Rare earthquake shakes southwest Florida

MIAMI — No hurricanes. No tornadoes. No sweeping wildfires. It was a pretty nice weekend in Florida. Except, you know, for the 6.0 magnitude earthquake.

A rare and unusually strong quake in the Gulf of Mexico rocked southwest Florida on Sunday, provoking worried calls from more than 3,000 people in the state and elsewhere in the Southeast.

No damage or injuries were reported, though many Floridians experienced dishes that rattled all by themselves, swimming pools that suddenly developed waves, and terra firma that wasn't quite as firm as they thought.

"It's always something," said Mike Stone, a spokesman for the state's Division of Emergency Management.

The quake, thought to be the strongest in the area in 30 years, struck at 10:56 a.m. and was centered 397 miles from Miami.

Experts said it was too small to generate a tsunami, though the U.S Coast Guard issued a mariner's warning, advising boaters to exercise caution in the area.

In the Miami area, the event passed virtually unnoticed, though Mary Scottoline, 82, who lives along the Venetian Causeway between Miami and Miami Beach, said she felt her bedroom tremble around 11 a.m. A former resident of San Francisco, she said she knows about these things.

"My bed shook and probably the whole room," Scottoline said. "It shook once and then it shook again."

Guy Urban, an expert at the West Coast and Alaska Tsunami Warning Center in Palmer, Alaska, said an earthquake was reported in the same part of the Gulf in February, and the causes are not clearly understood.

Quakes often occur in "subduction zones," places where two tectonic plates meet, forcing one to slide under the other. Sunday's quake occurred at a depth of about 6.2 miles.

"As far as a fault area, there are no major subduction zones in that region of the Gulf," he said. "It's a rare place historically for an earthquake."

Experts at the U.S. Geological Survey described it as an uncommon "midplate" quake, meaning that it occurred far from a place where two plates meet. In a preliminary report, they said it probably resulted from "the release of long-term tectonic stresses that ultimately originate from forces applied at the plate boundary."

In any event, it made quite an impression along Florida's Gulf Coast.

Mary Ruiz, 67, of Holmes Beach, was leaving a supermarket when she felt "an extraordinary change in motion."

She feared it was caused by an explosion, and was relieved to learn it was produced by a natural event, especially at this particular time.

Said Ruiz: "Got the 9/11 jitters, I think."

Ronnie Mason, a Coast Guard petty officer in St. Petersburg, said he saw computer monitors in the command center shake for 10 to 15 seconds.

He received numerous calls from boaters and from residents more than 80 miles inland.

The earthquake likely did not have any effect on oil operations in the Gulf of Mexico, according to Ray Connolly, a spokesman for the American Petroleum Institute, the trade association for the U.S. oil and natural-gas industry.

Only one of Florida's rare earthquakes caused significant damage. In January 1879, St. Augustine residents reported heavy shaking that knocked plaster off the walls.

Additional information from The Associated Press