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The 1990 Manjil–Rudbar earthquake (Persian: زمین‌لرزه ۱۳۶۹ رودبار و منجیل) occurred on Thursday, 21 June 1990 at in the
Caspian Sea The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...
region of northern Iran. The shock had a
moment magnitude 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 ...
of 7.4 and a Mercalli Intensity of X (''Extreme''). Devastation occurred in a area, causing extensive damage in several cities. A large aftershock also added to the destruction. Between 35,000 and 50,000 people died in the earthquake; another 60,000–105,000 were injured.


Tectonic setting

Iran is one of the most seismically active regions in the world. Northwestern Iran, lies within northern part of the complex zone of
collision In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great for ...
between the Arabian plate and Eurasian plate. The Arabian plate is moving northwards relative to the Eurasian plate and the dominant style of faulting in the western Alborz Mountains involves movement on major
thrust fault A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. I ...
s, combined with subordinate left-lateral strike-slip faulting.


Earthquake

The
focal mechanism The focal mechanism of an earthquake describes the Fault (geology)#Slip.2C heave.2C throw, deformation in the Hypocenter, source region that generates the seismic waves. In the case of a Fault (geology), fault-related event, it refers to the ori ...
of the earthquake indicate that the event corresponded with left-lateral strike-slip faulting with an epicenter in
Gilan province Gilan Province () is one of the 31 provinces of Iran, in the northwest of the country and southwest of the Caspian Sea. Its capital is the city of Rasht. The province lies along the Caspian Sea, in Iran's Regions of Iran, Region 3, west of ...
. Surface rupture of about was observed along three segments of the previously unknown Rudbar Fault. Displacements estimated in the field gave an average of 60 cm left lateral motion combined with 95 cm of vertical motion, much lower than would be estimated from the observed magnitude. Optical correlation techniques using SPOT satellite imagery and aerial photographs have given estimates of 220 cm left lateral movement, better matching the magnitude and suggesting that a significant proportion of the displacement may have occurred off the main fault strand. On 22 July 1983, a 5.5 earthquake struck
Mazandaran province Mazandaran Province (; ) is one of the 31 provinces of Iran. Its capital is the city of Sari. Located along the southern coast of the Caspian Sea and in the adjacent Central Alborz mountain range and Hyrcanian forests, it is bordered clockw ...
, killing 30 people. That earthquake although situated just southwest of the 1990 earthquake's epicenter, is unlikely a
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 ...
to the 1990 event. The
Coulomb stress transfer Coulomb stress transfer is a Seismology, seismic-related geology, geological process of Stress (mechanics), stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during ...
from the 1983 source fault to the 1990 earthquake source fault was insufficient. Stress modelling showed the 1983 earthquake had decreased crustal stress in the epicenter area of the 1990 earthquake rather than increasing it.


Damage and casualties

Widespread damage occurred to the northwest of the capital city of
Tehran Tehran (; , ''Tehrân'') is the capital and largest city of Iran. It is the capital of Tehran province, and the administrative center for Tehran County and its Central District (Tehran County), Central District. With a population of around 9. ...
, including the cities of Rudbar and
Manjil Manjil () is a city in the Central District (Rudbar County), Central District of Rudbar County, Gilan province, Gilan province, Iran. History Throughout its history Manjil has been a gate to the southern Caspian Sea region. There are numero ...
. The total area of devastation was measured to be . The
National Geophysical Data Center The United States National Geophysical Data Center (NGDC) provided scientific stewardship, products and services for geophysical data describing the solid earth, marine, and solar-terrestrial environment, as well as earth observations from spac ...
estimated that $8 billion in damage occurred in the affected area. Other earthquake catalogs presented estimates of the loss of life in the range of 35,000–50,000, with a further 60,000–105,000 that were injured and 400,000 rendered homeless. The earthquake struck 30 minutes after midnight when most people were sleeping in their basic mud dwellings, a major factor contributing to the high death toll. The morning after the mainshock, a 6.5 magnitude aftershock hit the city of
Rasht Rasht (; ) is a city in the Central District (Rasht County), Central District of Rasht County, Gilan province, Gilan province, Iran, serving as the capital of the province, the county, and the district. The city is also known as the "City of ...
, causing a
dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aqua ...
to break and creating a large flood and landslide, flooding and wiping out huge swaths of farmland. Other landslides also made many roads unusable, with one landslide next to Rudbar moving up to 20 million cubic meters of land. There were at least 223 landslides recorded within a area with a total volume of . The earthquake was one of the strongest recorded in the densely populated region of the
Alborz mountains The Alborz ( ) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs northeast and merge ...
. Damage was extreme in the cities of
Manjil Manjil () is a city in the Central District (Rudbar County), Central District of Rudbar County, Gilan province, Gilan province, Iran. History Throughout its history Manjil has been a gate to the southern Caspian Sea region. There are numero ...
, and Rudbar; Khalkhal and
Nowshahr Nowshahr () is a city in the Central District of Nowshahr County, Mazandaran province, Iran, serving as capital of both the county and the district. It is a port city on the southern coast of the Caspian Sea. History Ruyan is a region in t ...
also recorded significant damage. In
Tehran Tehran (; , ''Tehrân'') is the capital and largest city of Iran. It is the capital of Tehran province, and the administrative center for Tehran County and its Central District (Tehran County), Central District. With a population of around 9. ...
, the damage was slight.
Soil liquefaction Soil liquefaction occurs when a cohesionless saturated or partially saturated soil substantially loses Shear strength (soil), strength and stiffness in response to an applied Shear stress, stress such as shaking during an earthquake or other s ...
also caused extensive damage in an area of about to the northeast of the earthquake's epicenter, ruining irrigation canals, pipelines, and splitting pavements apart. Water wells were also filled with boiled sand. In some of the smaller, hard-to-reach towns in the
Alborz mountains The Alborz ( ) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs northeast and merge ...
, there were no survivors and no house was left standing. Most buildings destroyed were unreinforced masonry buildings, or UMBs, buildings made out of unsupported brick, cinderblock or other masonry elements which will collapse during strong earthquakes like the Iran earthquake.


