2001 Kunlun earthquake

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2001 Kunlun earthquake
2001 Kunlun earthquake shakemap.jpg
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UTC  time2001-11-14 09:26:10
ISC  event 2331800
USGS-ANSS ComCat
Local date14 November 2001 (2001-11-14)
Local time17:26
Magnitude7.8 Mw
8.0 Ms [1]
Depth15 km (9.3 mi)
Epicenter 36°12′N90°54′E / 36.200°N 90.900°E / 36.200; 90.900
Fault Kunlun Fault
Type Strike-slip
Areas affected China
Max. intensity MMI IX (Violent)
Casualtiesnone

An earthquake occurred in China on 14 November 2001 at 09:26 UTC (17:26 local time), with an epicenter near Kokoxili, close to the border between Qinghai and Xinjiang in a remote mountainous region. With a magnitude of 7.8 Mw (8.0 Ms ), it was the most powerful earthquake in China for 5 decades. [2] No casualties were reported, presumably due to the very low population density and the lack of high-rise buildings. This earthquake was associated with the longest surface rupture ever recorded on land, ~450 km. [3]

Contents

Tectonic setting

The Kunlun fault is one of the major sinistral strike-slip structures that accommodate the eastward motion of the Tibetan Plateau relative to the Eurasian Plate. This motion is caused by the lateral spreading of the zone of thickened crust associated with the collision between the Indian and Eurasian Plates. [4]

Earthquake

Major fault zones around the Tibetan Plateau showing location of Kunlun fault TibetanPlateauTectonics.png
Major fault zones around the Tibetan Plateau showing location of Kunlun fault

The earthquake rupture began on a relatively small strike-slip fault segment at the western end of the Kunlun fault in the region of the mountain Buka Daban Feng. The rupture propagated to the east via an extensional stepover before following the main strand of the Kunlun fault. The region of co-seismic deformation (i.e. that occurred during the earthquake) is unusually large, with significant faulting being observed up to 60 km from the main rupture trace. [5] This deformation occurs in two swathes, ca. 20 and 60 km from the main fault trace. Pre-existing lineaments and geomorphological features suggest that this earthquake-triggered displacement occurred on existing faults. The co-seismic surface rupture extended for more than 400 km, making it the longest zone of co-seismic surface rupture so far observed. [6]

An analysis of the propagation speed indicates that the rupture propagated at a normal velocity along the original segment, but increased in velocity to above the S wave velocity after the jump across the extensional stepover and continued at that speed until propagation stopped. [7] This makes the Kunlun earthquake the best documented example of a supershear earthquake. It has been suggested that the unusually wide zone of co-seismic deformation is a direct result of the supershear rupture propagation. [8]

Damage

Due to the remoteness of the region, most reports of damage came from areas hundreds of kilometers from the epicenter. The nearest population centre, the city of Golmud, reported severe shaking but no buildings collapsed. Some damage was reported at the construction site for the Qinghai–Tibet railway [4] and along the Qinghai–Tibet highway. [2]

See also

Related Research Articles

Strike-slip tectonics or wrench tectonics is a type of tectonics that is dominated by lateral (horizontal) movements within the Earth's crust. Where a zone of strike-slip tectonics forms the boundary between two tectonic plates, this is known as a transform or conservative plate boundary. Areas of strike-slip tectonics are characterised by particular deformation styles including: stepovers, Riedel shears, flower structures and strike-slip duplexes. Where the displacement along a zone of strike-slip deviates from parallelism with the zone itself, the style becomes either transpressional or transtensional depending on the sense of deviation. Strike-slip tectonics is characteristic of several geological environments, including oceanic and continental transform faults, zones of oblique collision and the deforming foreland of zones of continental collision.

In seismology, a supershear earthquake is an earthquake in which the propagation of the rupture along the fault surface occurs at speeds in excess of the seismic shear wave (S-wave) velocity. This causes an effect analogous to a sonic boom.

<span class="mw-page-title-main">Kunlun Fault</span>

The Kunlun Fault is a major active left-lateral strike-slip fault to the north side of Tibet. Slippage along the 1,500-kilometre-long (930 mi) fault has occurred at a constant rate for the last 40,000 years. This has resulted in a cumulative offset of more than 400 metres (1,300 ft). The fault is seismically active, most recently causing the magnitude 7.8 2001 Kunlun earthquake. It forms the northeastern boundary of the elongate wedge of the Tibetan Plateau known as the Bayan Har block.

In seismology, an earthquake rupture is the extent of slip that occurs during an earthquake in the Earth's crust. Earthquakes occur for many reasons that include: landslides, movement of magma in a volcano, the formation of a new fault, or, most commonly of all, a slip on an existing fault.

<span class="mw-page-title-main">Xianshuihe fault system</span> Geological feature in Asia

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<span class="mw-page-title-main">Main Himalayan Thrust</span> Geological feature

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<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.

On July 17, 2017, an earthquake struck near the Komandorski Islands, east of the Kamchatka Peninsula in the Bering Sea at. Although there were no casualties from this earthquake, it was notable for a rare characteristic known as supershear, and is one of the few times a large supershear earthquake has been observed. It was preceded by a few foreshocks months earlier, and aftershocks that continued for nearly six months.

<span class="mw-page-title-main">2013 Craig, Alaska earthquake</span> Earthquake in Alaska and British Columbia

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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 1906 Manasi earthquake (玛纳斯地震), also known as the Manas earthquake occurred in the morning of December 23, 1906, at 02:21 UTC+8:00 local time or December 22, 18:21 UTC. It measured 8.0–8.3 on the moment magnitude scale and 8.3 on the surface-wave magnitude scale. The epicenter of this earthquake is located in Manas County, Xinjiang, China. An estimated 280–300 people died and another 1,000 more were injured by the earthquake.

The 1990 Gonghe earthquake occurred on April 26 at 17:37 China Standard Time in Hainan Tibetan Autonomous Prefecture, Qinghai Province. The mainshock had a surface wave magnitude of 7.0 Ms  and a moment magnitude of 6.5 Mw . It was presaged by two foreshocks that struck merely seconds before the main earthquake. On the Mercalli intensity scale, the earthquake had a rating of IX (Violent).

The 2021 Maduo earthquake, also known as the 5.22 earthquake struck Madoi County in Qinghai Province, China on 22 May at 02:04 local time. The earthquake had a moment magnitude and surface-wave magnitude of 7.4. Highway bridges, roads and walls collapsed as a result of the earthquake. According to an anonymous source, at least 20 people were killed, 300 were injured, and 13 were missing. Officials stated that there were no deaths but 19 people sustained minor injuries. It was the strongest in China since 2008. It was assigned a maximum intensity of X in Machali, Maduo County on the China seismic intensity scale and Modified Mercalli intensity scale. This earthquake was preceded by another unrelated earthquake that occurred 5 hours earlier in Yunnan.

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 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. The two mainshocks were assigned a maximum Modified Mercalli intensity of VIII (Severe) and X (Extreme), respectively. The earthquakes caused extensive damage throughout northeastern Iran, killing an estimated 297 to 440 people and left at least 279 injured.

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 1923 Renda earthquake occurred on March 24 at 20:40 local time between the counties of Daofu and Luhuo in Sichuan, China. The estimated Ms 7.3 earthquake was assigned a maximum modified Mercalli intensity scale rating of X (Extreme). Severe damage occurred in Sichuan, killing an estimated 4,800 people.

The 1955 Zheduotang earthquake, also known as the Kangding earthquake occurred on April 14 at 09:29:02 local time near the city of Kangding in the Garzê Tibetan Autonomous Prefecture, Sichuan. The earthquake had a moment magnitude of 7.0 and a surface wave magnitude of 7.1 and struck at a depth of 10 km. Severe damage occurred in Kangding with the loss of 70 lives.

References

  1. ↑ "Earthquake Event: QINGHAI, CHINA". ngdc.noaa.gov.
  2. 1 2 Li Li; Chen Yong (2002). "Preliminary report on the Ms 8.1 Kokoxili (Qinghai, China) earthquake of 14 November 2001". Episodes. 25 (2): 95–99. doi: 10.18814/epiiugs/2002/v25i2/005 .
  3. ↑ Klinger,Y.; Xu,X.; Tapponnier,P.; Van der Woerd,J.; Lasserre,C.; Geoffrey King,G. (2005). "High-Resolution Satellite Imagery Mapping of the Surface Rupture and Slip Distribution of the Mw _7.8, 14 November 2001 Kokoxili Earthquake, Kunlun Fault, Northern Tibet, China". Bulletin of the Seismological Society of America. 95 (5): 1970–1987. Bibcode:2005BuSSA..95.1970K. doi:10.1785/0120040233.
  4. 1 2 Van Der Woerd J.; Meriaux, A.S.; Klinger, Y.; Ryerson, F.J.; Gaudemer, Y.; Tapponnier, P. (2002). "The 14 November 2001, Mw 7.8 Kokoxili earthquake in northern Tibet (Qinghai Province, China)" (PDF). Seismological Research Letters. 73 (2): 125–135. Bibcode:2002SeiRL..73..125V. doi:10.1785/gssrl.73.2.125. Archived from the original (PDF) on 1 September 2020. Retrieved 30 January 2019.
  5. ↑ Liu, J. G.; Haselwimmer, C. E. (2006). "Co-seismic ruptures found up to 60 km south of the Kunlun fault after 14 November 2001, Ms 8.1, Kokoxili earthquake using Landsat-7 ETM+ imagery". International Journal of Remote Sensing. 27 (20): 4461–4470. Bibcode:2006IJRS...27.4461L. doi:10.1080/01431160600784283. S2CID   140636365.
  6. ↑ Fu B.; Lin A. (2003). "Spatial distribution of the surface rupture zone associated with the 2001 Ms 8.1 Central Kunlun earthquake, northern Tibet, revealed by satellite remote sensing data". International Journal of Remote Sensing. 24 (10): 2191–2198. Bibcode:2003IJRS...24.2191F. doi:10.1080/0143116031000075918. S2CID   128499961.
  7. ↑ Bouchon,M.; Vallee,M. (2003). "Observation of Long Supershear Rupture During the Magnitude 8.1 Kunlunshan Earthquake". Science. 301 (5634): 824–6. Bibcode:2003Sci...301..824B. doi:10.1126/science.1086832. PMID   12907799. S2CID   26437293.
  8. ↑ Bouchon, Michel; Karabulut,H., Hayrullah (6 June 2008). "The Aftershock Signature of Supershear Earthquakes". Science. 320 (5881): 1323–1325. Bibcode:2008Sci...320.1323B. doi:10.1126/science.1155030. PMID   18535239. S2CID   206511510.
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