UPDATED 12.53am: The first tsunami waves from the big earthquake in Chile have been observed at the Chatham Islands.

The Ministry of Civil Defence says a 'blip' was seen on monitoring equipment at about 10 to midnight, roughly half an hour later than expected.

Chatham Island Council staff say describe it as an ebbing and flowing of the tide.

"Often the first wave arrivals aren't the largest, so over the next several hours its just a matter of seeing what comes through."

There have also been ocean noises associated with the tidal surge.

Tsunami waves from the earthquake in Chile are expected to begin reaching Eastern coastal areas in the next hour.

East Cape, Wellington, North Cape and Napier are all due to receive waves of between 300mm and one metre, before 1am.

People are being warned to stay away from beaches.

Waikato Civil Defence information manager Stephen Ward believes the effects will mostly occur out at sea and off the coast.

"The inundation would likely be similar to a king tide or a storm surge at worst."

 MORE: Strong Earthquake hits Chilean capital

The Ministry of Civil Defence has issued the warning following an 8.3 magnitude quake off the Chilean coast.

People in the above coastal areas should: Stay out of the water (sea, rivers and estuaries, including boating activities)

— MCDEM (@NZcivildefence) September 17, 2015

People have also been asked to stay off beaches and shore areas, and not go sightseeing.

The tsunami warning will remain in effect until a cancellation message is issued, and updates will be issued hourly.

Gisborne Harbour Master Rahul Dosshi said people need to assume the tsunami threat is still there until it is officially cancelled. 

"If someone's in the water, I would say get back to shore, put your boards alongside - secure them properly. Check your moorings and what not, and stand by for more information."

Ministry spokesman Shane Bayley said the big waves won't come until after midnight tonight.

Bayley said it takes at least 12 hours for a wave to travel across the Pacific to New Zealand.

People on the Banks Peninsula are being told to stay out of the water and off beaches following a tsunami alert from the Ministry of Civil Defence and Emergency Management.

Christchurch Civil Defence is waiting for more detailed information about the Chilean earthquake and the potential tsunami risk.

They're advising people not to go sight seeing and share information with neighbours.

 People along Northland's east coast are being warned to stay away from the coast after dark tonight.

At this stage Northland has not been specifically included in the warnings in the wake of a large earthquake off Chile.

However, Northland Civil defence spokesman, Graeme MacDonald said this may change.

He said Northlanders need to adopt a prudent approach and stay away from the water until advised otherwise.