Tsunami

The earthquake was accompanied by a small, localized
tsunami A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, ...
in the
Caspian Sea The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...
. The waves were reported to reach 2 meters (6.5 ft) and inundated up to 1 kilometer (0.6 miles) inland. Presumably, an underwater landslide contributed to the notable tsunami, taking place on the steep shores of the continental shelf in the area. Although there were no reported casualties or severe damage in the wake of the tsunami, it reaffirmed the existence of a tsunami in the Caspian Sea and suggested that an underwater landslide that could be caused by an earthquake near the area could cause a life-threatening and potent tsunami.


Aftermath and relief efforts

The earthquake took place as Iran was recovering from the Iran-Iraq war that ended just two years prior. Due to anti-American sentiment in Iran at the time, with the earthquake taking place just 10 years after the
Iranian Revolution The Iranian Revolution (, ), also known as the 1979 Revolution, or the Islamic Revolution of 1979 (, ) was a series of events that culminated in the overthrow of the Pahlavi dynasty in 1979. The revolution led to the replacement of the Impe ...
, Iranians initially did not want to accept help from the
United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
and other western countries, but they were not in a position to launch an extensive relief effort on their own. The Iranian government and the governments that responded to the earthquake issued over 2,900 tents for the unhoused and camps for hundreds of thousands of people affected by the disaster. 170,000 blankets were also sent in to protect Iranians from the cold. An unusual outbreak of
acute renal failure Acute kidney injury (AKI), previously called acute renal failure (ARF), is a sudden decrease in kidney function that develops within seven days, as shown by an increase in serum creatinine or a decrease in urine output, or both. Causes of AKI a ...
(ARF) occurred in the aftermath of the earthquake, with the number of victims needing dialysis support rising to 156, with a mortality rate of 14 percent. Patients with ARF were more severely injured and usually had
nerve damage Nerve injury is an injury to a nerve. There is no single classification system that can describe all the many variations of nerve injuries. In 1941, Herbert Seddon introduced a classification of nerve injuries based on three main types of nerve ...
, elevated muscle enzymes, and abnormal urinalysis.


Use in media

Acclaimed Iranian director
Abbas Kiarostami Abbas Kiarostami ( ; 22 June 1940 – 4 July 2016) was an Iranian film director, screenwriter, poet, photographer, and film producer. An active filmmaker from 1970, Kiarostami had been involved in the production of over forty films, including s ...
has fictionally incorporated the earthquake and its effects on northern Iran into multiple films of his. In '' And Life Goes On'' (1992), a director and his son search for child actors from a previous Kiarostami film; '' Where Is the Friend's Home?'' (1986), which was shot in a city that, by the time of the second film's production, is recovering from the earthquake. Kiarostami's next film ''Through the Olive Trees'' (1994) follows a film crew as they shoot scenes from '' Life, and Nothing More...''; in one of these scenes a man discusses his marriage having taken place a day after the earthquake. Critics and scholars often refer to these three films as the
Koker trilogy The Koker trilogy is a series of three films directed by acclaimed Iranian film-maker Abbas Kiarostami: '' Where Is the Friend's House?'' (1987), '' Life, and Nothing More...'' (a.k.a. ''And Life Goes On'', 1992) and ''Through the Olive Trees'' ( ...
, and rank them among the director's finest works.http://www.sensesofcinema.com/2003/abbas-kiarostami/kiarostami_rural_space_and_place/, Days in the Country: Representations of Rural Space and Place in Abbas Kiarostami’s Life and Nothing More, Through the Olive Trees and The Wind Will Carry Us


See also

* List of earthquakes in 1990 *
List of earthquakes in Iran Iran is one of the most seismically active countries in the world, being crossed by several major faults that cover at least 90% of the country. As a result, earthquakes in Iran occur often and are destructive. Geology and history The Irania ...


References

Sources *


Further reading

* *


External links


7.4 – northern Iran
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 ...
* {{DEFAULTSORT:1990 Manjil-Rudbar earthquake
Man A man is an adult male human. Before adulthood, a male child or adolescent is referred to as a boy. Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromosome from the f ...
Earthquakes in Iran
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 ...
June 1990 in Iran History of Gilan 1990 disasters in Asia 1990s disasters in Iran