Many said they experienced the jolt as a short violent burst of energy .
"Started with sharp jolt straight up through floor in Normandale," posted Dean Russell
Within 15 minutes a second larger quake struck Seddon.
The shallow 4.8 Seddon quake sent people screaming in fear as it violently jolted the top of the South Island at 9.42pm.
It was felt widely across the New Zealand with those closest to the epicentre running to check their children were safe.
Donna Keefe posted on Facebook she screamed when the quake struck.
"Blenheim rocked AGAIN. I screamed like nobody's business and scared myself. Checked on the kids upstairs and my last baby (11) was awake because she heard me screaming. So I brought her in my room and got my dog right by us. The rest of my whanau slept through it. I wish these plates would just settle down."
Others complained the quakes were taking a toll on their health with the fortnight of constant tremors robbing them of sleep.
The quake, which was at a depth of 11 km and 15 km east of the town, was also felt widely across central New Zealand and as far afield as Whangarei.
Less than half an hour after the strong shake a "moderate" 4.1 magnitude shock struck 20km southeast of Seddon, at a depth of 14km.
The shaking continued unabated overnight with a number of lesser magnitude quakes striking the Marlborough region.
Last night Geonet said the weekend was ending with a shake up in both islands.
There had been 125 earthquakes overnight with 6159 tremors in the past fortnight.
