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 count ...
's
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-largest ...
. 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 eff ...
.
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 Iza ...
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 tectonic ...
with a major
reverse
Reverse or reversing may refer to:
Arts and media
* ''Reverse'' (Eldritch album), 2001
* ''Reverse'' (2009 film), a Polish comedy-drama film
* ''Reverse'' (2019 film), an Iranian crime-drama film
* ''Reverse'' (Morandi album), 2005
* ''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
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-largest ...
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
The North Island Fault System (also known as North Island Dextral Fault Belt or NIFS) is a set of southwest–northeast trending seismically-active faults in the North Island of New Zealand that carry most of the dextral (right lateral) strike- ...
(NIFS).
The
focal mechanism 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 List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by po ...
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
GeoNet was an early international on-line services network built using microcomputers. Based on software developed in Germany by GeoNet Systems GmbH in the early 1980s, and completed in the early 1990s, it was one of the first networks to offer a ...
, 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 newspapers ...
'' 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 me ...
,
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 r ...
,
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
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,
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
Hokowhitu Lagoon, also sometimes called Centennial Lagoon, is a natural oxbow lake in the city of Palmerston North, New Zealand. Hokowhitu was created from a meander of the Manawatu River. Many features surround the lagoon including a walkway, ...
in
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 ...
is thought to have suffered water-bed damage leading to water leaking. Currently no fix is in place to solve this.
See also
*
List of earthquakes in 2014
This is a list of earthquakes in 2014. Only earthquakes of magnitude 6 or above are included, unless they result in damage and/or casualties, or are notable for some other reason. All dates are listed according to UTC time. Death toll was relat ...
*
List of earthquakes in New Zealand
This is a list of large earthquakes that have occurred in New Zealand. Only earthquakes with a magnitude of 6.0 or greater are listed, except for a few that had a moderate impact. Aftershocks are not included, unless they were of great signifi ...
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