Scientists are deploying extra seismic instruments in Marlborough to enable more accurate measurement of the aftershocks off the coast of Seddon.
They will deploy nine instruments in coastal Marlborough over the next few days to boost the quality and quantity of data being recorded by the existing national network of instruments.
The battery-powered instruments, owned and operated by GeoNet which is funded by EQC, will be left to record for at least two weeks before the data is retrieved and analysed.
"The more accurate data will help in understanding the ruptures that are occurring and how they are linked to nearby faults off the coast of eastern Marlborough," said seismologist Stephen Bannister of GNS Science.
It was unclear if the earthquakes were occurring on a known fault or if they were occurring on an, as yet, unidentified fault, Dr Bannister said.