Mystery deepens as loud rumbling baffles experts

Wangnaui City PHOTO/FILE

Mystery surrounds the origins of a loud rumbling noise heard in the wider Wanganui region on Tuesday night.

The noise happened between 10.15pm and 10.30pm and was audible from Turakina to Waitotara.

It was loud enough to shake the ground in Ratana Pa and reportedly set off the civil defence siren there.

The topic was being discussed widely on social media, including on the Wanganui Chronicle's Facebook page.

Doreen Barns heard it in Putiki, and thought it was an earthquake. "It was extremely loud, it started with a loud bang followed by a rumble."

Piri Rurawhe said everyone had felt the shaking at Ratana Pa.

"It felt like something had hit the house," he said.

Vicky Bell from Gonville thought one of her children had fallen off their bunk bed.

"But I checked and everything was fine. It was weird."

On Bastia Hill, the noise was loud enough to make Cathy Barrett mute her television.

"I was listening for what was about to happen next - nothing happened."

A spokesman for GeoNet, which records earthquake, tsunamis and volcanic eruptions, said the organisation's recording instruments had been quiet overnight.

"Just after 10pm there was a tiny earthquake that was so small it couldn't be felt or even located accurately, and it wouldn't be enough to make a noise like that."

There were similar reports of loud noises in Auckland last year, which turned out to be caused by the Defence Force.

"Even if that was the case [with last's night noise] I would have expected our instruments to have picked it up," the spokesman said.

Delyse Diack from Stardome Observatory said it was unlikely to have been a meteor as these are detected by GeoNet. "Given they didn't pick anything up this time indicates it probably wasn't an astronomical or space-related event."