Five weird things you didn't know about New Zealand

Predicting tides, making maps, managing red zone properties: it's all in a day's work for government department Land Information New Zealand.

Now it has put together a list of some of the quirkier Kiwi facts it's come across in doing its job.

1. NZ is moving at about the same speed as your fingernails grow

Because the country lies across the boundary of two tectonic plates, it's always moving in two directions, and twisting too.

Linz geodesy expert Graeme Blick said this movement averaged about 5-6cm a year - which is about how fast your fingernails grow.

2. George St is the most common street name in New Zealand

Linz keeps the official database of street addresses, which includes a whopping 74 George streets.

A good reason to make sure you put the postcode on any letters you send this year.

3. There are at least 8683 islands around our coastline

Linz's topographic maps show this many islands around the coastlines of the North, South, Stewart and the Chatham Islands, and other coastal islands.

Of these 166 are the size of Wellington's Matiu/Somes Island (250,000 sq m) or larger.

If this sounds a lot, bear in mind that this doesn't count the islands in lakes or other inland bodies of water, nor islands like the Snares and Kermadecs.

4. Most of New Zealand's place names are not official

Just because a place has a name doesn't mean it's official.

Official place names have been through the New Zealand Geographic Board.

The board makes sure place names follow a consistent and standardised approach, taking into account original Maori names, history, spelling and other factors.

Place names that are commonly used and shown in publications such as maps and charts, and which haven't been made official, are known as "recorded" names and include many of our major towns and cities such as Taupo, Timaru, New Plymouth, Greymouth, Whangarei, Wellington and many more.

There are currently nearly 16,000 official place names and about 33,000 recorded place names.

Check out the gazetteer, the board's record of New Zealand place names.

5. Pine trees and goldfish bowl weed are two of New Zealand's biggest plant pests

Pine trees play an important part of our economy, but when they spread to areas where they are unwanted, they're known as wilding pines and become an invasive pest.

Six per cent of New Zealand is now choked by wilding pines, and Linz is part of a national wildings management programme for getting rid of them.

Lagarosiphon, or oxygen weed, is another import that has inflicted our waterways.
It was brought here in the 1950s to be used in goldfish bowls, but has since found its way into many lakes and rivers and grows like, well, a weed.

Linz is managing lagarosiphon, and other invasive aquatic weeds in several lakes including Lake Wanaka and Lake Dunstan.

- NZ Herald