The 4.8 magnitude quake hit 18 kilometres east-northeast of Tofino at a depth of 24 kilometres.
While no damage was reported to buildings, people living near Hot Springs Cove at the north end of Clayoquot Sound have been testing the natural hot springs since Wednesday's earthquake and say the temperature has dropped significantly.
Bernard Charleson said when he put his hand over the hot springs source it was a strange feeling — the water was cool — and the sulphur smell was gone.
Charleson, who is a Hesquiaht First Nation emergency co-ordinator, believes Wednesday's earthquake is to blame.
The hot springs, which are located about 33 kilometres northwest of Tofino, have long been a popular destination for tourists, who often fly or boat in for the day.
But even before this latest quake, the temperature has been steadily falling because of other seismic shifts, he said.
"This has happened before at one of the earthquakes we had. A crack developed beneath the springs and the salt water was seeping in lowering the temperature," Charleson said.
"The temperature has been lowering itself, the hot water, it didn't rebound, it just stayed there."
Officials from Tofino will be in the area today to do more tests on the water temperature and sulphur levels.
In 2012, an earthquake near Haida Gwaii also shut off the water at some popular hot springs, but Parks Canada officials say the heat has been slowly returning to water at that site.
Google Maps: Hot Springs Cove, Vancouver Island