earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

struck approximately 53 kilometres SSE of the town of

Mansfield Mansfield is a market town and the administrative centre of the Mansfield District in Nottinghamshire, England. It is the largest town in the wider Mansfield Urban Area and the second largest settlement in Nottinghamshire (following the city ...

(in the vicinity of the township of

Woods Point Woods Point is a town in east-central Victoria, Australia and is located on the banks of the Goulburn River. At the , Woods Point and the surrounding area had a population of 33, down from 37 in . History The town began as a general store buil ...

), in the

Victorian Alps The Victorian Alps, also known locally as the High Country, is a large mountain system in the southeastern Australian state of Victoria. Occupying the majority of eastern Victoria, it is the southwestern half of the Australian Alps (the othe ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

on 22 September 2021, at 09:15 local time. The earthquake measured 5.9 on the

moment magnitude scale The moment magnitude scale (MMS; denoted explicitly with or Mwg, and generally implied with use of a single M for magnitude) is a measure of an earthquake's magnitude ("size" or strength) based on its seismic moment. was defined in a 1979 paper ...

. The earthquake caused minor structural damage in parts of Melbourne and left one person injured. The earthquake was also felt in

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

Australian Capital Territory The Australian Capital Territory (ACT), known as the Federal Capital Territory until 1938, is an internal States and territories of Australia, territory of Australia. Canberra, the capital city of Australia, is situated within the territory, an ...

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

and

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. The earthquake was substantially stronger than the

1989 Newcastle earthquake The 1989 Newcastle earthquake was an intraplate earthquake that occurred in Newcastle, New South Wales, on Thursday 28 December. The shock measured 5.6 on the Richter scale and was one of Australia's most serious natural disasters, killing 13 pe ...

that measured 5.6 and killed 13 people.

Tectonic setting

The Australian landmass is situated in the

Australian plate The Australian plate is or was a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately when Indi ...

, far from any known active

plate boundary Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...

, where most of the world's earthquakes occur. Such earthquakes at the plate boundary are known as

interplate earthquake An interplate earthquake occurs at the boundary between two tectonic plates. Earthquakes of this type account for more than 90 percent of the total seismic energy released around the world. If one plate is trying to move past the other, they will ...

s. In Australia, earthquakes occurring within the Australian plate are known as intraplate earthquakes because they happen within a

tectonic plate Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...

rather than at the boundary. The earthquake is situated in the

Lachlan Fold Belt The Lachlan Fold Belt (LFB) or Lachlan Orogen is a geological subdivision of the east part of Australia. It is a zone of folded and faulted rocks of similar age. It dominates New South Wales and Victoria, also extending into Tasmania, the Austr ...

, an

orogenic belt An orogenic belt, orogen, or mobile belt, is a zone of Earth's crust affected by orogeny. An orogenic belt develops when a continental plate crumples and is uplifted to form one or more mountain ranges; this involves a series of geological proc ...

consisting of folded and faulted strata. This zone formed as a result of plate convergence occurring at the eastern boundary of the

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continent, continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", ...

Gondwana Gondwana ( ; ) was a large landmass, sometimes referred to as a supercontinent. The remnants of Gondwana make up around two-thirds of today's continental area, including South America, Africa, Antarctica, Australia (continent), Australia, Zea ...

during the

Neoproterozoic The Neoproterozoic Era is the last of the three geologic eras of the Proterozoic geologic eon, eon, spanning from 1 billion to 538.8 million years ago, and is the last era of the Precambrian "supereon". It is preceded by the Mesoproterozoic era an ...

. From the Neoproterozoic to

Early Devonian The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the Pr ...

, the region was dominated by

thrusting Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that syst ...

and some

rifting In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear Fault (geology), downfaulted depression, called a graben, or more commonly ...

. Crustal deformation were later accommodated by predominantly strike-slip faulting in the

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

. One of the major strike-slip faults accommodating this deformation is the Baragwanath Transform; a

transform fault A transform fault or transform boundary, is a fault (geology), fault along a plate boundary where the motion (physics), motion is predominantly Horizontal plane, horizontal. It ends abruptly where it connects to another plate boundary, either an ...

