The theory of plate tectonics is fairly well-known and at a fundamental level, fairly easy to understand. But on a recent trip to New Zealand (a country heavily shaped by plate tectonics), we pondered the question: what can you actually see if you were to look down at the boundary between two tectonic plates. New Zealand is a perfect example. The boundary between the Pacific Plate and the Indo-Australian plate is quite obvious. Here, the boundary between two plates looks like this:
This is a elevation-coloured map of the Alpine Fault near the Southern Alps in New Zealand. This fault is a direct result of the plate boundary that runs along it.
There are three types of plate boundary:
- Transform Boundary – Where the movement between plates is predominantly horizontal
- Divergent Boundary – Where two plates are moving away from each other
- Convergent Boundary – Where two plates are moving towards one another
The Alpine Fault is a result of a convergent boundary. A divergent boundary, as one would expect, creates rift valleys that look something like this:
And a convergent boundary – you guessed it – creates these guys: