Skip to main content

Story: Geomorphology – a history

Charles Cotton on film

Video file

In this film clip, New Zealand geologist Charles Cotton describes the effects of the 1945 eruption of Mt Ruapehu. At the time it seemed there would be little danger to the public because Ruapehu's crater was so isolated.

Once volcanic activity subsided the crater lake gradually refilled over the next eight years. On 24 December 1953 a lahar (volcanic mud flow) swept away the rail bridge at Tangiwai, leading to the deaths of 151 people. Cotton did not foresee such an event – but neither did anyone else at the time.

Using this item

Archives New Zealand - Te Rua Mahara o te Kāwanatanga

Reference: Weekly Review 191. National Film Unit, 1945

Permission of Archives New Zealand Te Rua Mahara o te Kāwanatanga must be obtained before any re-use of this material.

All images & media in this story

How to cite this page

Rebecca Priestley, Geomorphology – a history – Key theories: 1880s–1940s, Te Ara – the Encyclopedia of New Zealand, https://teara.govt.nz/en/video/13115/charles-cotton-on-film (accessed 4 June 2026).

Story by Rebecca Priestley, published 1 March 2009.