Rifting In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear Fault (geology), downfaulted depression, called a graben, or more commonly ...

also occurred in this period, leading to

volcanism Volcanism, vulcanism, volcanicity, or volcanic activity is the phenomenon where solids, liquids, gases, and their mixtures erupt to the surface of a solid-surface astronomical body such as a planet or a moon. It is caused by the presence of a he ...

. By the

Middle Devonian In the geological timescale, the Middle Devonian epoch (from 393.3 ± 1.2 million years ago to 382.7 ± 1.6 million years ago) occurred during the Devonian period, after the end of the Emsian age. The Middle Devonian epoch is subdivided into two ...

, the Baragwanath Transform became extinct. The Governor Fault marks the northern margin of the Melbourne Zone, and southern margin of the Tabberabberan Orogeny, and is characterised by strike-slip movement. The Governor Fault is a large intraplate fault that runs from mid-western

, along part of the

Murray River The Murray River (in South Australia: River Murray; Ngarrindjeri language, Ngarrindjeri: ''Millewa'', Yorta Yorta language, Yorta Yorta: ''Dhungala'' or ''Tongala'') is a river in Southeastern Australia. It is List of rivers of Australia, Aust ...

bed and cutting through Central North

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

near

Barmah Barmah is a town in the state of Victoria, Australia. Barmah has the distinction of being located north of the border with the state of New South Wales. New South Wales is north of Victoria, with the border being the westward-flowing Murray Ri ...

to the

near

Mount Buller Mount Buller is primarily a resort town on the slopes of Mount Buller (Victoria), Mount Buller, within Mount Buller Alpine Resort, an unincorporated area of the Australian state of Victoria (Australia), Victoria. It is located approximately n ...

(near the quake epicentre) down toward the Gippsland Basin near the coast at

Saint Margaret Island Saint Margaret Island lies in Corner Inlet, in the Gippsland region of Victoria, Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Aus ...

. Tectonically this fault separates the Melbourne and Tabberabberan structural zones. An earthquake of magnitude 6.0 or larger strikes Australia about once every six to ten years, based on the seismological data collected over the past 150 years. The last-known magnitude 6.0 quake in Australia occurred in 2016 in the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

. That earthquake occurred as a result of shallow reverse faulting within the

. The largest earthquake in Australia was the mainshock of the 1988 Tennant Creek earthquakes which consisted of an 6.7 quake preceded by two > 6.0

foreshock A foreshock is an earthquake that occurs before a larger seismic eventthe mainshockand is related to it in both time and space. The designation of an earthquake as ''foreshock'', ''mainshock'' or aftershock is only possible after the full sequenc ...

Earthquake

According to the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

, the earthquake occurred on 22 September at 09:15 ACST and measured 5.9 on the moment magnitude scale. The agency also reported that the shock occurred at a depth of . It had an epicentre in

, or about northeast of Melbourne. The earthquake's location places it within the Southern Seismic Zone, a region of considerable tectonic strain. While there northwest–southeast trending faults dated to the Neogene to Quaternary, the earthquake did not occur on any of them. Furthermore

InSAR Interferometric synthetic aperture radar, abbreviated InSAR (or deprecated IfSAR), is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar (SAR) images to generate maps of surface defo ...

scans failed to locate any possible surface ruptures, indicating a deeper source for the earthquake. In 2023, seismologists published their findings in ''Seismological Research Letters'', concluding that the earthquake was caused by a rupture along an unmapped buried strike-slip fault that is oriented to the north and located at a deeper depth than the mapped faults.

Impact

According to a

geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

at the

University of Melbourne The University of Melbourne (colloquially known as Melbourne University) is a public university, public research university located in Melbourne, Australia. Founded in 1853, it is Australia's second oldest university and the oldest in the state ...

, the quake produced ten seconds of strong shaking which was felt by people. The earthquake generated shaking lasting up to a minute at the

epicentre The epicenter (), epicentre, or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. Determination The primary purpose of a s ...

region. Many residential buildings in

Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...

were evacuated due to the damage inflicted by the quake. Some damage was reported in many parts of Victoria. On

Chapel Street Chapel Street may refer to: * Chapel Street, Belgravia, England * Chapel Street, Liverpool, England * Chapel Street, Melbourne Chapel Street is a street in Melbourne, Victoria, running along the inner suburbs of South Yarra, Prahran, Windso ...

