“I would describe the risk of a major earthquake disaster in New York of being very low — even given the inventory of old buildings,” said Mr. Hamburger, the structural engineer who specializes in seismic safety.

Hours after the earthquake on Friday it was business as usual. The New York Police Department’s chief of transit, Michael Kemper, said in a social media post that there were no reports of structural damage to the subway system, nor were there service disruptions as a result of the earthquake.

United Airlines said in a statement that “a few” flights had been diverted away from Newark Liberty International Airport, but that it was working to get those flights to the airport as soon as possible.

For Clara Dossetter, 23, and her father, David Dossetter, 67, the earthquake presented an opportunity. Visiting New York from San Francisco, they were preparing to go up the Empire State Building when the quake struck. Ms. Dossetter asked her father whether they should reconsider.

“He was like, ‘No, that’s better because no one will be there,’” she said.

Lola Fadulu, Gaya Gupta, Hurubie Meko, Michael Wilson, William J. Broad, Kenneth Chang, Emma Fitzsimmons, Sarah Maslin Nir, Erin Nolan, Mihir Zaveri, Maria Cramer, Grace Ashford, Camille Baker, Liset Cruz, Michael Paulson, Patrick McGeehan and Troy Closson contributed reporting.