Historic Hawke's Bay: Liquefaction after the 1931 Earthquake.

This photo of Westshore's Embankment Rd in Napier shows the damaging effects of liquefaction after the 1931 Hawke's Bay Earthquake.
The embankment was built mostly from mud and sand taken from the Ahuriri mud-flats - which was covered with a metre of limestone rubble, 30cm of concrete and 2.5cm of asphalt.
Both sides of Embankment Rd were retained by limestone bricks. During the earthquake and aftershocks, the unconsolidated mud and sand liquefied and laterally spread out - pushing out the supporting limestone bricks into the tidal channel.
Napier South was reclaimed in the early 1900s with silt deposits from the diverted Tutaekuri River, settling in formed embankments. Liquefaction occurred in this area during the 1931 earthquake, with water surging through the soil and houses on wooden piles sinking or tilting.
Michael Fowler's earthquake book From Disaster to Recovery is now available in eBook format from Amazon Kindle and www.mebooks.co.nz, or in hardcopy from Trade Me.