What s so special about New Zealand s Alpine Fault?
The Alpine Fault, which runs for about 600km up the spine of the South Island, is one of the world s major geological features. It s the “on-land” boundary of the Pacific and Australian Plates. It has ruptured four times in the past 900 years, each time producing an earthquake of about magnitude 8. Approximate rupture dates are 1717AD, 1620AD, 1450 AD, and 1100AD. Its rate of horizontal movement is about 30m per 1000 years very fast by global standards. Each time it has ruptured, it has also moved vertically, lifting the Southern Alps in the process. In the last 12 million years the Southern Alps have been uplifted by an amazing 20,000m, and it s only the fast pace of erosion that has kept their highest point below 4000m. So the fault has been responsible for building some of New Zealand s most spectacular scenery. The fault has a high probability of rupturing in the next 40 years. The rupture will produce one of the biggest earthquakes since European settlement of New Zealand, and it
