The 7.8 earthquake that struck New Zealand last week has left behind an "enchanting" phenomenon of air bubbles rising to the surface from the sea bed below.

Kayakers have discovered the bubbling water, covering a stretch measuring about 100 metres long, off the coastline of Kaikoura, near the quake's epicentre.

It is not known how long the odd occurrence will last, but a geologist who visited the site in Whaler's Bay was transfixed by its beauty and believed it held "extreme scientific value".

Scientists will begin testing to learn more about the unusual appearance of bubbles on the water's surface. Source: Stuff

Dolphins break the surface as kayakers paddle towards the bubbles. Source: Stuff

Kaikoura, long famed for its whale watching, may now have another tourist attraction on its hands, according to scientist Matthew Hughes.

"It's quite enchanting and quite beautiful," Hughes told Stuff.co.nz , sitting in his kayak, surrounded by the bubbling waters.

"What we are seeing here is something of extreme scientific value, and also a really interesting place for tourists to come ... and see some of the impact of the earthquake."

Testing will follow, but Hughes believes it is "outgassing", possibly CO2, emanating from new fractures in rock layers deep below.

Kayakers reported the bubbles gave off a similar smell to geothermal activity in the North Island city of Rotorua. Source: Stuff

"It needs to be preserved and cared for. As long as this phenomenon persists it could be really valuable for Kaikoura," Hughes said.

The bubbles gave off a similar distinctive smell to the natural geothermal hot springs in the city of Rotorua, one of the country's most popular tourist spots, according to Stuff .

None of the kayakers, who paddled around in waters resembling the fizzing surface of a glass of Coke, noted a warmer change in temperature of the ocean.