No, that wasn't a big truck going down the road or a particularly well-fed squirrel dancing on your roof. It was an earthquake.
The United States Geological Survey indicates the quake was centered near Lake Arrowhead in southern maine, registering a 4.5 on the Richter scale.
Did you feel your house shake? It lasted only for a few seconds in my house, but it was clear that it wasn't just the house. It felt similar to the seismic activity that shook New England last year.
Where were you when you felt it?
Reader Carol H. said she felt the whole house shake. She called a friend a mile away and they felt it too.
"Thought it might be a big truck going by," she said. "No truck."
The quake happened right around 7:12 p.m.
Readers on our Facebook page reported feeling it throughout the city.
Chris Plamer said he felt it in the Meshanticut area, Carlyn Lynch McKiernan felt it in Edgewood and Greg Dore said he felt his building shake.
Not everyone felt it.
"Felt nothing," said Max Kelley.
From the USGS:
People in New England, and in its geological extension southward through Long Island, have felt small earthquakes and suffered damage from infrequent larger ones since colonial times. Moderately damaging earthquakes strike somewhere in the region every few decades, and smaller earthquakes are felt roughly twice a year. The Boston area was damaged three times within 28 years in the middle 1700's, and New York City was damaged in 1737 and 1884. The largest known New England earthquakes occurred in 1638 (magnitude 6.5) in Vermont or New Hampshire, and in 1755 (magnitude 5.8) offshore from Cape Ann northeast of Boston. The Cape Ann earthquake caused severe damage to the Boston waterfront. The most recent New England earthquake to cause moderate damage occurred in 1940 (magnitude 5.6) in central New Hampshire.
Earthquakes in the central and eastern U.S., although less frequent than in the western U.S., are typically felt over a much broader region. East of the Rockies, an earthquake can be felt over an area as much as ten times larger than a similar magnitude earthquake on the west coast. A magnitude 4.0 eastern U.S. earthquake typically can be felt at many places as far as 100 km (60 mi) from where it occurred, and it infrequently causes damage near its source. A magnitude 5.5 eastern U.S. earthquake usually can be felt as far as 500 km (300 mi) from where it occurred, and sometimes causes damage as far away as 40 km (25 mi).Faults
Earthquakes everywhere occur on faults within bedrock, usually miles deep, although some New England earthquakes occur at shallower depths. Most of New England's and Long Island's bedrock was assembled as continents collided to form a supercontinent 500-300 million years ago, raising the northern Appalachian Mountains. The rest of the bedrock formed when the supercontinent rifted apart 200 million years ago to form what are now the northeastern U.S., the Atlantic Ocean, and Europe.
At well-studied plate boundaries like the San Andreas fault system in California, often scientists can determine the name of the specific fault that is responsible for an earthquake. In contrast, east of the Rocky Mountains this is rarely the case. New England and Long Island are far from the nearest plate boundaries, which are in the center of the Atlantic Ocean and in the Caribbean Sea. New England is laced with known faults but numerous smaller or deeply buried faults remain undetected. Even the known faults are poorly located at the depths of most earthquakes. Accordingly, few, if any, earthquakes in New England can be linked to named faults. It is difficult to determine if a known fault is still active and could slip and cause an earthquake. As in most other areas east of the Rockies, the best guide to earthquake hazards in New England and Long Island is the earthquakes themselves.