The 2021 Khövsgöl earthquake was a magnitude 6.7 earthquake that occurred on January 12, 2021. It was located about 50 km south of the Russian border in the

Khövsgöl Lake Khövsgöl may refer to several locations in Mongolia: *Lake Khövsgöl *Khövsgöl Province Khövsgöl ( mn, Хөвсгөл) is the northernmost of the 21 aimags (provinces) of Mongolia. The name is derived from Lake Khövsgöl. Geography and ...

Tectonic setting

Mongolia has complicated tectonic and

structural geology Structural geology is the study of the three-dimensional distribution of rock units with respect to their deformational histories. The primary goal of structural geology is to use measurements of present-day rock geometries to uncover informati ...

, belonging to the Mongolian-Okhotsk Mobile Zone, between the Siberian Platform and Chinese Platform. The basement rocks formed during the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

in the

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of th ...

as Riphean age

ophiolite An ophiolite is a section of Earth's oceanic crust and the underlying upper mantle that has been uplifted and exposed above sea level and often emplaced onto continental crustal rocks. The Greek word ὄφις, ''ophis'' (''snake'') is found ...

formations experienced rifting from 1.7 to 1.6 billion years ago and again around 800 million years ago. The closing of a late Proterozoic ocean generated the ophiolites and the oldest basement rock. The Baikalides and Altaid mountain belts represent the accretion of island arcs into the

. The collision of small microcontinents like Amuria and the large collision between Asia and

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final st ...

in the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...

and

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configu ...

had a major impact on the region. Crustal extension created the Mongolian Plateau, while rifting, crustal thinning, block faulting and basalt eruptions produced terrain very similar to the

Basin and Range province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternatin ...

in the western United States. One of the strongest earthquakes in Mongolia was the 1957 Bayanhongor earthquake, which measured 8.1 and caused 30 fatalities.

Earthquake

The earthquake was the largest in

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 millio ...

since a 7.0 event in 1967. It was initially reported as 6.8 , before being downgraded to 6.7. It was located about 50 km from the Mongolian town of Turt, and 55 km from the Russian border. According to PAGER, 17,000 people felt moderate to strong shaking. It was felt as far away as Irkutsk and

Cheremkhovo Cheremkhovo ( rus, Черемхо́во, p=tɕɪrʲɪmˈxovə) is a town in Irkutsk Oblast, Russia, located on the Trans-Siberian Railway. History Cheremkhovo was founded in 1772. Administrative and municipal status Within the framework of adm ...

in Russia. It was assigned a maximum

Modified Mercalli intensity 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 effe ...

of IX (''Violent''). It was felt as far as eastern and western Siberia. The earthquake occurred due to shallow oblique-normal faulting beneath the lake along the Khuvsgul Fault. It is the largest recorded earthquake on the fault, which has the potential to generate 7.0–7.5 earthquakes. Rupture occurred on the 45°, east-dipping fault, and propagated at a speed of 2 km/s. The estimated rupture area was 40 × 20 km², and two zones of significant slip were detected. An average slip of 1 meter was inferred.

Aftershocks

At least 7 aftershocks above magnitude 5 were recorded by the

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

, With the strongest being a magnitude 5.6 on May 3, 2021.

Damage and casualties

220 public buildings around

Khövsgöl lake Khövsgöl may refer to several locations in Mongolia: *Lake Khövsgöl *Khövsgöl Province Khövsgöl ( mn, Хөвсгөл) is the northernmost of the 21 aimags (provinces) of Mongolia. The name is derived from Lake Khövsgöl. Geography and ...

and as far south as

Mörön Mörön ( mn, Мөрөн;, lit=river), also spelled Murun, is the administrative center of Khövsgöl Aimag (province) in northern Mongolia. Before 1933, Khatgal had been the aimag capital. It has 12,286 families and a population of 46,918, and ...

were damaged with cracked walls and broken windows, while two houses were completely destroyed. Although no one was killed, 59 people were injured and some had to be treated for symptoms such as heart problems and high blood pressure. Eight buildings were damaged in parts of

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eigh ...

closest to the epicentre.

References

{{Earthquakes in 2021 Earthquakes in Mongolia Khovsgol 2021 in Mongolia 2021 earthquakes in Asia 2021 in Russia Earthquakes in Russia 2021 disasters in Mongolia 2021 disasters in Russia January 2021 events in Asia January 2021 events in Russia

Tectonic setting

Earthquake

Aftershocks

Damage and casualties

See also

References