1911 Sarez earthquake
Encyclopedia
The 1911 Sarez earthquake occurred at 18:41 UTC
on 18 February (23:31 local time) in the central Pamir Mountains
in the Rushon District
of eastern Tajikistan
. It had an estimated magnitude of 7.4 on the surface wave magnitude
scale and a maximum felt intensity of about IX (violent) on the Mercalli intensity scale
. It triggered a massive landslide
, blocking the Murghab River and forming the Usoi dam
, the tallest dam in the world, creating Sarez Lake
. The earthquake and related landslides destroyed many buildings and killed about 90 people.
is located in the central Pamir Mountains
. These mountains form the western end of the Himalayan chain, caused by the continuing continental collision
between the northward moving Indian Plate and the Eurasian Plate
. The area is affected by active faulting on both thrust fault
s and strike-slip faults. The 1911 earthquake occurred within the Pamir Hindu Kush
seismic zone, which is regularly affected by earthquakes, some of which have magnitudes of 7 or greater.
an hour later. The energy radiated by this event was one of the first to be estimated from seismograph
recordings of seismic waves. Current estimates for the magnitude lie in the range 7.4–7.6 on the surface wave magnitude scale. The earthquake caused the waters of Lake Karakul to surge over its eastern rim, leaving behind a large sheet of ice as it withdrew.
s of Barchidiv, Nisur, Sagnob, Rukhch and Oroshor. The Usoi landslide completely destroyed the Usoi kishlak. Estimates of casualties from the earthquake and related landslides range from 90 to 302.
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
on 18 February (23:31 local time) in the central Pamir Mountains
Pamir Mountains
The Pamir Mountains are a mountain range in Central Asia formed by the junction or knot of the Himalayas, Tian Shan, Karakoram, Kunlun, and Hindu Kush ranges. They are among the world’s highest mountains and since Victorian times they have been known as the "Roof of the World" a probable...
in the Rushon District
Rushon district
Rushon District or Nohiya-i Rushon is a district in east Tajikistan, in the west-central part of the Gorno-Badakhshan Autonomous Province . It stretches along the Bartang River between the Yazgulem Range to the north and the Rushon Range to the south...
of eastern Tajikistan
Tajikistan
Tajikistan , officially the Republic of Tajikistan , is a mountainous landlocked country in Central Asia. Afghanistan borders it to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east....
. It had an estimated magnitude of 7.4 on the surface wave magnitude
Surface wave magnitude
The surface wave magnitude scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements in Rayleigh surface waves that travel primarily along the uppermost layers of the earth...
scale and a maximum felt intensity of about IX (violent) on the Mercalli intensity scale
Mercalli intensity scale
The Mercalli intensity scale is a seismic scale used for measuring the intensity of an earthquake. It measures the effects of an earthquake, and is distinct from the moment magnitude M_w usually reported for an earthquake , which is a measure of the energy released...
. It triggered a massive landslide
Landslide
A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...
, blocking the Murghab River and forming the Usoi dam
Usoi Dam
The Usoi Dam is a natural landslide dam along the Murghab River in the Central Asian country of Tajikistan. At high, it is the tallest dam in the world, either natural or man-made...
, the tallest dam in the world, creating Sarez Lake
Sarez Lake
-External links:****...
. The earthquake and related landslides destroyed many buildings and killed about 90 people.
Tectonic setting
The earthquake epicenterEpicenter
The epicenter or epicentre is the point on the Earth's surface that is directly above the hypocenter or focus, the point where an earthquake or underground explosion originates...
is located in the central Pamir Mountains
Pamir Mountains
The Pamir Mountains are a mountain range in Central Asia formed by the junction or knot of the Himalayas, Tian Shan, Karakoram, Kunlun, and Hindu Kush ranges. They are among the world’s highest mountains and since Victorian times they have been known as the "Roof of the World" a probable...
. These mountains form the western end of the Himalayan chain, caused by the continuing continental collision
Continental collision
Continental collision is a phenomenon of the plate tectonics of Earth that occurs at convergent boundaries. Continental collision is a variation on the fundamental process of subduction, whereby the subduction zone is destroyed, mountains produced, and two continents sutured together...
between the northward moving Indian Plate and the Eurasian Plate
Eurasian Plate
The Eurasian Plate is a tectonic plate which includes most of the continent of Eurasia , with the notable exceptions of the Indian subcontinent, the Arabian subcontinent, and the area east of the Chersky Range in East Siberia...
. The area is affected by active faulting on both thrust fault
Thrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...
s and strike-slip faults. The 1911 earthquake occurred within the Pamir Hindu Kush
Hindu Kush
The Hindu Kush is an mountain range that stretches between central Afghanistan and northern Pakistan. The highest point in the Hindu Kush is Tirich Mir in the Chitral region of Khyber-Pakhtunkhwa, Pakistan.It is the westernmost extension of the Pamir Mountains, the Karakoram Range, and is a...
seismic zone, which is regularly affected by earthquakes, some of which have magnitudes of 7 or greater.
Earthquake
The earthquake lasted for two minutes and was followed by an aftershockAftershock
An aftershock is a smaller earthquake that occurs after a previous large earthquake, in the same area of the main shock. If an aftershock is larger than the main shock, the aftershock is redesignated as the main shock and the original main shock is redesignated as a foreshock...
an hour later. The energy radiated by this event was one of the first to be estimated from seismograph
Seismometer
Seismometers are instruments that measure motions of the ground, including those of seismic waves generated by earthquakes, volcanic eruptions, and other seismic sources...
recordings of seismic waves. Current estimates for the magnitude lie in the range 7.4–7.6 on the surface wave magnitude scale. The earthquake caused the waters of Lake Karakul to surge over its eastern rim, leaving behind a large sheet of ice as it withdrew.
Landslides
The earthquake triggered numerous landslides along the slopes of the Bartang, Tanimas and Murghab valleys. The largest of these blocked the Murghab river, forming the Usoi dam and creating the Sarez and Shadau lakes. The Usoi landslide had an estimated volume of about 2 km3. The dam is the highest in the world at about 600 m, impounding a lake containing 17.5 km3 of water. The slide originated from a 4,500 m high mountain, falling 1,800 m to its present location.Damage
The area of greatest damage extended along the Bartang River from Basid in the west continuing along the Murghab River to Sarez in the east, also involving the kishlakKishlak
Kishlak or qishlaq is a rural settlement of semi-nomadis Turkic peoples of Central Asia , in Afghanistan, and in other places...
s of Barchidiv, Nisur, Sagnob, Rukhch and Oroshor. The Usoi landslide completely destroyed the Usoi kishlak. Estimates of casualties from the earthquake and related landslides range from 90 to 302.