Rangipo Fault
Rangipo Fault | ||
---|---|---|
Desert Road Fault, Whangaehu River Fault, Whangaehu Fault Age Quaternary | | |
Volcanic arc/belt | Taupō Volcanic Zone | |
New Zealand geology database (includes faults) |
The Rangipo Fault (also known in the past as Desert Road Fault, Whangaehu River Fault, 'Whangaehu Fault[1]) is the eastern Taupō rift-bounding north–south striking normal fault complex of the Ruapehu Graben, a seismically active area of the central North Island of New Zealand to the west of Mount Ruapehu.[1][4] It could be part of a Mw7.1 potential rupture.[3]
Geography
It is located near the eastern side of the Tongariro National Park, mainly in the Rangipo Desert, and traces have been now characterised on both sides of State Highway 1 where it is known as "the Desert Road" extending for at least 32 km (20 mi).[3] The northern surface traces of the fault commences just south of the Waipakihi Road[2] to the east of the Desert Road and it extends south of the Waiouru Military Camp to almost the south west corner of the army training area.[2]
Geology
The
Fault event Number | date of last marker before event | Displacement | Note |
---|---|---|---|
7 | 1,720 years BP | 0.1 m (3.9 in) | |
6 | 3,520 years BP | 0.14 m (5.5 in) | possible match to an Upper Waikato Stream Fault rupture[3] |
5 | 11,000 years BP | 0.8 m (2 ft 7 in) | Is about time of Pahoka–Mangamate eruption sequence (vents Ruapehu's northern summit and between Ruapehu and Tongariro).[6] |
4 | 11,000 years BP | 0.35 m (1 ft 2 in) | possible match to an Upper Waikato Stream Fault rupture[3] |
3 | 11,770 years BP | 1.2 m (3 ft 11 in) | For more than 25 km and possible match to an Upper Waikato Stream Fault rupture[3] |
2 | 11,770 years BP | 0.4 m (1 ft 4 in) | Possible match to a Wahianoa Fault rupture[3] |
1 | 13,640 years BP | 32 m (105 ft) | Match to a Wahianoa Fault rupture[3] |
Risks
The size of the characterised displacements indicates major earthquakes typical for the Taupō Rift are possible. The 32 m (105 ft) 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 Mw 7.1 event rupturing this and two adjacent faults over 43 km (27 mi) by an average of 2.4 m (7 ft 10 in).[3]
References
- ^ .
- ^ a b c New Zealand Active Fault database
- ^ S2CID 133036606.
- S2CID 55584177.
- doi:10.1130/B26000.1.
- .