UPDATED 9.47AM: Aftershocks have been rattling the far corner of the Gisborne region overnight, following yesterday's big 7.1 earthquake.

The tremors have been relatively small - between about 2.5 magnitude and 3.8.

Yesterday's big one was preceded by a severe 5.7 quake about 25 kilometres from Te Araroa on Thursday morning.

There's also been a magnitude 4 earthquake in the Wellington region, centered about 35 kilometres from the capital.

GNS seismologist Caroline Holden says larger magnitude aftershocks should be expected.

"The likelihood of a magnitude five, to five-point-nine is still very high, and although we haven't recorded any overnight we still expect them to be occurring quite a bit for the next seven days," she said.