Surface rupture

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Surface rupture caused by normal faulting along the Lost River Fault, during the 1983 Borah Peak earthquake Fault Scarp Borah Peak Earthquake 1983.jpg
Surface rupture caused by normal faulting along the Lost River Fault, during the 1983 Borah Peak earthquake

In seismology, surface rupture (or ground rupture, or ground displacement) is the visible offset of the ground surface when an earthquake rupture along a fault affects the Earth's surface. Surface rupture is opposed by buried rupture, where there is no displacement at ground level. This is a major risk to any structure that is built across a fault zone that may be active, in addition to any risk from ground shaking. [1] Surface rupture entails vertical or horizontal movement, on either side of a ruptured fault. Surface rupture can affect large areas of land. [2]

Contents

Lack of surface rupture

Surface rupture with folding due to reverse faulting along the Chelungpu Fault during the 1999 Jiji earthquake, Taiwan Running track after 1999 Chichi earthquake in Taiwan.jpg
Surface rupture with folding due to reverse faulting along the Chelungpu Fault during the 1999 Jiji earthquake, Taiwan

Not every earthquake results in surface rupture, particularly for smaller and deeper earthquakes. [1] In some cases, however, the lack of surface effects is because the fault that moved does not reach the surface. For example, the 1994 Northridge earthquake had a moment magnitude of 6.7, caused major damage in the Los Angeles area, occurred at 18.2 km (11 mi) below the Earth's surface, but did not cause surface rupture, because it was a blind thrust earthquake. [3]

Where surface rupture occurs

Surface ruptures commonly occur on pre-existing faults. Only rarely are earthquakes (and surface ruptures) associated with faulting on entirely new fault structures. [4] There is shallow hypocenter, and large fracture energy on the asperities, [5] the asperity shallower than 5 kilometres (3.1 mi). Examples of such earthquakes are San Fernando earthquake, Tabas earthquake, and Chi-Chi earthquake. [6]

In surface rupture earthquakes, the large slips of land are concentrated in the shallow parts of the fault. [7] And, notably, permanent ground displacements which are measureable can be produced by shallow earthquakes, of magnitude M5 and greater. [8]

Types of surface rupture

The form that surface rupturing takes depends on two things: the nature of the material at the surface and the type of fault movement.

Consequences of the Chi-Chi earthquake, Jiji, Nantou County, Taiwan Earthquake- road crack.jpg
Consequences of the Chi-Chi earthquake, Jiji, Nantou County, Taiwan

Effect of surface lithology

Where there are thick superficial deposits overlying the trace of the faults, the resulting surface effects are typically more discontinuous. Where there is little or no superficial deposits, the surface rupture is generally continuous, except where the earthquake rupture affects more than one fault, which can lead to complex patterns of surface faulting, such as in the 1992 Landers earthquake. [9]

Normal faulting

Surface ruptures associated with normal faults are typically simple fault scarps. Where there are significant superficial deposits, sections with more oblique faulting may form sets of en-echelon scarp segments. Antithetic faults may also develop, giving rise to surface grabens.

Reverse faulting

Reverse faulting (particularly thrust faulting) is associated with more complex surface rupture patterns since the protruding unsupported part of the hanging-wall of the fault is liable to collapse. In addition there may be surface folding and back-thrust development.

Strike-slip faulting

Extent of surface rupture caused by strike-slip faulting during the 2002 Denali earthquake Denali Fault surface rupture.png
Extent of surface rupture caused by strike-slip faulting during the 2002 Denali earthquake

Strike-slip faults are associated with dominantly horizontal movement, leading to relatively simple linear zones of surface rupture where the fault is a simple planar structure. However, many strike-slip faults are formed of overlapping segments, leading to complex zones of normal or reverse faulting depending on the nature of the overlap. Additionally, where there are thick superficial deposits, the rupture typically appears as a set of en-echelon faults. [10]

Mitigation

To retrofit a house to survive surface rupture requires engineered design by geotechnical, and structural or civil engineers. This can be quite expensive. [4]

Examples, with their extent

See also

Related Research Articles

<span class="mw-page-title-main">Earthquake</span> Sudden movement of the Earths crust

An earthquake is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from those that are so weak that they cannot be felt, to those violent enough to propel objects and people into the air, damage critical infrastructure, and wreak destruction across entire cities. The seismic activity of an area is the frequency, type, and size of earthquakes experienced over a particular time. The seismicity at a particular location in the Earth is the average rate of seismic energy release per unit volume. The word tremor is also used for non-earthquake seismic rumbling.

<span class="mw-page-title-main">Fault (geology)</span> Fracture or discontinuity in rock across which there has been displacement

In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep.

<span class="mw-page-title-main">1999 Düzce earthquake</span> 1999 earthquake in north-central Turkey

The 1999 Düzce earthquake occurred on 12 November at 18:57:22 local time with a moment magnitude of 7.2 and a maximum Mercalli intensity of IX (Violent), causing damage and at least 845 fatalities in Düzce, Turkey. The epicenter was approximately 100 km (62 mi) to the east of the extremely destructive 1999 İzmit earthquake that happened nearly three months earlier. Both strike-slip earthquakes were caused by movement on the North Anatolian Fault.

The 2006 Kamchatka earthquake occurred on April 21, 2006 at 12:25 PM local time. This shock had a moment magnitude of 7.6 and a maximum Mercalli intensity of X (Extreme). The hypocenter was located near the coast of Koryak Autonomous Okrug at an estimated depth of 22 km, as reported by the International Seismological Centre. This event caused damage in three villages and was followed by a number of large aftershocks. Two M6.6 earthquakes struck on April 29 at 16:58 UTC and again on May 22 at 11:12 UTC. These earthquakes caused no deaths; however, 40 people were reported injured.

