The Rangipo Fault (also known in the past as Desert Road Fault, Whangaehu River Fault, 'Whangaehu Fault) is the eastern

Taupō rift The Taupō Rift is the seismically active rift valley containing the Taupō Volcanic Zone, central North Island of New Zealand. Geology The Taupō Rift (Taupo Rift) is a intra-arc continental rift resulting from an oblique convergence in the H ...

-bounding north–south striking normal fault complex of the Ruapehu

Graben In geology, a graben () is a depression (geology), depressed block of the Crust (geology), crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German language, German, meaning 'ditch' or 't ...

, a seismically active area of the central

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

to the west of

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

. It could be part of a potential rupture.

Geography

It is located near the eastern side of the

Tongariro National Park Tongariro National Park (; ), located in the central North Island, is the oldest national park in New Zealand and the sixth national park established in the world.Department of Conservation"Tongariro National Park: Features", retrieved 21 April ...

, mainly in the

Rangipo Desert Te Onetapu (), commonly known as the Rangipo Desert (), is a barren desert-like environment located in New Zealand, located in the Ruapehu District on the North Island Volcanic Plateau; to the east of the three active peaks of Mount Tongariro, ...

, and traces have been now characterised on both sides of

State Highway 1 The following highways are numbered 1. For roads numbered A1, see list of A1 roads. For roads numbered B1, see list of B1 roads. For roads numbered M1, see List of M1 roads. For roads numbered N1, see list of N1 roads. For roads numbered S ...

where it is known as "''the Desert Road''" extending for at least . The northern surface traces of the fault commences just south of the Waipakihi Road to the east of the Desert Road and it extends south of the

Waiouru Military Camp Waiouru Military Camp is a camp of the New Zealand Army in the central North Island of New Zealand near Waiouru. All New Zealand Army soldiers complete their initial basic training, the All Arms Recruit Course (AARC), at Waiouru Military Camp ...

to almost the south west corner of the army training area.

Geology

The Upper Waikato Stream Fault is the eastern wall fault to its immediate north and it has been postulated that whole fault rupture of that fault, the Rangipo Fault and the potentially intersecting from the west Wahianoa Fault whose trace may be hidden under Ruapehu eruptives could result in a 7.1 M_W event. The north–south fault line transitions into the east–west alignment of the

Taupō Rift termination faults The seismically active southern end of the Taupō Rift beyond Mount Ruapehu has a number of mainly east to west orientated termination faults where the western wall Raurimu Fault and eastern wall Rangipo Fault (Desert Road Fault) terminate in ...

beyond the Ruapehu Graben with the Moawhango Fault to the east, the Shawcroft Road Fault to the west and the Snowgrass Fault to its south. Where the fault has been trenched to date it is normal with a NNE strike, and between 80°W dip. During a higher slip-rate period between 25 and 11 cal ka BP there were frequent major plinian eruptions of

so there is possibly some interaction with nearby volcanism. The long term dip slip rate from about 144 ka BP for a total displacement of is /year. However displacement since 13.8 cal ka BP has been less than /year.

Risks

The size of the characterised displacements indicates major earthquakes typical for the Taupō Rift are possible. The displacement assigned to the oldest fault rupture in the above data could be a very disruptive event. For example, the current assumed worse case is from a event rupturing this and two adjacent faults over by an average of .

References

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