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The Bay of Plenty's coastal tsunami warning system is being hailed a success after testing - just hours after the biggest earthquake to strike Matata this year woke up residents across the region.
An earthquake measuring 4.7 on the Richter scale hit at 1.12am on Sunday, centred 10km northeast of the township at a depth of 2km. An aftershock measuring 4.5 on the scale followed about a minute later.
The tremors were strong enough to wake people in Tauranga, while those in Matata got a real fright.
Less than 12 hours later, the warbling sound of tsunami sirens along Mt Maunganui beach brought smiles, rather than panic, to the faces of locals.
In their first public testing, the two Meerkat sirens proved to be more successful than anticipated.
The prototype sirens, on power poles at the north end of the Mount's main beach, were tested at a quarter of their full power at midday on Sunday. Residents and emergency management staff confirmed they could hear the minute-long siren along Pilot Bay right up to the Salisbury Ave police station.
Operations manager for Tauranga and Western Bay Emergency management, Allan Pearce, said the sirens were heard further away than he had hoped for.
"We were mainly testing the penetration into the buildings in the high-rise area. The strong wind may have helped carry the sound further but as we develop it we will do further tests."
The sirens replace the previous system, after two tests of 10 sirens installed around the Western Bay were found to be a failure.
In the event of a real tsunami the sirens would sound continuously.
"If they were going full-bore then they would definitely wake you up or get your attention," Mr Pearce said. "The siren is not like any other siren you would hear and so is not going to be confused with fire or other sirens." Emergency management staff plan to test sirens on Waihi Beach, Maketu, Pukehina, Papamoa and inner harbour points to see which locations were most effective.
Matata resident Judy Watson said the quakes were getting bigger and she had heard the rumble coming before it hit.
"It sort of came, then went, then came a lot stronger," she said. "I suppose if the big one's gonna come, it's gonna come."
GNS Science spokesman Warwick Smith said the earthquakes were part of a swarm that had been occurring for two years because of New Zealand's position on the boundary of the Australian and Pacific plates.
Phil Shaw, who lives in a caravan in Matata, said he got a bit of a fright. "The caravan's shaking like hell, my wife screamed," he said.
But he said he knew of no one who was particularly worried about the earthquakes. "The camping ground is full, people here still go fishing, nobody seems to care."
