Earthquake occurred near Merritt Island, home to Kennedy Space Center (Pictured) — Courtesy: Shutterstock — NaughtyNut
Understandably, Floridians were dubious when they learned that Wednesday night’s earthquake occurred off the east coast.
On Florida’s Space Coast, sonic booms, tremendous rumblings that can be heard almost 40 miles away when large rockets take off, and trailing flames that stripe the sky are all common sights. There’s more of this type of activity than ever before at Cape Canaveral as commercial launch traffic heats up.
Additionally, Florida’s Atlantic coast has very little seismic activity and no fault line. It’s one of the few natural calamities the state doesn’t frequently have to deal with.
Except for one occurrence, every previous incident listed by the U.S. Geological Survey as an “earthquake” off the Atlantic coast of Florida dating back to 1900 was a major detonation caused by the U.S. Navy to test the seaworthiness of its new ships against undersea mines. At its Pinecastle Bombing Range complex in the neighboring Ocala National Forest, the Navy also detonates large practice bombs, which periodically rattle doors and dishes miles away.
Please pardon skeptical Floridians who are wondering what transpired on Wednesday at 10:48 p.m. However, the USGS and other seismologists concur that it was an actual earthquake.
“The signature of the seismic waves is consistent with an earthquake,” said Oliver Boyd, a research geophysicist with the USGS. The most likely cause of the earthquake is stress on fractures in the Earth’s crust. “Just about anywhere you are on the planet, the plates are experiencing stress.”
History of earthquakes in Florida
When news broke on Thursday that a magnitude 4 earthquake had been found approximately 100 miles due east of Kennedy Space Center, professional seismologists expressed skepticism. A seismic event? Outside Florida?
Even Paul Earle, the seismologist in charge of the USGS National Earthquake Information Center, acknowledged that he was initially dubious. “In Florida?” he wondered as soon as he saw the report appear. “Are you sure?” he wrote to the analysts in a letter.
“It is highly unusual to have a seismic event in Florida or close to Florida,” said Jochen Braunmiller, a research assistant professor at the University of South Florida’s School of Geological Sciences. “So I was very surprised when I heard about it.”
Only one actual earthquake, measuring 3.2 in 1992 and located in the Bahamas, approximately 75 miles east of Florida, has been recorded in the Atlantic Ocean within 400 miles of the state’s coast, according to USGS data spanning back to 1900.
More than a dozen earthquakes have been reported 400–1,000 miles east of Florida in the Atlantic, according to USGS data.
According to USGS statistics, three earthquakes of at least 1.5 magnitude have been recorded at the northwest corner of the Panhandle along the Florida/Alabama border, and two have been recorded on the peninsula, close to Jacksonville and between Gainesville and Ocala. Off the Gulf of Mexico’s continental shelf, at least four have been noted.
According to Earle, there’s a chance that earlier years’ seismic activity below a magnitude of 2.5 was overlooked.
A coastal earthquake in Florida
The earthquake was a hot issue when Braunmiller happened to be on the Melbourne coast with a group of seismologists. According to Braunmiller, “we were all very curious about it, suspicious, and wondering what was going on.” Is there a tremor? Is there an explosion? Is that a landslide?
By Thursday afternoon, every one of the seismologists Braunmiller spoke with—including those at USF—agreed that the event was seismic. They contrasted the signal from the accident on Wednesday night with seismic data from a ship shock study conducted in 2021. He remarked, “They look very different.” “We have a good feeling that it was an earthquake.”
According to him, seismometer wave signals exhibit minute distinctions between earthquakes and explosions. “We have some comparison to some explosions the Navy did three years ago and the signal looks different.”
According to him, a great deal of energy from an underwater explosion is trapped in the ocean and moves slowly toward land. As a result, the sound wave rises and falls in the water column and arrives considerably later than the other, faster-moving seismic signal.
Associate professor of geological sciences at the University of Florida Ray Russo concurred that the observed motion was more likely to be caused by an earthquake than by an explosion.
“The waveforms look like an earthquake – the S (for shear) waves … are much larger than the P waves (for primary),” Russo told USA TODAY. “Explosions typically do not produce large S waves, although an explosion in the water could conceivably do so.”
According to the survey, Wednesday’s action occurred at a depth of six miles, give or take five miles.
“I’ve learned to never say 100 percent certain but I’m very certain this is a tectonic earthquake,” Earle stated.
Seismologists and Floridians questioned whether the Navy was using explosives offshore during the earthquake. Over 23 years, they have tested ship shock on at least nine different vessels.
“We’re not tracking any sort of large operation or shock trials or anything that would be seismic-related,” said Lt. Commander Andrew Bertucci, a Navy public affairs officer.
On Thursday, multiple tankers, cargo ships, an unnamed tugboat, and Coast Guard and Navy vessels were visible in the Atlantic according to real-time marine vessel tracking maps.
Navy ship shock trials off Florida
These are some of the previous trials off Florida’s east coast.
- USS Winston Churchill – May, June 2001
- USS Mesa Verde – August, September 2008
- USS Jackson – June, July 2016
- USS Milwaukee – September 2016
- USS Gerald R. Ford – June, August 2021
Living on Florida’s Space Coast requires getting used to strange noises.
The comments to a Facebook post from the Melbourne National Weather Service office inquiring if anyone had felt the shaking demonstrated how used to such activity the people in the area are.
“It seemed like a rocket,” other individuals said in response.
Some claimed to have rushed outside in an attempt to see a launch in the final moments. They understood that NASA’s new PACE satellite was scheduled to be launched into orbit by a SpaceX rocket. However, it didn’t occur until 1:33 a.m., almost three hours later, from the launch complex of the Cape Canaveral Space Force Station. Some believed it to be thunder, which makes sense in a place where there are more lightning strikes per square mile.
Once more on Friday morning, people living along the shore took to social media to inquire about a loud noise they had heard. They discovered that, as part of a combined Axiom and SpaceX mission, three astronauts from the International Space Station were returning to Earth in a Dragon spacecraft.
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Born and raised in South Florida, Krystal is a recent graduate from the University of Miami with professional writing experience at the collegiate and national news outlet levels. She’s a foodie who loves all things travel, the beach, & visiting new places throughout Florida.