STAMFORD - The U.S. Geological Survey says equipment at Columbia University shows a 1.3-magnitude earthquake hit North Stamford this morning. 

Residents say the unexpected impact lasted only a few seconds and sounded like multiple trees falling nearby. 

Long Ridge fire officials say a part of the city felt the ground shake and a loud explosion was heard, but that both neighbors and officials did not suspect it had been an earthquake.

Officials say the earthquake was isolated to the northern part of the city. There have been no signs of damage in the area.