A tremble vibrated through St. Augustine in the winter of 1879, a shaking that dropped plaster from ceilings and tossed items off shelves.
Across the state in Tampa, a low rumble sounded before the shimmy was felt, reverberating through Daytona Beach and Tallahassee as a 4.4 magnitude earthquake jiggled the Sunshine State.
It was the strongest quake to hit Florida in records dating back to the 1500s and recorded in a U.S. Geological Survey report on the seismicity of the United States.
Since then, just three additional earthquakes occurred in Florida, including near Jacksonville in 1900 and two in the northwest corner of the Panhandle that both happened in March 2019. All were of magnitude 3.5 or lower, according to data from the USGS.
And despite the recent quake in Cuba and the devastating doublet that shook Venezuela June 24, it’s less likely that a calamitous quake, or even a plaster loosening shake, will occur in Florida, even though those two sites are close enough on a longitudinal scope (Miami 80 and Caracas 66) to wonder if any fault lines extend north that would illicit fear.
The short answer is ‘no.’
“Florida is on the low side as far as seismic hazards,” said Jessica Sigala, a geophysicist with the National Earthquake Information Center. “There are faults in Florida, however earthquakes don’t occur often enough for those to be named or well mapped out.”
The USGS numbers above don’t include manmade shivers, such as the 2.5 magnitude quake measured as a result of the Blue Origin rocket explosion on May 29 or vibrations from the June 8 earthquake near Cuba.
Residents across Florida noted feeling the quake in Cuba.
Where are the major fault lines in the world?
“In areas where people don’t feel earthquakes, any shaking makes people ask what is going on,” Sigala said.
Most major fault lines in the U.S. are clustered west of the Rockies, with well known names such as San Andreas in California and Wasatch line along the western base of the Wasatch Mountains in Utah.
Florida has a solid spot in the North American tectonic plate, far from the grinding edge of the Caribbean plate south of Cuba and the South American Plate south of that.
When there’s a rupture along those plates, it’s bedrock on bedrock sliding against each other.
The 2010 earthquake in Haiti that registered a 7 magnitude and killed hundreds of thousands of people occurred along the boundary separating the Caribbean plate and the North American plate and was about 710 miles southeast of Miami.
Can earthquakes happen far from a major fault line?
Although rare, earthquakes can happen even thousands of miles from a fault line.
A cluster of quakes have occurred in southern Alabama along the Florida border with the strongest measuring 4.8 in magnitude in 1997 near Flomaton, Alabama.
In 2019, two quakes hit in the northern reaches of Escambia and Santa Rosa counties. The first was a 2.9 in magnitude that happened March 7 followed by a 2.7 on March 24. More than a dozen people reported feeling the March 7 quake, according to an Associated Press story, but no damage was reported.
Christopher DuRoss, a research geologist with USGS, said there are fault lines throughout the country, including in Florida and along the east coast, but most are too small and too inactive to map.
“In Florida, there are no active faults but that doesn’t mean they aren’t there,” he said. “Even though the region is much more stable than the west coast, it can still generate earthquakes over much longer periods of time.”
Sigala likened these fault lines to a soft cookie. If you squeeze the edges, it can bend in the middle and show tiny fissures.
“But understanding their activity is challenging because we can’t map them at the surface, or see how they are expressed in the landscape,” DuRoss said.
Scientists still don’t fully understand what caused a magnitude 7 earthquake in South Carolina in 1886, he noted.
Could a tsunami triggered by an earthquake hit Florida?
While one earthquake can trigger another, as what happened in Venezuela, Florida is too far from major fault lines to have that kind of chain reaction impact.
“There is a history of tsunamis in Florida, not a lot, but it’s not 0,” said Dave Snider, a tsunami warning coordinator for the National Oceanic and Atmospheric Administration.
He said the threats to Florida come from the Caribbean, as far away as the Azores, and along the continental shelf if there is an underwater landslide.
No tsunami warning, watch or advisory was issued for Florida following the June 9 quake near Cuba. Residents who felt shaking in Florida experienced seismic waves from the earthquake itself, not tsunami activity.
The U.S. National Tsunami Warning Center said on social media that it was handling the Venezuela quakes simultaneously with a 6.9 magnitude quake near the coast of Japan on June 24.
“The earth never rests,” the post said.
Kimberly Miller is a journalist for the USA TODAY NETWORK FLORIDA. She covers weather, the environment and critters as the Embracing Florida reporter. If you have news tips, please send them to kmiller@pbpost.com. You can get all of Florida’s best content directly in your inbox each weekday by signing up for the free newsletter, Florida TODAY, at palmbeachpost.com/newsletters.
This article originally appeared on Palm Beach Post: Florida has fault lines and tremors, but could ‘the big one’ ever hit?
Reporting by Kimberly Miller, USA TODAY NETWORK – Florida / Palm Beach Post
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By Kimberly Miller, USA TODAY NETWORK – Florida | USA TODAY Network
