1979 Ghaenat earthquakes

Last updated
1979 Ghaenat earthquakes
Iran relief location map.jpg
Green pog.svg
Tehran
Bullseye1.png
UTC  time1979-11-14 02:21:22
 1979-11-27 17:10:32
 1979-12-07 09:24:00
ISC  event 
  655622
  656234
  653814
USGS-ANSS ComCat
  ComCat
  ComCat
Magnitude6.6 Ms , 6.8 Mw
 7.1 Ms , 7.2 Mw
Depth7.9 km [1]
Epicenter 33°57′43″N59°43′34″E / 33.962°N 59.726°E / 33.962; 59.726
Type Strike-slip
Areas affected Iran
Max. intensity MMI X (Extreme)
AftershocksMany. Largest is a Ms 6.0
Casualties297–440 dead, 279 injured

The 1979 Ghaenat earthquakes were a series of large earthquakes in Qaen County, Khorasan province, northeast Iran, near the Afghanistan border. The first mainshock, known as the Korizan earthquake with a surface-wave magnitude (Ms ) of 6.6 and moment magnitude (Mw ) of 6.8, struck on November 14, while the Ms  7.1 or Mw  7.2 Koli-Boniabad earthquake struck on November 27. [2] The two mainshocks were assigned a maximum Modified Mercalli intensity of VIII (Severe) and X (Extreme), [3] [4] respectively. The earthquakes caused extensive damage throughout northeastern Iran, killing an estimated 297 to 440 people and left at least 279 injured. [5]

Contents

Tectonic setting

Iran is situated within the Alpide belt, an active orogenic belt that spans the entire country. [6] This tectonic environment is influenced by the oblique collision of the Arabian and Eurasian Plates at an estimated rate of 22 mm/yr. [3] Iran itself is situated on the Eurasian plate, where it hosts complex zones of faults, forming tectonic blocks within the country. In southeastern Iran, the Arabian plate subducts beneath Iran along the Makran Trench. Shallow strike-slip and reverse faulting accommodate deformation in eastern Iran. Crustal shortening and thickening occur at fold and thrust belts along the Zagros, Alborz, and Kopet Dag ranges. Intraplate deformation occur, mainly displaying reverse faulting at the southern and northern parts of Iran to accommodate the convergence via crustal uplift, and strike-slip faulting at the east and western ends, where the Arabian plate slides past the adjacent crust. The tectonic setting contributes to shallow seismicity. [3]

Earthquakes

The earthquake of November 27 was the strongest in the area since 1968. Between 1968 and 1979, the area was hit by strong earthquakes including a Mw 6.0 in 1976. Another large Ms 6.7 or Mw 6.5 shock on January 16, 1979, killing 200 people in the town of Bonzonabad. [4] [7] The source fault of that event has not been identified yet although the Boznabad and Pavak faults were possible candidates. [8]

Korizan earthquake

The Ms 6.6 or Mw 6.8 earthquake of November 14 was the result of rupturing the Abiz Fault, [9] a north–south striking, right-lateral strike-slip fault at a shallow depth of 9.2 km (5.7 mi) for a length of 20 km (12 mi). [10] A maximum horizontal slip of 1 m (3 ft 3 in) and some vertical displacements were recorded during field surveys after the earthquake. [11] The southern section of the earthquake surface rupture would move once again during the 1997 Qayen earthquake. [12] The 125 km (78 mi)-long Abiz Fault ruptured in its entirety during the Mw 7.1 earthquake of 1997. [13] There were no prior recorded rupture before the 20th century. [13] [14]

Koli-Boniabad earthquake

The November 27 Ms 7.1 mainshock occurred as a result of strike-slip faulting for a length of 60 km (37 mi) along the left-lateral Dasht-e-Bayaz Fault. It had an estimated moment magnitude (Mw ) of 7.1–7.2. [6] This mainshock had a hypocenter depth of 7.9 km (4.9 mi). [1] The second rupture is nearly perpendicular to the prior rupture. [6] The same fault produced another deadly Ms 7.1 earthquake in 1968 to the west northwest. The 1968 earthquake ruptured the western section for the fault for about 80 km (50 mi) in length. At least 10 km (6.2 mi) of the 1968 rupture was involved in the 1979 event. The both earthquakes displayed strike-slip focal mechanisms. [13]

