It seems like a contradiction in terms - a 'small' tsunami.

But that's what came ashore in Japan Wednesday following a massive 8.1 magnitude earthquake struck several hundred kilometres offshore.

The initial wave, which hit the coast of the northern island of Hokkaido, measured less than a metre in height and was followed by three smaller ones.

It was predicted to spawn a wave two metres tall or higher, which experts feared would hit the Pacific coast of Hokkaido and main island of Honshu.

Officials had believed about two-thirds of residents in the Hokkaido town of Shibetsu living along the coast were in danger. Railway officials ordered local trains to stop at the nearest stations as a precaution.

Fortunately there were no reports of damage or injuries.

Hawaii was also under a tsunami advisory, though the Pacific Tsunami Warning Center said there wasn't any threat a destructive wave would hit the U.S. islands.

British Columbia's Provincial Emergency Program also issued a tsunami watch for the province's northern coastal islands. The watch covered the B.C. north and central coasts to the northern tip of Vancouver Island, as well as the west coast of Vancouver Island to Sombrio Point. Vancouver and Victoria weren't included.

However, it was believed those areas would also be spared any significant effects.

The quake struck at 6:15am nearly 400 kilometres east of Etorofu Island, and about 1,600 kilometres northeast of Tokyo.

A magnitude of 7.0 or larger is considered a major earthquake capable of inflicting massive damage.

On December 26, 2004, a 9.1-magnitude shaker off the coast of Indonesia caused a tsunami that killed at least 213,000 people in 11 countries.

Japan is considered particularly vulnerable to earthquakes and tsunamis because it's situated on four tectonic plates.