Thane Grauel

tgrauel@lohud.com

GARRISON – People living in the Hudson Highlands were startled Saturday morning by an earthquake that didn't shake the ground, but was accompanied by a loud boom.

The "micro earthquake" struck at 10:46 a.m., 3.1 miles beneath the Appalachian Trail in a heavily wooded area of Garrison.

The Lamont-Doherty Cooperative Seismographic Network reported on its website that it was a magnitude-2.5 earthquake. The location, according to Lamont-Doherty, was 13 miles southeast of Newburgh, and 23 miles north-northwest of White Plains. The coordinates, 41.36 north and 73.934 west, place it a few miles north of Peekskill.

Most people in the Lower Hudson Valley didn't hear or feel a thing. But those near the epicenter were startled into the streets.

Kathy Percacciolo lives on Route 9D in Garrison, not far from where the quake struck. Her daughter, Tara Percacciolo, lives next door.

"I thought somebody hit the house," she said. "I went outside to look and my daughter came running out and said, 'What was that?' I said maybe it was an earthquake."

She said she felt one once before, around 1984.

The Appalachian Trail crosses South Mountain Pass in Garrison, where Christine Schaetzl and her husband Ted A'Zary live.

"We heard this loud boom and the windows shook," Schaetzl said. "My husband went outside to see if someone's gas grill blew up."

She said she'd felt earthquakes before, but had never heard one.

"It was kind of scary," she said. "It echoed through the valley."

Thomas Pitt, who lives on Lake Street in Highland Falls, heard and felt the quake as well, even though he's on the other side of the Hudson River.

"I was sitting in the basement and there's this big rumble, a loud boom," he said. "Everyone was coming out of their houses, looking for smoke," he said.

People wondered if a gas main had exploded.

It was hours later that word came it was an earthquake.

"My wife said everyone was trying to figure it out on Facebook," Pitt said.

The U.S. Geological Survey listed the event at a category 5 earthquake, which typically causes light shaking and no damage. Its scale starts at 1, the weakest, and ends with 10-plus, the most devastating.

Leonardo Seeber, a seismologist and geologist at Lamont-Doherty, said the earthquake was in a wooded area of the Hudson Highlands, and not along any known fault lines, including the nearby Ramapo Fault.

Scientists keep a close eye on the Ramapo Fault because of the Indian Point nuclear power plant.

Seeber said more earthquakes might be coming soon.

"They tend to come in bursts," he said.