A maximum vertical surface displacement of 3.90 m (12.8 ft), and horizontal surface displacement of 2.55 m (8 ft 4 in) was measured, respectively. The epicenter located at the eastern end of the surface rupture zone suggest the fault rupture propagated westward. The eastern end of the rupture was also the intersection point of the Abiz Fault's (source of the November 14 event) northern termination. [3] During this mainshock, the northern termination of the November 14 event ruptured further northeast, joining the eastern section of the second rupture. [9] The November 14 and December 7 earthquakes ruptured approximately 35 km (22 mi) of the Abiz Fault. It was involved in a Ms 6.0 earthquake in 1936 which produced 8–12 km (5.0–7.5 mi) of surface rupture. [13]

Kalat-e-Shur earthquake

Another earthquake measuring Ms 6.0 or Mw 6.1 [15] on December 7 was initially thought to have caused a 15 km (9.3 mi) long surface rupture to the north. The aftershock would have extended the rupture length of the Abiz Fault to a total of 35 km (22 mi), but these ruptures may have also formed during a subevent of the Mw 7.2 shock. It is unlikely that the 15 km (9.3 mi) of new surface ruptures were attributed to the Mw 5.9 mainshock, due to its moderate magnitude. The earthquake has been suggested to be on a separate north–south striking structure, away from the Abiz Fault. [13]

Impact

The earthquake damaged or destroyed mainly adobe-constructed buildings of the sun-dried clay type. Strong ground motion mainly of horizontal fashion caused many walls of these structures to completely detach from its roof, resulting in a collapse. More recent construction of single-storey buildings suffered small damage and were mostly intact. In one village located along a hill, the most serious damage was observed at the summit, and appear to decrease in severity downhill, suggesting the seismic waves produced by the earthquake was amplified and reflected at higher elevations on the hill. This subjected structures at the top of the hill with more intense shaking than those on lower elevations. [16]

Between 280 and 420 people died, with a further 279 injured in the November 14 earthquake. [17] Many villages were also badly damaged in the earthquake. The earthquake struck at 5:51 local time (IST) when many adult villagers were outside their homes harvesting saffron. Most of the dead were reportedly young children left at home while their adult family members were working in the saffron fields. [16]

The second earthquake destroyed 10 villages. [4] Survivors of the earthquakes were relocated to other areas while some damaged villages were rebuilt by the government in the same place. [18] The second mainshock only resulted in 20 additional deaths and injured 24 people. The death toll from the second earthquake was smaller due to the low population density of the area when the quake struck. [19]

See also

Related Research Articles

<span class="mw-page-title-main">1946 Aleutian Islands earthquake</span> Earthquake near the Aleutian Islands, Alaska

The 1946 Aleutian Islands earthquake occurred near the Aleutian Islands, Alaska on April 1, 1946. The shock measured 8.6, Mt 9.3 or 7.4. It had a maximum Mercalli intensity of VI (Strong). It resulted in 165–173 casualties and over US$26 million in damage. The seafloor along the fault was elevated, triggering a Pacific-wide tsunami with multiple destructive waves at heights ranging from 45–138 ft (14–42 m). The tsunami obliterated the Scotch Cap Lighthouse on Unimak Island, Alaska among others, and killed all five lighthouse keepers. Despite the destruction to the Aleutian Island Unimak, the tsunami had almost an imperceptible effect on the Alaskan mainland.

The Dasht-e Bayaz and Ferdows earthquakes occurred in Dashte Bayaz, Kakhk and Ferdows, Iran in late August and early September 1968. The mainshock measured 7.1 on the moment magnitude scale and had a maximum perceived intensity of X (Extreme) on the Mercalli intensity scale. Damage was heavy in the affected areas with thousands of lives lost in the first event and many hundreds more in the second strong event.

The 1971 Bingöl earthquake was a Mw6.6–6.7 earthquake that occurred at 18:44:02 local time on 22 May. It had a surface-wave magnitude of 6.9 and a maximum intensity of IX (Violent) on the Mercalli intensity scale, killing 755–1,000 people. Bingöl was largely destroyed, as well as many houses in the nearby Bingöl plain. Surface displacement of 38 km (24 mi) and various other surficial effects were directly caused by the earthquake.

The 1930 Pyu earthquake occurred on December 4 at 01:21 local time. The epicenter was located north to Bago, Burma, then part of British India. The magnitude of the earthquake was estimated at Mw 7.3, or Ms 7.3.

