The 2014 Eketahuna earthquake struck at 3:52 pm on 20 January, centred 15 km east of Eketahuna on the south-east 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 coun ...

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-larges ...

. It had a maximum perceived intensity of VII (''Very strong'') on the

Mercalli intensity scale The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the ef ...

. Originally reported as magnitude 6.6 on the

Richter Scale The Richter scale —also called the Richter magnitude scale, Richter's magnitude scale, and the Gutenberg–Richter scale—is a measure of the strength of earthquakes, developed by Charles Francis Richter and presented in his landmark 1935 ...

, the earthquake was later downgraded to a magnitude of 6.2. A total of 1112 aftershocks were recorded, ranging between magnitudes 2.0 and 4.9 on the Richter Scale.

Tectonic setting

New Zealand lies along the boundary between the

Indo-Australian Plate The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...

and

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and I ...

s. In the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

most of the relative displacement between these plates is taken up along a single dextral (right lateral)

strike-slip fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectoni ...

with a major reverse component, the

Alpine Fault The Alpine Fault is a geological fault that runs almost the entire length of New Zealand's South Island (c. 480 km) and forms the boundary between the Pacific Plate and the Indo-Australian Plate. The Southern Alps have been uplifted on the f ...

. In the

the displacement is mainly taken up along the Hikurangi Subduction Zone, although the remaining dextral strike-slip component of the relative plate motion is accommodated by the North Island Fault System (NIFS). The

focal mechanism The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and ...

of the earthquake, its depth and the distribution of aftershocks show that it was a result of oblique normal faulting within the upper part of the subducting Pacific Plate, with the rupture terminating upwards at the plate interface.

Damage

It was felt strongly down the country, from

Auckland Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The most populous urban area in the country and the fifth largest city in Oceania, Auckland has an urban population of about I ...

in the north to

Dunedin Dunedin ( ; mi, Ōtepoti) is the second-largest city in the South Island of New Zealand (after Christchurch), and the principal city of the Otago region. Its name comes from , the Scottish Gaelic name for Edinburgh, the capital of Scotland. Th ...

in the south, and more than 9,000 reports were submitted by the public to GeoNet, the geological hazards monitoring network. ''

The New Zealand Herald ''The New Zealand Herald'' is a daily newspaper published in Auckland, New Zealand, owned by New Zealand Media and Entertainment, and considered a newspaper of record for New Zealand. It has the largest newspaper circulation of all newspape ...

'' newspaper reported damage to walls and chimneys and road closures in the lower North Island. The Earthquake Commission, ( EQC) received 5,013 claims, 1,514 of them from

Palmerston North Palmerston North (; mi, Te Papa-i-Oea, known colloquially as Palmy) is a city in the North Island of New Zealand and the seat of the Manawatū-Whanganui region. Located in the eastern Manawatu Plains, the city is near the north bank of the ...

. Minor to moderate damage was also reported in Eketahuna,

Wellington Wellington ( mi, Te Whanganui-a-Tara or ) is the capital city of New Zealand. It is located at the south-western tip of the North Island, between Cook Strait and the Remutaka Range. Wellington is the second-largest city in New Zealand by ...

Masterton Masterton ( mi, Whakaoriori), a large town in the Greater Wellington Region of New Zealand, operates as the seat of the Masterton District (a territorial authority or local-government district). It is the largest town in the Wairarapa, a ...

, Carterton,

Kapiti Coast The Kapiti Coast District is a local government district of the Wellington Region in the lower North Island of New Zealand, 50 km north of Wellington City. The district is named after Kapiti Island, a prominent island offshore. The pop ...

, Pahiatua, Levin and Otaki. Three 1920s-style buildings in Masterton were evacuated after cracks appeared. One building needed to be demolished. According to ''The New Zealand Herald'', two people were injured as a result of falls. Hokowhitu Lagoon in

is thought to have suffered water-bed damage leading to water leaking. Currently no fix is in place to solve this.

References

External links

Computer Simulations of Earthquake Waves
–

GNS Science GNS Science ( mi, Te Pū Ao), officially registered as the Institute of Geological and Nuclear Sciences Limited, is a New Zealand Crown Research Institute. It focuses on geology, geophysics (including seismology and volcanology), and nuclear sc ...

* {{Earthquakes in New Zealand Eketahuna earthquake 2014 earthquakes Earthquakes in New Zealand Tararua District Eketāhuna 2014 disasters in New Zealand

Tectonic setting

Damage

See also

References

External links