Roger Smith: Mapping New Zealand’s Alpine Fault

Mapping New Zealand’s Alpine Fault

Roger Smith | Geographx, New Zealand

Keywords: geomorphology, tectonics, mapping, faulting

The Alpine Fault has been described as the longest straight line on planet Earth. It runs uninterrupted for about 600km on a southwest- northeast axis along the western edge of New Zealand’s Southern Alps. The fault marks the boundary between the Australian plate to the west and the much larger Pacific plate to the east. It provides a rare example of a tectonic plate boundary lying clearly exposed on the earth’s surface.

It wasn’t until the 1940s that the Alpine Fault was first documented and investigated. This is somewhat surprising given how obvious a feature it appears when seen from the air, and how dramatically evident it stands out in modern day satellite photography.

This presentation compares past and present maps of areas bisected by the Alpine Fault, and looks at how our understanding of the fault has developed in recent years.