An earthquake occurred in southern Mongolia on December 4, 1957, measuring Mw 7.8–8.1 and assigned XII (Extreme) on the Modified Mercalli intensity scale. Surface faulting was observed in the aftermath with peak vertical and horizontal scarp reaching 9 m (30 ft). Because of the extremely sparse population in the area, this event, despite its magnitude, was not catastrophic. However, 30 people died and the towns of Dzun Bogd, Bayan-leg and Baruin Bogd were completely destroyed.

<span class="mw-page-title-main">Haiyuan Fault</span> Intracontinental strike-slip fault in Tibet

The Haiyuan Fault is a major active intracontinental strike-slip (sinistral) fault in Central Asia.

The 1987 Superstition Hills earthquake affected the Imperial Valley of California and Baja California on November 24, nearly 12 hours after a Mw 6.0 foreshock, called the Elmore Ranch earthquake. The mainshock, measuring Mw 6.5, struck at 17:54 PST, along the Superstition Hills segment of the San Jacinto Fault Zone. The earthquake generated a 27 km (17 mi) surface rupture with additional postseismic slip continuing for a year.

On January 1, 1996, at 4:05 p.m. Central Indonesia Time, an earthquake with an epicenter in the Makassar Strait struck north of Minahasa on the island of Sulawesi, Indonesia. The earthquake measured 7.9 on the moment magnitude scale and was centered off Tolitoli Regency in Central Sulawesi, or 25 km from the Tonggolobibi village. A tsunami of 2–4 m (6.6–13.1 ft) was triggered by this earthquake as a result. At least 350 buildings were badly damaged, nine people died and 63 people were injured.

The 1968 Borrego Mountain earthquake occurred on April 8, at 18:28 PST in the geologically active Salton Trough of Southern California. The Salton Trough represents a pull-apart basin formed by movements along major faults. This region is dominated by major strike-slip faults one of them being the San Jacinto Fault which produced the 1968 earthquake. The mainshock's epicenter was near the unincorporated community of Ocotillo Wells in San Diego County. The moment magnitude (Mw ) 6.6 strike-slip earthquake struck with a focal depth of 11.1 km (6.9 mi). The zone of surface rupture was assigned a maximum Modified Mercalli intensity (MMI) of VII.

The 1902 Turkestan earthquake devastated Xinjiang, China, near the Kyrgyzstan border. It occurred on August 22, 1902, at 03:00:22 with an epicenter in the Tien Shan mountains. The thrust earthquake measured 7.7 on the moment magnitude scale (Mw ) and had a depth of 18 km (11 mi).

The 1995 Menglian earthquake or 1995 Myanmar–China earthquake occurred on 12 July at 05:46:43 local time in the Myanmar–China border region. The earthquake had an epicenter on the Myanmar side of the border, located in the mountainous region of Shan State. It registered 7.3 on the Chinese surface-wave magnitude scale (Ms ) and 6.8 on the moment magnitude scale (Mw ). With a maximum Mercalli intensity assigned at VIII, it killed 11 people and left another 136 injured. Over 100,000 homes in both countries were destroyed and 42,000 seriously damaged. Some damage to structures were also reported in Chiang Mai and Chiang Rai, Thailand. The low death toll from this earthquake was attributed to an early warning issued prior to it happening. Precursor events including foreshocks and some seismic anomalies led to an evacuation of the area before the mainshock struck. It is thought to be one of the few successfully predicted earthquakes in history.

The 1850 Xichang earthquake rocked Sichuan Province of Qing China on September 12. The earthquake which caused major damage in Xichang county had an estimated moment magnitude of 7.3–7.9 Mw  and a surface wave magnitude of 7.5–7.7 Ms . An estimated 20,650 people died.

The 1969 Alaşehir earthquake occurred on March 28 at 03:48 local time near the city of Alaşehir in Turkey's Manisa Province. The Mw  6.8 earthquake struck at 10 km (6.2 mi) depth. It had a MSK 64 intensity of VIII (Destructive). At least 53 people were killed in the earthquake.

The 1997 Bojnurd earthquake occurred on 4 February at 14:07 IRST in Iran. The epicenter of the Mw 6.5 earthquake was in the Kopet Dag mountains of North Khorasan, near the Iran–Turkmenistan border, about 579 km (360 mi) northeast of Tehran. The earthquake is characterized by shallow strike-slip faulting in a zone of active faults. Seismic activity is present as the Kopet Dag is actively accommodating tectonics through faulting. The earthquake left 88 dead, 1,948 injured, and affected 173 villages, including four which were destroyed. Damage also occurred in Shirvan and Bojnord counties. The total cost of damage was estimated to be over US$ 30 million.

