The Six Most Significant East Coast Earthquakes

Aug. 24, 2011— -- intro: Tuesday's earthquake, felt by residents all along the East Coast, may not have resulted in destruction, but seismologists say the shaker was unlike anything they'd expected in the area and could have been far more dangerous.

Seismic activity on the East Coast is relatively rare compared to the West Coast (Alaska, California and Hawaii are the three states with the most earthquakes in the U.S.). Even so, there have been several earthquakes of historical importance on the Eastern seaboard -- some of which caused millions of dollars in damage. Here's a list of the top six:

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title: The Plattsburgh Earthquake

text: On April 20, 2002, an earthquake that reverberated across the Northeastern U.S. and southern Canada struck Plattsburgh, N.Y., damaging roads.

Measuring 5.1 in magnitude, the temblor centered in the mountainous Adirondack region, an area with frequent seismic activity. The New York Times reported a 200-foot portion of Route 9N collapsed 12 miles south of Plattsburgh, and County Road 39 was also damaged. People in a nearby town lost power.

Leonardo Seeber, a senior research scientist at Columbia University's Lamont-Doherty Earth Observatory in New York told ABCNews.com it was the biggest earthquake to strike the area since 1983.

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category: The East Coast's Major Earthquakes

title: The Massena Earthquake

text: The 1944 Massena, N.Y., earthquake, centered midway between Massena and Cornwall in Ontario, Canada, occurred Sept. 5, causing an estimated $2 million in property damage. In Massena, 90 percent of the chimneys were either destroyed or damaged. In addition, home foundations, plumbing systems and masonry were also battered.

Hogansburg and several other nearby towns also felt the quake's effects. In addition, several water wells went dry, and cracks could be seen in the ground at Hogansburg. To this day, according to the U.S. Geological Survey, it is the biggest earthquake New York state had ever seen, measuring 5.8 in magnitude.

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category: The East Coast's Major Earthquakes

title: The Reading Earthquakes

text: In 1994 two, earthquakes struck Reading, Pa., the biggest of which registered 4.6, which was, at the time, the strongest to hit Pennsylvania. The quake was felt throughout southeastern Pennsylvania and as far as Toronto.

According to a report published in the Journal of Geophysical Research, it caused about $2 million of damage -- the most destruction in the Eastern United States since the 1944 earthquake that struck New York.

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category: The East Coast's Major Earthquakes

title: The Pymatuning Earthquake

text: The largest earthquake ever recorded in Pennsylvania occurred in 1998, striking the Pymatuning Lake region in the northwestern part of the state on Sept. 25, according to the Pennsylvania Department of Conservation and Natural Resources.

A U.S. Geological Survey study published the following year recounted the troubling problems produced by the 5.2 quake: about 120 wells went dry in the three months after the temblor, while others started to flow, eventually causing pond levels to rise. There were also several complaints about water quality, with residents reporting black water or water that smelled like sulfur.

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category: The East Coast's Major Earthquakes

title: The Cape Ann Earthquake

text: The 1755 earthquake in Cape Ann, Mass., occurred Nov. 18 and could be felt from Halifax, Nova Scotia, south to the Chesapeake Bay in Maryland. It caused the most damage in the region around Cape Ann and Boston, where nearly 1,600 chimneys were knocked down and several brick walls collapsed. In some areas near Boston, cracks opened in the earth. Even people aboard a ship east of Cape Ann felt the shock so strongly that they thought the ship had run aground.

The Cape Ann quake is estimated to have had a magnitude of 6.0, according to the Northeast States Emergency Consortium.

During the same year, on Nov. 1, an earthquake nearly destroyed Lisbon, Portugal, and 60,000 people died. Leonardo Seeber, a senior research scientist at Columbia University's Lamont-Doherty Earth Observatory in New York, believes there may have been a connection between this earthquake and the Cape Ann earthquake.

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category: The East Coast's Major Earthquakes

title: The South Carolina Earthquake

text: According to data from the U.S. Geological Survey, the highest magnitude earthquake recorded on the U.S. East Coast occurred in Charleston, S.C., in 1886, registering 7.3 with aftershocks scattering as far inland as Columbia. The quake "caused substantial damage," said Seeber.

"It was dramatic in that railroad tracks were bent, and there was a lot of liquefaction," he said, referring to the process by which sand turns into a semi-liquid.

The earthquake, considered the most damaging in the Southeast United States, killed 60 people and damaged nearly every structure. Dramatic photos show home walls having crumbled to the ground.

Additional damage was reported several miles from Charleston, from central Alabama to central Ohio and the earthquake was felt as far away as Boston.