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A combination of factors played a part in why a 4.9-magnitude earthquake was so strongly felt across Hawke’s Bay yesterday, a scientist says.
One resident near the epicentre said it felt “like a truck hitting” and was the strongest shake he could recall in decades.
The 4.9 earthquake hit 20kmsouth of Hastings, near the Central Hawke’s Bay communities of Elsthorpe and Kairakau, at 5.53pm on Wednesday at a depth of 30km.
No emergency incidents were reported by police and fire services, and Central Hawke’s Bay District Council reported no damage to its infrastructure.
The last time the region suffered earthquake damage was from a 5.9 tremor that struck near Pōrangahau in 2023, sending beer bottles sliding at a pub and causing a small landslip on one road.
Almost 6000 people reported feeling the latest quake, including some from the South Island.
Earth Science NZ seismic duty officer and seismologist Florent Aden said “multiple factors” played a part in the way the earthquake was felt, including proximity to the event, depth and “site effects”, which was “basically what is under your feet”.
“In Hawke’s Bay, and in particular Hastings and Napier, there are a lot of sedimentary deposits and this tends to amplify seismic waves.”
Different earthquakes had different ways of shaking, depending on the “mechanism” or way in which each side of the fault moved.
The depth of 30km was fairly common, and so too was an aftershock being felt, as was the case yesterday, he said.
Scientists could not predict when a strong earthquake was going to hit, but typically “we can expect this aftershock sequence to quickly die down” and return to a “background” rate.
The epicentre of Wednesday night's earthquake, which was felt widely across Hawke's Bay. Photo / GeoNet
He said earthquakes occurred regularly around New Zealand, which was sometimes referred to as a background rate.
Mangakuri Beach resident George Williams lives “just over the hill” from the epicentre of the latest quake.
“It was just the two of us [in the house] here, and it just started doing a little bit of a rattle.
“We both sort of looked at each other, then it just hit like a truck hitting.