A moderate earthquake shook Grand Canyon National Park on Saturday, rattling glasses and sending a shudder through the canyon's south rim but causing no damage or injury, officials said.

"It was very quick," said Park Service spokesman Chuck Lundy. "It probably lasted only five or six seconds. We could hear the glasses rattling in the cupboard, and you could feel the ground rumble and shudder."The temblor was recorded at a preliminary magnitude of 4.0 on the Richter scale and occurred at 7:41 p.m. EST, said U.S. Geological Survey spokesman Don Finley in Washington, D.C.