An earthquake with a preliminary magnitude of 6.3 struck Hawaii early Sunday morning, waking up residents and knocking out power.

The quake occurred at 7:07 a.m. near Kailua-Kona on the west coast of the Big Island of Hawaii. Researchers are still trying to ascertain how many aftershocks struck and how large they were, said Don Blakeman, a geophysicist at the National Earthquake Information Center, part of the U.S. Geological Survey.

The U.S. Geological Survey also reported several aftershocks, including one measuring a magnitude of 5.8. No damage reports were immediately available.

Blakeman said there was no risk of a Pacific-wide tsunami, but a possibility of significant wave activity in Hawaii.

The quake occurred about 155 miles to the southeast of Honolulu, the state capital, in Oahu.

Could it be that the Big Kahuna has gas?