In Northland, the impacts had once again included strong tidal surges at Tutukaka Harbour, similar to those which previously affected the area and other small harbours after big overseas quakes in recent years.
Mr MacDonald said the quake's effects could continue to impact Northland tides and currents around the region's east coast for another 24-36 hours.
"That's certainly been the case in previous events where we have encountered quite strong and unusual sea conditions for some time."
The massive earthquake off the coast of Chile yesterday prompted much of the Pacific to be on alert for rising waves.
New Zealand's tsunami panel of experts met this morning and issued a warning through Civil Defence for late arriving waves reflected from Pacific Islands.
Waves reaching New Zealand overnight were within the expected levels of 20cm to a metre, a spokeswoman said this morning.
Earlier today Chatham Islands mayor Alfred Preece said tidal surges there were about 50 centimetres.
"We had no significant wave heights here at all - a little bit of tidal surge between 2am and 5 this morning, but nothing significant."
Such alerts were taken seriously, Mr Preece said.
"We've been through this several times before. We've seen the results around the world if we don't get prepared. Certainly, everyone's pretty motivated here to get prepared in situations like this."
The tidal surge from Chile was audible and visible at a Northland marina when it hit about 1.30am.
"There was some really strong surges coming in, round about 10 to 12 knots," said Dive! Tutukaka owner Kate Malcolm.
The surges were still arriving, but were diluting through the ebb of their predecessors.
"There's steadily a large body of water flowing in for about 7m or 8m," Ms Malcolm said.
"Then it would follow in the opposite direction again. It was a significant surge.
"It was a very still night last night and all of a sudden you could hear the water. There was a rushing of water coming in."
Ms Malcolm expected them to continue for another 12 to 24 hours.
It was the fourth tsunami to reach the marina and was less intense than the effects of the Chile earthquake in 2010, but bigger than the Japan one of 2011 or the Samoan one in 2009.
No matter where they were from, Ms Malcolm said the water would tend to form a bottle neck around the harbour.
Divers are out today and Ms Malcolm was up until 3am monitoring conditions. This morning she and her skippers again had a look.
While the surge was visible at the shore, she said the only effects in deeper waters where the divers go would be possibly stronger currents.
Civil Defence advise:
• Stay out of the water (sea, rivers and estuaries, including boating activities).
• Stay off beaches and shore areas.
• Do not go sightseeing.
• Share this information with family, neighbours and friends.
• Monitor the media for updates.
• Follow the instructions of local civil defence authorities.
Useful websites to follow are:
• http://www.civildefence.govt.nz
• http://www.getthru.govt.nz
