‘Proceed with caution’ as tsunami alert lifted
A national tsunami warning in force following a magnitude-8.3 earthquake off the coast of Chile has been cancelled.
Caution was still advised but the tsunami threat to New Zealand’s east coast and Chatham Islands since Thursday’s quake had largely passed, Civil Defence said yesterday.
‘‘We expect that there may be some unusual water conditions for the next 24-36 hours and advise people to be cautious and use discretion before going into the water or going out in small boats,’’ said Ministry of Civil Defence and Emergency Management director Sarah Stuart-Black.
‘‘We expect things to be back to normal within that 36-hour period.’’
On any given day New Zealand’s entire coastline could be at risk from a tsunami, she said, reminding Kiwis to be prepared in an emergency.
Overnight Thursday, sea surges at the Chatham Islands left a reef at the township of Waitangi exposed before water surged back in.
The first of the quake-generated waves reached the Chatham Islands at 11.50pm, and Civil Defence said the highest recorded there was around 50cm above normal sea level.
From North Cape down to Christchurch, including Tauranga, Gisborne, Napier, Wellington and Kaikoura, tsunami gauges recorded waves of up to 30cm above normal.
Whitebaiters and surfers ignored the warnings in Canterbury.
Chatham Islands Emergency Management said the ebb and flow of the tsunami, combined with low tide, meant the bay at Waitangi was so low reefs were visible out to boat moorings.
Mayor Alfred Preece said the reef had been exposed for quite some time before the water surged back in.
‘‘The water moving away from the shore is what seems to happen in most of these events we have experienced here,’’ he said.
No damage had been reported from anywhere around the Chathams as a result of the tsunami. We haven’t seen any significant wave height over the past night, but certainly a bit of tidal surge between 2 and 5am (local time).’’
Waitangi was on the western side of the island, while on the eastern side where he lived Preece had seen nothing significant.
‘‘Tyre tracks on the beach at midnight . . . were still on the beach this morning at 6am.’’
As a precaution, families who lived in three houses close to sea level had spent the night else- where. In Hawke’s Bay, the Napier port buoy had continuing surges since early Friday morning from 1.06m to 1.63m (a rise of 0.57 m) over 15-minute periods. Christchurch Civil Defence and Emergency Management (CDEM) manager Murray Sinclair said 30 centimetre wave surges hit Lyttelton Harbour and Sumner at 2.30am and 5am.
Civil Defence has warned people to keep away from all Canterbury beaches and river mouths until early Saturday morning fol- lowing the deadly 8.3 magnitude earthquake with more tidal activity expected.
There have been reports of whitebaiters in the water near the Waimakariri rivermouth and surfers in New Brighton.
Sinclair said said it was disappointing some people chose to ignore well-publicised warnings.
‘‘For the whitebaiters they are waist-deep in the water with their waders on.
‘‘If they are washed off their feet that’s not a good situation.
‘‘We will be getting one of the rangers to go up the Waimak river and talk to the whitebaiters and go along the beach to talk to the surfers, but it just goes to show people aren’t heeding the message to stay on out of the water today.’’
He said rangers had warned whitebaiters of the risk on Thursday, and locked a gate near the rivermouth as a precaution.
Sinclair woke several times during the night to check activity. He said the wave surges that hit Lyttelton Harbour and Sumner measured around 30cm above the normal sea level.
‘‘Which is what you could expect, there could be three, four, five surges which will peter out during the day.
University of Canterbury student Blake Williams, who surfed at New Brighton beach on Friday morning, said if there was a major risk he would expect authorities to warn people off at the beach.
He was not aware the warning remained in place.
‘‘We’ve had them before at [Mount Maunganui] and it’s never come to anything . . . obviously there’s a threat, but we weren’t so worried about it because it would only be a metre and we could sort ourselves if something happened.’’ The quake, which lasted for three minutes, caused a series of tsunami surges – some as high as 4.5 metres – to swamp towns along Chile’s coast.
It killed 10 people and forced about a million people to evacuate their homes.
Tsunami warnings were issued for Japan, Russia, California and Hawaii.