6.1 earthquake off Cuba rattles Monroe County sheriff's headquarters

A magnitude 6.1 earthquake off Cuba briefly shook computer screens at the Monroe County Sheriff's Office headquarters on Stock Island, a reminder that even a distant offshore quake can be felt in the Keys. The tremor did not carry farther up the Lower Keys, and officials reported no tsunami threat or significant damage.

The U.S. Geological Survey said the quake struck at 18:00:27 UTC on June 8, centered about 102 to 104 kilometers west-northwest of Mantua, Cuba, at a shallow depth of 26 kilometers. USGS said the event was caused by reverse faulting and described it as an intraplate earthquake within the North America plate, roughly 400 to 450 kilometers north of the nearest active plate boundary.

USGS also said it was the largest instrumentally recorded earthquake in the Gulf of America since 1950, and one of only six magnitude 5 or larger earthquakes there since 1950. The agency estimated a low likelihood of damage, but said the event still carried a 58% chance of at least one magnitude 4 or larger aftershock within the next week.

The quake generated more than 5,000 Did You Feel It? responses, the crowd-sourced reports USGS uses to map what people experienced and where shaking reached. Reports from Florida said the quake was felt across parts of South Florida and as far away as Orlando and Jacksonville, while the National Weather Service Miami reported no tsunami threat.

In Cuba, the shaking was strong enough to rattle Havana, where reports described people evacuating buildings and moving into the streets. For Monroe County, the immediate concern was narrower: a short-lived jolt at the sheriff’s headquarters, no reported injuries, and the chance that another aftershock could still be felt in the days ahead.