Landslide FAQ

Frequently asked questions about landslides.

What are landslides?
A landslide is a natural process that removes material from hills, mountains, and coastlines, gradually lowering and flattening the topography.
What causes landslides in New Zealand?
The most common causes of landslides in New Zealand are intense rainstorms and large earthquakes. Other factors that cause significant landslides around New Zealand are weak rock, steep slopes, and deforestation.
What is New Zealand's biggest landslide?
The most significant catastrophic landslide in New Zealand is thought to be the Green Lake landslide in Fiordland. This 26km3 landslide occurred about 13,000 years ago due to the collapse of 10km of the southern Hunter mountains. It may be the world's largest rock slide.
Can landslides trigger tsunami?
Yes landslides can tsunami. Like earthquake-generated tsunami, the tsunami created by landslides are formed by the sudden displacement of water, although in this case the source comes from above rather than below. This displaced water then radiates out from the source of the disturbance as waves. A good example of this can be seen in the ripples that fan out when a stone is thrown into a pond.