The USGS recorded more than 50 aftershocks within 24 hours after the 7.7-magnitude earthquake that rocked an island off Canada's west coast on Saturday night.
The largest aftershock, measuring 6.3, was recorded at 11:54 a.m. Other aftershocks ranged between 4.0 and 5.5.
The U.S. Geological Survey said the powerful temblor hit the Queen Charlotte Islands just after 8 p.m. local time Saturday at a depth of about 3 miles (5 kilometers) and was centered 96 miles (155 kilometers) south of Masset, British Columbia. It was felt across a wide area in British Columbia, both on its Pacific islands and on the mainland.
"It looks like the damage and the risk are at a very low level," said Shirley Bond, British Columbia's minister responsible for emergency management said. "We're certainly grateful.”
The National Weather Service issued a tsunami warning for coastal areas of British Columbia, southern Alaska and Hawaii, but later canceled it for the first two and downgraded it to an advisory for Hawaii.
Lenore Lawrence, a resident of Queen Charlotte City on the Haida Gwaii, said the quake was "definitely scary," adding she wondered if "this could be the big one." She said the shaking lasted more than a minute. While several things fell off her mantle and broke, she said damage in her home was minimal.
Many on the B.C. mainland said the same.
Residents rushed out of their homes in Tofino, British Columbia on Vancouver Island when the tsunami sirens sounded, but they were allowed to return about two hours after the quake.
The Pacific Tsunami Warning Center lifted its tsunami advisory Sunday morning just before 4 a.m. local time, three hours after downgrading from a warning and less than six hours after the waves first hit the islands.
Center officials said wave heights were diminishing, though swimmers and boaters should be careful of strong or unusual currents.
The biggest waves -- about 5 feet high -- appeared to hit Maui. A popular triathlon set for the island was expected to go on as planned, with county lifeguards giving the OK for a 1 mile ocean swim.
There were no immediate reports of damage, though one person died in a fatal crash near a road that was closed because of the threat near Oahu's north shore.
Hawaii Gov. Neil Abercrombie said the state was lucky to avoid more severe surges.
"We're very, very grateful that we can go home tonight counting our blessings," Abercrombie said.
Meanwhile, the National Weather Service canceled tsunami advisories for Canada, Alaska, Washington, Oregon and California.
At first, officials said Hawaii wasn't in any danger of a tsunami after the 7.7-magnitude earthquake, which sparked tsunami warnings for southern Alaska and western Canada.
Later, officials issued a warning for Hawaii as well, saying there had been a change in sea readings. About the same time, a tsunami advisory was issued for a 450-mile stretch of U.S. coast running from north of San Francisco to central Oregon.
A small tsunami created by the quake was barely noticeable in Craig, Alaska, where the first wave or surge was recorded Saturday night.
The warning in Hawaii spurred residents to stock up on essentials at gas stations and grocery stores and sent tourists in beachside hotels to higher floors in their buildings. Bus service into Waikiki was cut off an hour before the first waves, and police in downtown Honolulu shut down a Halloween block party.
Abercrombie proclaimed an emergency, mobilizing extra safety measures.
In Alaska, the initial wave or surge was recorded at 4 inches, much smaller than forecast, said Jeremy Zidek, a spokesman for the Alaska Department of Homeland Security and Emergency Management. The first wave hit Craig about two hours after the earthquake. Surges at other Alaska communities were later recorded at 6 inches, while others were much smaller.
A dispatcher with the Del Norte County Sheriff's said no damage was reported in Crescent City, a tiny fishing community in far Northern California, or in any other locations along the county's coast.
A tsunami warning means an area is likely to be hit by a wave, while an advisory means there may be strong currents, but that widespread inundation is not expected to occur.