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Earthquake hazard zones

The Waikato region has many active fault lines that increase the chance of earthquakes. About 20 percent of the region’s population live on soils prone to movement during earthquakes. Our map shows where earthquake fault lines are in the Waikato region and which areas are most at risk. More information is available below the map.

Waikato Regional Council's regional Ground Shaking Risk Zones and Active Fault Lines’ map uses information provided by the Institute of Geological and Nuclear Sciences (GNS). It shows active faults in the Waikato region and the extent of the Taupo Volcanic Zone. The information is used in our Waikato region Lifelines Study. You can also download this map in PDF format [PDF, 1.1 MB] below.

Map of earthquake hazard zones in the Waikato region

More information

Geological units and hazard zones

Waikato Regional Council has classified and mapped geological materials into four units used to define hazard zones1:

  1. most hazardous
  2. quite hazardous
  3. not very hazardous
  4. least hazardous.

1. Most hazardous

Materials formed less than 10,000 years ago (Holocene), such as :

  • river, lake, fan and swamp deposits
  • near coastal estuarine deposits
  • beach deposits.

These have high volcanic ash content, mixed with peat, clay, silt, ash, sand and gravel. They may include layers that are easily saturated with water and are liquefiable. The ground water table is generally very high in these areas.

2. Quite hazardous

Materials formed less than 2.5 million years ago (during the Quaternary period), made up of:

  • river and marine terrace deposits
  • lignite
  • dune sand
  • pumice
  • alluvium (gravel)
  • ignimbrite (volcanic rock) flows.

These include unsaturated, slightly weathered loose gravel, ash and sand.

3. Not very hazardous

Materials formed between 75 and 2.5 million years ago (during the Tertiary period), including:

  • sandstone
  • siltstone
  • mudstone
  • coal measures
  • limestone
  • conglomerate.

These materials are weak to moderately strong, containing volcanic rocks of various ages. Gravel is usually dense to very dense. Fine grained rocks are particularly prone to slumping and landsliding, especially if saturated or without vegetation.

4. Least hazardous

Basement rocks (more than 75 million years old) and greywacke (dark, coarse-grained sandstone), with hardened, well bedded, sandstones and siltstones (which are moderately to highly deformed), and minor schist. These materials are weak to very strong.

Find out more about Earthquakes, Subsidence and Landslides in the Waikato region.

PDF format

You can download this map from our PDF file below.

Earthquake Hazard Zones map
(1184 kb, 169 seconds to download, 56k modem)

Footnotes

  1. Waikato Regional Council commissioned the Institute of Geological and Nuclear Sciences to verify the data supporting this map. The data are mapped out at a 1:50,000 scale. Please note that the scaled down version of the original map is not accurate enough to show the boundaries between the hazard ‘zones’ clearly.