FLAGLER BEACH, Fla. – The U.S. Geological Survey recorded a magnitude 3.9 experimental explosion Tuesday morning off Florida’s Atlantic coast, noting the seismic event was consistent with an explosion rather than a naturally occurring earthquake.
According to the U.S. Geological Survey (USGS), the event occurred at 12:12:54 p.m. EDT (17:12:54 UTC) on Tuesday, July 28, 2026, approximately 171 kilometers (106 miles) east-northeast of Flagler Beach at a reported depth of 0.0 kilometers.
The USGS classified the event as an “Experimental Explosion” after reviewing the seismic data. On its event page, the agency stated that the recorded ground motions “are more typical of an explosion than a naturally occurring earthquake.”
The agency also noted that the U.S. Navy has previously conducted Full Ship Shock Trials in the region. Those trials are designed to evaluate the survivability of naval vessels by detonating explosive charges in the water near ships under controlled conditions.
As of Tuesday, the USGS had received only a handful of public “Did You Feel It?” reports, and there were no immediate reports of damage or injuries associated with the event.
Officials have not announced any public safety concerns related to the offshore blast. The event occurred well offshore in the Atlantic Ocean and was reviewed by the USGS before being published.
Residents along Florida’s east coast who believe they felt the event can submit observations through the USGS “Did You Feel It?” reporting system, which helps scientists better understand how seismic events are experienced by the public.
