Centre of NZ's Extended Continental Shelf

BY JENNY BLACK (GNS)
Accessibility: difficult
Map of NZ's Extended Continental Shelf, J. Black / GNS
The centre of New Zealand's Extended Continental Shelf is in the Tararua Range, near Mt Reeves. It is marked not only by amazing views but also an artwork designed by New Zealand artist Billy Apple.
Map of NZ's Extended Continental Shelf, J. Black / GNS
The art work is located at the geographic centre of New Zealand's Extended Continental Shelf. It was designed by Billy Apple and installed by DoC and GNS Science in March 2019.

New Zealand lodged its submission under the UN Convention of the Law of the Sea (UNCLOS) in 2006. The submission establishes the precise outer limits of the ocean floor, or "continental shelf" under our jurisdiction. The boundary of the continental shelf is depicted on the art work.

The geographic centre can be thought of as the "balance point". If you were to cut out a model of NZ's continental shelf, the centre is the point it would balance at. It is a pure co-incidence that this location happens to be on land, and very special that it is in a moderately accessible location (for hikers!) with great views.

The nearby outcrops of rock along the track, reveal the underlying bedrock that makes up the Tararua ranges. It is sedimentary sandstone and mudstone (greywacke) laid down in the deep ocean off the coast of Gondwanaland, a long time before modern New Zealand was uplifted along the present day plate boundary. The Tararuas have been pushed up above the Wairarapa plains along major active faults over the last 1.5 to 2 million years. Where you are standing is located between the Wellington Fault (running up the Tauherenikau Valley to the west) and the Wairarapa Fault (at the base of the Tararuas to the east).
View from geotrip, J. Black / GNS Science
Standing on the ridge line near the artwork on a clear day, you get wide views to distant horizons. Take a look at the boundary marked on the artwork (or the image above). How much further do you think the boundary is beyond the furthest point that you can see?

We know a lot about the land area of New Zealand and our offshore islands, but most of our continent (Zealandia) is under water. What percentage of this New Zealand continent do you think is underwater?
Directions/Advisory

Park at the small DoC carpark at the end of Waiohine Valley Road, reached via Woodside Road from Greytown.

The Tararuas are notorious for wild weather. Check the forecast, carry protection from wind and rain and take great care to stick to the track.

Accessibility: DIFFICULT

Follow the Mt Reeves track (fairly well marked with DoC orange triangles). It will take 2+ hours to walk the 6 km and reach the location. This is a direct access route to or from the Tutuwai Hut in the Tauherenikau Valley. Keep your eyes out for the installation which is at ground level right beside the track (see photos).

The nearest train station is Woodside, starting from here adds nearly 4 km to the walk (each way).

Features
Landform
Geological Age
The bedrock beneath your feet was deposited around 200 million years ago
Zealandia Evolution Sequence
Eastern Province (Mesozoic growth): 300 – 110 million years ago