The Defence Force are concerned at the public distress caused by the bombing exercise north of Auckland yesterday, but hope next week’s explosions are not disruptive.
Residents from west and north Auckland reported houses shaking and a noise similar to an explosion between 4pm and 5pm.
The Defence Force said the Number 5 Squadron was on its Kaipara Bomb Range yesterday afternoon conducting trials for the P3K Orion, dropping Mk82, 500-pound bombs
The bombs usually have a maximum noise carry of 5km to 10km. Yesterday, people were reporting hearing loud bangs and shakes up to 70km from the site.
Yesterday was the first time the bombs had caused problems in nearly 20 years of annual exercises.
“We have been doing them for at least 18 years. Yesterday was the first day we had any feedback on concern over the noise,” said Air Vice Marshal Mike Yardley Chief of Air Force.
This was a product of unique weather circumstances, where a westerly breeze and layer of cloud meant the sound travelled much further, according to the Defence Force.
The training exercises were publicised in the New Zealand Herald on June 7 and 14, but the Defence Force was worried that so many people seemed unaware the exercise was taking place.
“The air force is really concerned that this has happened. To us it was once in 18 years this has happened. So, we are surprised and disappointed that this has been the case,” Yardley said.
The bombing exercises continued today, but in fresh weather no complaints were made.
The Mk82 are common all-purpose aircraft munition and contain 160 pounds of explosives, the equivalent of 440 sticks of dynamite. They were last used in combat by New Zealand troops in the 1956 Malaysian conflict.
The training was scheduled to continue next Monday, Tuesday and Wednesday, but the weather conditions would be assessed first to avoid a repetition of yesterday’s events that saw suggestions of meteors, earthquakes and volcanic eruptions as explanations of the unknown explosions.
Reports of loud bangs and houses shaking began about 4pm in the Hibiscus Coast area to Auckland's north.
Richard Hills, Labour candidate for Northcote, wrote on his Twitter page: "I heard it. Sounded like neighbours had crashed into their house."
Inspector Tony Edwards of police northern communications said police received reports of the bangs from the Herald Island - Greenhithe area about the same time. More reports came in a while later from the Ranui - Scenic Drive area in West Auckland.
A Fire Service worker came in to work later and confirmed they had heard the noises in the Red Beach area, which is on the Hibiscus Coast.
Arkles Bay resident Will Trayes said he heard the noises about 4pm.
His house shook with a "sudden, quick vibration" for two or three seconds and he heard a slight rumble similar to thunder.
Six or seven minutes later it happened again and then again six or seven minutes after that.
His sister said she thought it was a truck going past the house, he said.
''I wasn't worried, I was just wondering if there was going to be a bigger shake."
A local Facebook page was inundated with 450 comments after Kelly de Rooy posted: "Holy hell, was that an earthquake I just felt in Stanmore Bay? My entire house just shook".
Sally Louise Dodsworth wrote: ''3 big shakes here in Stillwater'' while Deborah Johnston said: ''We heard real weird noise too and the cupboards were vibrating in Red Beach.''
Kathryn Wales wrote: ''Can anyone see Rangitoto???? That's not blowing up is it???''