A string of tsunami waves, spurred by a powerful earthquake off of Canada's west coast, have reached Hawaii, where officials are evaluating whether to issue an all-clear.

A tsunami warning was issued following a 7.7 magnitude earthquake and several aftershocks off Canada's west coast late Saturday night.

The islands remain a tsunami warning, and evacuation centers are open in dozens of locations.

Neil Abercrombie, the governor of Hawaii, has signed an emergency proclamation.

Such a proclamation hands the governor emergency powers to deal with natural and man-made disasters or emergencies.

The initial quake was centered off the Queen Charlotte Islands, near the west coast of British Columbia, according to the U.S. Geological Survey.

The Tsunami warning urges those along the immediate coastline to move to higher ground, because of the possibility large waves could be generated by the quake.

A 5.8-magnitude aftershock was felt 96 miles south of Masset, Canada, according to the USGS, followed by several smaller aftershocks.

A widespread destructive tsunami threat does not exist based on historical data, says the Pacific Tsunami Warning Center.

A tsunami warning originally issued for British Columbia and Alaska was downgraded to a tsunami advisory. Advisories for Northern California and Southern Oregon remain in place. Alaska was initially under a warning, then an advisory, but the advisory there has been canceled.

A warning was originally put in place for Hawaii as the surge from the quake ripples outward, but it has since been downgraded to an advisory.

The impact could last for hours.

"It's not just one wave, it's a succession of waves," Gerard Fryer, senior geophysicist at the Pacific Tsunami Warning Center, said.

But he noted that the tsunami will not be as significant as the devastating quake and tsunami that killed thousands in Japan in March 2011.

Local television showed images of bumper-to-bumper traffic on roads leading from the coast to inner ground. About 80,000 people live in evacuations zones in the island of Oahu, the island where Honolulu is located.

John Cummings, spokesman for Honolulu Emergency Management, said officials have opened 26 centers for evacuees.

"All islands and all shorelines will be affected when it comes in," Cummings said.

Honolulu Mayor Peter Carlisle urged residents who are already on higher ground to not clog traffic. Officials expressed concerns about emergency vehicles getting by in heavy traffic.

"A 7.7 is a big, hefty earthquake. It's not something you can ignore," Fryer said. But, he added, "this earthquake was partly under the island and mostly under shallow water." He went on to say: "I think we have to be thankful it happened where it did... if that were a heavily populated area, it would have caused significant damage. It definitely would have done significant damage if it had been under a city."

Several more waves are expected in the coming hours, at 20-minute intervals.

Watch live coverage on KITV-TV in Honolulu, Hawaii.