A second earthquake rattled the Marlborough area on Wednesday.
The quake, which hit about 1pm, was smaller than the 4.9 magnitude tremor recorded just before midday.
The second quake had a magnitude of 3.9.
Both quakes were centred 30km south-east of Blenheim and were 15km deep.
GNS Science says they were felt in Blenheim and Wellington.
