There were also reports of intermittent phone service immediately after the quake was felt.
Aftershocks of 5.8 and 4.8 have been recorded.
The location is reported to be 86 miles south of Masset, 126 miles south southwest of Prince Rupert and 183 miles southwest of Terrace.
A tsunami warning has been issued for portions of the north coast and central coast although any rising water that may occur is expected to be "low level."
Canada's largest earthquake since 1700 was the magnitude 8.1 event on the Queen Charlotte Fault on Aug. 22, 1949. It damaged buildings on Haida Gwaii and in Terrace, and was felt as far away as Seattle.
The boundary between the Pacific and North American plates runs underwater along the west coast of Haida Gwaii, and is B.C.'s equivalent of the San Andreas Fault in California.
Despite the earthquake weekend Hallowe'en-connected events in Terrace seem unaffected.
Around 9 pm there loud fireworks-type explosions could be heard in the horseshoe area of the city.
A performance by the Terrace Symphony Orchestra at the REM Lee Theatre was briefly stopped.
An announcer pointed out the exits and asked people to remain calm. Some people left their seats but returned soon after and the concert resumed.