If you were anywhere along Florida’s Atlantic coast on Thursday afternoon and felt something weird, you are not imagining it. The ground moved. People felt it. And the immediate assumption for a lot of those people was exactly what you would expect from residents of a state that does not typically do earthquakes: something is wrong, what was that, and should I be worried.
The answer to all three of those questions is more interesting than you might expect, and a lot less alarming.
The U.S. Geological Survey classified Thursday’s event as a strong experimental explosion in the waters off Central Florida. Not an earthquake. An explosion. It happened at approximately 3:04 PM, about 91 miles east-northeast of Ponce Inlet and 93 miles east-northeast of Daytona Beach, at or near the surface. The preliminary magnitude registered at 3.9, per Click Orlando.
Walt Disney World did not feel a thing. The parks ran normally. No disruptions, no ride closures, no guest service impacts. We checked. This story is not about something going wrong at Disney. It is about something genuinely fascinating that happened off the Florida coast and why the ground moved because of it.
What Is Actually Going On Out There
The USGS was specific in its statement. “The recorded ground motions from this event are more typical of an explosion than a naturally occurring earthquake,” the agency stated. “The Navy has conducted Full Ship Shock Trials in this region in the past.”
Full Ship Shock Trials. Let us talk about what that means because it is one of those things that sounds technical but is actually really interesting once you understand it.
When the Navy commissions a new warship, they do not just assume it can handle the physical stress of combat. They test it. The way they test it is by placing the ship in the water, positioning large underwater explosives nearby, and detonating them to simulate the shock of an actual attack. The ship shakes, its systems either hold or they do not, and engineers identify anything that needs to be fixed before the vessel enters active service. The USS Gerald R. Ford, the Navy’s most advanced aircraft carrier, went through exactly this kind of trial in the Atlantic in 2021.
Thursday’s event was the ninth classified as an experimental explosion in this region since 2016. The Navy has been doing these tests in the waters off Florida’s coast for years. The USGS tracks them. When the pattern of ground motion matches an explosion rather than a fault moving, the classification reflects that.
The reason an explosion registers as a seismic event is physics. A large detonation sends energy outward in all directions, including through the ground and seabed as seismic waves. Seismometers pick up those waves and calculate a magnitude. The wave patterns look different from natural earthquakes, which is how geologists make the distinction, but the magnitude reading is real. For comparison, a Blue Origin New Glenn rocket exploded at Cape Canaveral on May 28 and registered as a magnitude 2.5 seismic event. Big explosions move the ground. That is just what they do.
What a 3.9 Magnitude Actually Feels Like and Why Disney Was Fine
A 3.9 magnitude event is strong enough to be felt but not strong enough to cause damage. Think rattling windows, objects shifting on shelves, that disorienting feeling of the floor doing something your brain did not authorize. It is the kind of thing that makes you stop what you are doing and look around to confirm that other people felt it too.
The explosion happened 91 miles offshore. By the time the seismic waves traveled from the blast site through the ocean floor and out across Central Florida, they had lost a significant amount of their energy. Walt Disney World sits approximately 60 miles inland from the coast. Between the offshore distance and the inland distance, the resort was well outside the range where any meaningful ground motion would have been felt.
This is not something Disney had to manage. It is not something guests experienced. The 3:04 PM timeline on Thursday afternoon was a normal afternoon at the parks, nothing unusual, nothing alarming.
What This Means If You Are Going to Disney World
Short answer: absolutely nothing changes.
Florida does not sit on active fault lines. Central Florida specifically has the kind of geological stability that makes dramatic seismic events essentially impossible under normal circumstances. What happened Thursday was offshore, military-related, and has happened eight other times in this same region since 2016 without anyone at Disney World having their afternoon disrupted.
For guests with trips coming up, there is nothing to monitor, nothing to worry about, and no reason to adjust any plans. The event is classified and explained. The source is almost certainly naval testing. The precedent is well established. And the parks are open and running normally.
The only reason this story touched the Disney conversation at all is geography. Disney World is close enough to Florida’s Atlantic coast that anything seismic in the region is going to prompt the question of whether the parks were affected. In this case, they were not, and the explanation for why the ground moved is considerably more interesting than an earthquake anyway.
Were you in the Orlando area or along the Florida coast on Thursday and felt the shaking? Tell us in the comments where you were and what it felt like. And if you have a Disney World trip planned soon and you saw this story and felt a moment of concern, we hope this helped settle it. Drop any remaining questions below and we will answer them.
