday.