The Waihi Fault Zone is a seismically active area of the central North Island of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

whose earthquakes have been associated with significant loss of life.

Geology

The intra-rift Waihi Fault Zone extends at least from Little Waihi at Lake Taupō towards

Mount Ruapehu Mount Ruapehu (; ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within the Tongari ...

on the west side of the mountain. It has two segments known as the Waihi North fault and the Waihi South fault and 19 fault strands (three of which were previously known as the Taurewa Fault). Together they make up the south western intra-rift faults of the Tongariro Graben in the Taupō Rift. The northern part of the Waihi South fault which is about long is just to the west of the recently active vents of

Mount Tongariro Mount Tongariro (; ) is a compound volcano in the Taupō Volcanic Zone of the North Island of New Zealand. It is located to the southwest of Lake Taupō, and is the northernmost of the three active volcanoes that dominate the landscape of th ...

so there is the potential for both active faulting and magmatic processes to trigger earthquakes. The fault zone has the potential to be associated with up to 7.2 magnitude earthquakes with recurrence intervals of mean 6.6 magnitude earthquakes between every 490 and 1380 years. There is now good evidence from LiDAR that it extends to the north in a three fault complex another on land or even beyond the shore line of Lake Taupo. The nearby intra-rift Poutu fault zone to the east, by about , is parallel to the Waihi fault

Risks

Large landslides have occurred in the Hipaua Steaming Cliffs area of the Waihi fault escarpment and it is likely that some the large historical loss of life by New Zealand standards from these landslides has been related to earthquake activity on the fault.

References

{{Seismic faults of New Zealand Seismic faults of New Zealand Taupō Volcanic Zone Tongariro Volcanic Centre