A seismic event described as an 'experimental explosion' was detected off the coast of Florida on Tuesday, nearly two weeks after a similar occurrence. The U.S. Geological Survey (USGS) registered the event as a 3.9 magnitude earthquake east of Ponce Inlet, near Daytona Beach. The USGS listed the event with a depth of zero feet, indicating a surface-level seismic source, which is characteristic of an explosion rather than a typical tectonic earthquake.
The location of the Tuesday event is identical to where a similar seismic event was recorded on July 16. This area is known for U.S. Navy Full Ship Shock Trials (FSST), a process involving controlled underwater detonations to test the resilience of warships against battle-like explosions. These trials are part of the certification process for new or upgraded vessels, including aircraft carriers and combat ships.
Following the July 16 event, a Navy spokesperson confirmed that the future USS Ted Stevens (DDG 128) had completed the first of two planned FSSTs as part of its certification for the DDG 51 Flight III destroyer program. A comparable event was also documented off Ponce Inlet in 2021, during test explosions conducted by the Navy near the aircraft carrier USS Gerald R. Ford.