Photo: RNZ / Jamie Tahana

Where is the dead centre of New Zealand? Officially there are now two answers - Nelson and Wairarapa.

A plaque marking the geographic centre of New Zealand's Extended Continental Shelf now sits in the Tararua Ranges, 11 kilometres northwest of Greytown.

Marine geologist Cornel de Ronde told RNZ reporter Tracy Neal, it will not replace the trig point on Nelson's botanical hill, which marks the middle of the four per cent of New Zealand above land.

Dr de Ronde says the new plaque also marks a shift in how we need to see ourselves, primarily as a maritime nation.