The 1968 Aegean Sea earthquake was a Mw 7.0 earthquake that occurred in the early morning hours of February 20, 1968 local time about 57.1 km (35.5 mi) away from Myrina, Greece. This earthquake occurred between mainland Greece and Turkey, meaning both countries were impacted. 20 people died, and 39 people were injured to various degrees. It was the deadliest Greek earthquake since the 1956 Amorgos earthquake.

The 1977 Bob–Tangol earthquake struck Kerman province of Iran on December 20, 1977, at 03:04 Iran Standard Time. The earthquake measured Mw 5.9 and struck at a depth of 22.7 km (14.1 mi). A maximum Modified Mercalli intensity of VII was evaluated based on damage. It had a strike-slip focal mechanism, which was unusual as the source structure was a thrust fault. It was part of a sequence of strong earthquakes along the 400 km (250 mi) Kuh Banan Fault. Between 584 and 665 people perished while a further 500–1,000 were injured; thousands were also made homeless. Casualties from the earthquake was considered moderate due to the sparsely populated area it affected. Preceded by foreshocks the month before, many residents became wary of a larger earthquake and took refuge outside their homes, contributing to the moderate death toll. However, there were none immediately before the mainshock so many were still in their homes when it struck. Aftershocks were felt for several months, some causing additional damage.

An earthquake struck Western Greece near the coastal city of Aigio at 03:15:48 local time on 15 June 1995. The second destructive earthquake to strike Greece in a month, it measured 6.4–6.5 on the moment magnitude scale (Mw ). It was assigned a maximum Modified Mercalli intensity of VIII (Severe) and EMS-98 intensity of IX (Destructive). The horizontal peak ground acceleration reached 0.54 g and ground velocity peaked at 52 cm/s (20 in/s)—the strongest ground motion ever recorded in Greece. Fifteen minutes after the mainshock, a large aftershock struck, causing further damage to Aigio. Faulting occurred on either the Aigion fault or an unnamed offshore fault. Other faults in the region have the potential to produce earthquakes up to Mw  6.9, which poses a risk to Aigio and the surrounding Gulf of Corinth.

The 1983 Kaoiki earthquake struck southern Hawaii Island on the morning of November 16, 1983. Measuring Mw  6.7, it was the largest to hit the island since 1975. The epicenter was located 50 km (30 mi) southeast of Hilo with an approximated depth of 12 km (7 mi). The shallow strike-slip earthquake was assigned a maximum intensity of IX (Violent) on the Modified Mercalli scale. 6 people were injured, widespread damage and landslides were reported across the island.

The 1947 Dustabad earthquake, also known as the Charmeh earthquake, occurred in South Khorasan province of northeastern Iran on 23 September. The mainshock had a magnitude of Mw 6.9 and maximum Modified Mercalli intensity of VIII (Severe). It was accompanied by a Mw  6.1 aftershock on 26 September. These earthquakes killed an estimated 500 people.

The 1958 Firuzabad earthquake was the second destructive earthquake to strike Hamadan province, Iran, in nine months. The Mw 6.7 earthquake occurred at a depth of 15 km (9.3 mi) on 16 August at 22:43 local time. It caused severe damage to over 170 villages in the province. Due to several strong foreshocks, most of the population fled their homes and the death toll only stood at 132 and another 948 were injured. A destructive aftershock on 21 September killed another 16 people.