, the earthquake collapsed the top facade of Betty's Burgers & Concrete Co., which is a brick building and left debris across the road. Along Brunswick Road in Fitzroy another brick building suffered a partial collapse of its facade. At least 46 instances of building damage to chimneys and facades were reported in the city. Tall residential apartments of up to 50 storeys swayed for as much as 20 seconds, triggering panic among residents. In Mansfield near the epicentre, there was minor damage to some buildings including a local ambulance centre. Power outages were reported across parts of metropolitan Melbourne. In the town of

Mansfield, Victoria Mansfield is a town in the foothills of the Victorian Alps in the Australian state of Victoria. It is approximately north-east of Melbourne by road. The population of Mansfield was at the 2021 census. Mansfield is the seat of the Mansfi ...

, the quake caused some minor damage to buildings, resulting in no casualties. At least 40 km away is a

gold mine Gold mining is the extraction of gold by mining. Historically, mining gold from alluvial deposits used manual separation processes, such as gold panning. The expansion of gold mining to ores that are not on the surface has led to more comple ...

operated by

Kaiser Reef Kaiser ( ; ) is the title historically used by German and Austrian emperors. In German, the title in principle applies to rulers anywhere in the world above the rank of king (). In English, the word ''kaiser'' is mainly applied to the emperors ...

. When the tremors began, at least twelve mining workers were present in the mine and were brought to the surface unhurt. Kaiser Reef said that mining would cease temporarily while inspections were carried out. The company did not find any damage in the mine area. Another mine located 60 km away, and operated by

White Rock Minerals White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wavelen ...

did not find any damage to their mines after the quake. Nine workers under the mine were safely evacuated. Initially, state officials and emergency services said no casualties were caused by the earthquake, but a man in Mount Eliza, a coastal suburb in Melbourne, sustained minor injuries. The man was injured when construction fell on him while he was working.

Geoscience Australia Geoscience Australia is a statutory agency of the Government of Australia that carries out geoscientific research. The agency is the government's technical adviser on aspects of geoscience, and serves as the repository of geographic and geolo ...

said the earthquake is the strongest to hit Victoria in 50 years. It is also the largest earthquake on land in the nation since a magnitude 6.0 struck the

in 2016.

Response

Acting

Premier of Victoria The premier of Victoria is the head of government of the state of Victoria in Australia. The premier leads the Cabinet of Victoria and selects its ministers. The premier is appointed by the governor of Victoria, must be a member of the Vic ...

James Merlino James Anthony Merlino (born 19 August 1972) is a former Australian politician who served as 28th deputy premier of Victoria from 2014 to 2022 under Premier Daniel Andrews. He was the deputy leader of the Victorian branch of the Australian Lab ...

announced a statewide Watch and Act warning was in place for Victoria. The

Fire & Rescue New South Wales Fire and Rescue NSW (FRNSW) previously known as NSW Fire Brigades (NSWFB), is a agency of the New South Wales Government, Australia. FRNSW is responsible for firefighting, rescue and HAZMAT services in the major cities, metropolitan areas and ...

service stated on social media that they had received calls for assistance in the

area, but did not report any serious structural damage.

Media coverage

The earthquake made headlines in Australian news outlets the moment it occurred. ''

News Breakfast ''News Breakfast'' is an Australian news breakfast television program. It is broadcast on ABC TV and ABC News channel from 6:00 am to 9:00 am AEST or AEDT on weekdays and is hosted by James Glenday and Bridget Brennan. The program is also ...

'' was interrupted by the shaking which was video recorded. The earthquake which lasted 20 seconds in the filming studio caught hosts Michael Rowland and

Tony Armstrong Tony Patrick Armstrong (born 29 September 1989) is an Australian television presenter and former professional Australian rules footballer. He played for the Adelaide Football Club, Sydney Swans, and Collingwood Football Club in the Australian F ...

by surprise.

Further tremors

On 4 October 2021, a 2.9-magnitude tremor was felt in the Victorian town of Rawson at approximately 11:11 p.m. The following day, two further tremors were recorded, both with a 3.0 magnitude occurring at 7:17 a.m. and at 9:17 a.m. It is believed to be linked to the earthquake which occurred two weeks prior. Geoscience Australia estimates that the depth of those tremors was 8 to 10 kilometres deep.

Tectonic setting

Earthquake

Impact

Response

Media coverage

Further tremors

See also

References

Further reading