Landslides in New Zealand Triggered by Rainfall and Earthquakes: EGGS Webinar

Event overview

Hear from Professor Martin Brook at this free webinar organised by the Engineering Group of the Geological Society (EGGS) and the British Society of Geomorphology.

Landslides in New Zealand vary from minor earthflows and rockfalls to large, complex landslides that block river valleys and form new lakes. These landslides occur along an active plate boundary influenced by geology, geomorphology, climate, and human activity.

• The Pacific and Australian plates' oblique convergence results in thrusting, shearing, earthquakes, and rapid uplift, elevating and deforming materials.

• In the axial mountains of the North and South Islands, Mesozoic rock fractures during uplift, causing significant rock deformation, topples, slides, and rock avalanches, particularly after the November 2016 Kaikoura earthquake.

• Clay seams and crush zones, formed by flexural slip and thrusting, act as basal failure zones for deep-seated slides in Neogene weak sedimentary rock.

• Perched water tables on weathered Pleistocene ash deposits in the North Island lead to slope failures during rain in coastal areas.

• Urban fill materials are prone to failure after heavy rainfall, posing additional instability.

These landslides present significant planning and engineering challenges across New Zealand, complicating efforts for road engineers and local authorities to manage and mitigate their impact effectively.

Joining instructions

The webinar will be held on Microsoft Teams:

• Meeting ID: 251 862 247 261
• Passcode: ni9vS9Gd

There's no need to register in advance - just join the meeting on the day!