References

  1. 1 2 "International Seismological Centre Online Event Bibliography". ISC: On-Line Bulletin. International Seismological Centre. Retrieved 4 August 2021.
  2. ↑ National Earthquake Information Center. "M 7.1 – 56 km ENE of Q?'en, Iran". United States Geological Survey. Retrieved 4 August 2021.
  3. 1 2 3 4 Ansari, Shoja (2021). "Role of fault structural heterogeneity in nucleation location of the Mw ≥ 7 Earthquakes in Iran". Environmental Earth Sciences. 80 (730): 730. Bibcode:2021EES....80..730A. doi:10.1007/s12665-021-10042-9. S2CID   239771196.
  4. 1 2 3 National Geophysical Data Center (1972). "Search Parameters". National Centers for Environmental Information. doi:10.7289/V5TD9V7K . Retrieved 4 August 2021.{{cite journal}}: Cite journal requires |journal= (help)
  5. ↑ Carl W. Stover; Carl A. von Hake (1984). United States earthquakes, 1979, 1984, Open-File Report 84-979 (PDF). United States Geological Survey. pp. 138–140.
  6. 1 2 3 Niazi, Mansour; Kanamori, Hiroo (1981). "Source parameters of 1978 Tabas and 1979 Qainat, Iran earthquakes from long-period surface waves" (PDF). Bulletin of the Seismological Society of America . 71 (4): 1201–1213.
  7. ↑ National Earthquake Information Center. "M 6.7 – 32 km NE of Q?'en, Iran". United States Geological Survey. Retrieved 4 August 2021.
  8. ↑ Utkucu, Murat; Durmuş, Hatice; Nalbant, Süleyman (2017). "Stress history controls the spatial pattern of aftershocks: case studies from strike-slip earthquakes". International Journal of Earth Sciences. 106 (6): 1841–1861. Bibcode:2017IJEaS.106.1841U. doi:10.1007/s00531-016-1389-x. S2CID   133502859.
  9. 1 2 A. Haghipour; M. Amidi (1980). "The November 14 to December 25, 1979 Ghaenat earthquakes of northeast Iran and their tectonic implications". Bulletin of the Seismological Society of America. 70 (5): 1751–1757. Bibcode:1980BuSSA..70.1751H. doi:10.1785/BSSA0700051751.
  10. ↑ "International Seismological Centre Online Event Bibliography". ISC: On-Line Bulletin. International Seismological Centre. Retrieved 4 August 2021.
  11. ↑ Berberian, M.; Jackson, J. A.; Qorashi, M.; Khatib, M. M.; Priestley, K.; Talebian, M.; Ghafuri-Ashtiani, M. (1999). "The 1997 May 10 Zirkuh (Qa'enat) earthquake (Mw 7.2): faulting along the Sistan suture zone of eastern Iran". Geophysical Journal International. 136 (3): 671–694. Bibcode:1999GeoJI.136..671B. doi: 10.1046/j.1365-246x.1999.00762.x . S2CID   128583149.
  12. ↑ Yasutaka Ikeda; Toshifumi Imaizumi; Hiroshi Sato; Khaled Hessami; M. M. Khatib (1999). "Surface faults associated with the Qayen, northeast Iran, earthquake of May 10, 1997". Active Fault Research. 1999 (18). doi:10.11462/afr1985.1999.18_1.
  13. 1 2 3 4 5 Walker, R. T.; Bergman, E. A.; Szeliga, W.; Fielding, E. J. (2011). "Insights into the 1968-1997 Dasht-e-Bayaz and Zirkuh earthquake sequences, eastern Iran, from calibrated relocations, InSAR and high-resolution satellite imagery". Geophysical Journal International. 187 (3): 1577–1603. Bibcode:2011GeoJI.187.1577W. doi: 10.1111/j.1365-246X.2011.05213.x .
  14. ↑ Berberian, M.; Jackson, J. A.; Qorashi, M.; Khatib, M. M.; Priestley, K.; Talebian, M.; Ghafuri-Ashtiani, M. (1999). "The 1997 May 10 Zirkuh (Qa'enat) earthquake (Mw 7.2): faulting along the Sistan suture zone of eastern Iran". Geophysical Journal International. 136 (3): 671–694. Bibcode:1999GeoJI.136..671B. doi: 10.1046/j.1365-246x.1999.00762.x . S2CID   128583149.
  15. ↑ National Earthquake Information Center. "M 6.0 – 67 km ENE of Q?'en, Iran". United States Geological Survey. Retrieved 13 December 2022.
  16. 1 2 Hojjat Adeli (1981). "Ghaenat (Iran) earthquake of November 14,1979". Bulletin of the New Zealand Society for Earthquake Engineering. 14 (1). University of Teheran, Tehran, Iran: 34–36. doi: 10.5459/bnzsee.14.1.34-36 .
  17. ↑ "Korizan-Khaf Earthquake of 14 November 1979, Ms6.6". Institute of Engineering Seismology and Earthquake Engineering. 14 November 2015. Retrieved 4 August 2021.
  18. ↑ Reza Alaghebandian (1998). "Damage of Reinforced Concrete Frame Structures during the Iran-Qayen (Ardakul) Earthquake of May 10, 1997". Annual Papers on Concrete Engineering. 20 (3). Japan Concrete Engineering Association.
  19. ↑ "زمین لرزه ۶ آذر ۱۳۵۸ (۲۷ نوامبر ۱۹۷۹) کولی-بنیاباد" (in Persian). Institute of Engineering Seismology and Earthquake Engineering. Retrieved 4 August 2021.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.