It would make sense to start with how New Zealand got here in the first place. The Maori people have a story, which you can see here, but I’m going to offer a slightly more scientific explanation, starting with a German guy called Alfred Wegener who proposed the idea of continental drift in 1912.
This is probably something you do know, at least roughly – unless you flunked high school science. But we’ll take another look anyway, as it’s pretty important in helping to explain New Zealand’s uniqueness. The theory goes like this:
– The surface of the Earth is made up of a crust of tectonic plates, which are floating on a fluid-like layer underneath the surface of the Earth.
– Heat from underground is moving these plates, pushing continents apart at about the rate that fingernails grow. This doesn’t seem very fast, but it has been happening over such a long time it is almost beyond imagining (over 500 million years). Over time, this movement of continents adds up to huge distances – obviously.
– Over time, this movement of the tectonic plates has lead to the formation and breaking up of the continents.
Wegener’s theory was pretty much ridiculed by his fellow geologists who failed to realise that his theory was actually right (as far as we know) until the 1950s, whence he was suddenly celebrated and held up as one of the greatest scientists of the 20th century. Too bad he’d already died by then.
The theory is supported by a wealth of evidence: The outlines of the continents actually fit together like a jigsaw puzzle if you rearrange the pieces, as you can see by my hugely detailed home-made version
Also, there are striking similarities in geological features of mountain ranges on different continents – the Appalachian Mountains in North America resemble the Caledonian Mountains in Europe, suggesting they had at some stage been part of the same land mass.
Wegener’s theory also explains how genetically similar plants have come to be on continents many thousands of kilometres apart. Our iconic New Zealand beech trees (think, the Ents in the Lord of the Rings) are closely related to beech trees in South America, and fossils in Antarctica.
New Zealand used to be a part of Gondwana, which was a supercontinent not only because it was super but also because it was really, really big. The picture above shows the present-day continents which used to form Gondwana.
New Zealand parted ways early on – about 85 million years ago – and started the slow journey to its current position in the South Pacific, where it straddles the Pacific and Indo-Australian Plates. The force of these two plates crushing together is pushing New Zealand up from between them.
This puts New Zealand in a precarious position. It is very volcanically active and unstable, as the city of Christchurch recently had the misfortune to experience first-hand (more on this later). The sharp rise of the Southern Alps from the sea illustrates nicely how strongly these plates are pushing upwards.
Here I am sitting on a West Coast beach, with New Zealand’s highest mountain, Mt. Cook/Aoraki in the background:
Picture from here.