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.

<span class="mw-page-title-main">1999 İzmit earthquake</span> Earthquake in Kocaeli Province, Turkey

On 17 August 1999, a catastrophic magnitude 7.6 earthquake struck the Kocaeli Province of Turkey, causing monumental damage and between 17,127 and 18,373 deaths. Named for the quake's proximity to the northwestern city of İzmit, the earthquake is also commonly referred to as the 17 August Earthquake or the 1999 Gölcük Earthquake. The earthquake occurred at 03:01 local time at a shallow depth of 15 km. A maximum Mercalli intensity of X (Extreme) was observed. The earthquake lasted for 37 seconds, causing seismic damage and is widely remembered as one of the deadliest natural disasters in modern Turkish history.

<span class="mw-page-title-main">East Anatolian Fault</span> Fault line between the Anatolian Plate and the northward-moving Arabian Plate

The East Anatolian Fault is a ~700 km long major strike-slip fault zone running from eastern to south-central Turkey. It forms the transform type tectonic boundary between the Anatolian Plate and the northward-moving Arabian Plate. The difference in the relative motions of the two plates is manifest in the left lateral motion along the fault. The East and North Anatolian faults together accommodate the westward motion of the Anatolian Plate as it is squeezed out by the ongoing collision with the Eurasian Plate.

<span class="mw-page-title-main">2002 Denali earthquake</span> 7.9 magnitude; November 3, 2002

The 2002 Denali earthquake occurred at 22:12:41 UTC November 3 with an epicenter 66 km ESE of Denali National Park, Alaska, United States. This 7.9 Mw earthquake was the largest recorded in the United States in 37 years. The shock was the strongest ever recorded in the interior of Alaska. Due to the remote location, there were no fatalities and only one injury.

<span class="mw-page-title-main">1927 Gulang earthquake</span> 1927 severe earthquake centered near Gulang, Gansu Province, China

The 1927 Gulang earthquake occurred at 6:32 a.m. on 22 May. This 7.6 magnitude event had an epicenter near Gulang, Gansu in the Republic of China. There were 40,912 deaths. It was felt up to 700 km (435 mi) away.

<span class="mw-page-title-main">Marlborough fault system</span> Active fault system in New Zealand

The Marlborough fault system is a set of four large dextral strike-slip faults and other related structures in the northern part of South Island, New Zealand, which transfer displacement between the mainly transform plate boundary of the Alpine fault and the mainly destructive boundary of the Kermadec Trench, and together form the boundary between the Australian and Pacific Plates.

The 1989 Ungava earthquake occurred at 09:24 local time on 25 December to the north of Lac Bécard in a remote part of the Ungava Peninsula in northern Quebec. It had a magnitude of 6.3 on the surface wave magnitude scale and 6.2–6.5 on the moment magnitude scale and a maximum felt intensity of only IV (Light) on the Mercalli intensity scale, due to its remoteness from any inhabited areas. The mainshock was preceded by a magnitude 5.1 foreshock ten hours earlier. It was the first earthquake in eastern North America known to be associated with ground rupture.

The 2006 Mozambique earthquake occurred at 22:19 UTC on 22 February. It had a magnitude of 7.0 on the moment magnitude scale and caused 4 deaths and 36 injuries. The epicenter was near Machaze in Manica Province of southern Mozambique, just north of the Save River. It was the largest historical earthquake in Mozambique and the first earthquake in southern Africa to have an identified surface rupture.

On December 7, 2015, an earthquake measuring 7.2 on the moment magnitude scale struck Tajikistan 105 km (65 mi) west of Murghab at 07:50 UTC at a depth of 26.0 km (16.2 mi). The earthquake was also felt in neighboring Xinjiang in China, India, Afghanistan, Pakistan and Kyrgyzstan.

The Dauki fault is a major fault along the southern boundary of the Shillong Plateau that may be a source of destructive seismic hazards for the adjoining areas, including northeastern Bangladesh. The fault, inferred to go through the southern margin of the Shillong Plateau, is an east–west-trending reverse fault inclined towards the north.

<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 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 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 1998 Zhangbei–Shangyi earthquake occurred at 11:50 local time on 10 January with a moment magnitude of 5.7 at a depth of 14.1 km. It struck the province of Hebei in Zhangjiakou. At least 70 people died, 11,500 were injured and a further 44,000 families were homeless in the wake of the event. Damage was reported in the town of Zhangbei, Hebei Province, as well as to sections of the Great Wall of China.

The 1944 Gulf of Edremit–Ayvacik earthquake occurred on October 6 at 05:34:48 local time in Balıkesir Province, Turkey. It measured 6.7 on the moment magnitude scale (Mw ) and occurred at a depth of 15 km (9 mi). The normal-faulting event had a maximum MSK-64 intensity of IX. A total of 73 people died and 275 others were injured.

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 southeast of Hilo with an approximated depth of 12 km. 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.

References

  1. 1 2 "What is Surface Rupture". USGS. Retrieved 2018-10-19.
  2. "Surface rupture can be caused by vertical or horizontal displacement". 2018-10-19.
  3. "USGS Northridge Earthquake 10th Anniversary" . Retrieved 13 April 2016.
  4. 1 2 3 "Ground Rupture & Surface Faulting - Earthquake Ground Displacement | CEA" . Retrieved Jan 1, 2020.
  5. Dalguer, Luis A.; Miyake, Hiroe; Day, Steven M.; Irikura, Kojiro. "Surface Rupturing and Buried Dynamic-Rupture Models Calibrated with Statistical Observations of Past Earthquakes". pubs.geoscienceworld.org. Retrieved 28 October 2018.{{cite web}}: CS1 maint: multiple names: authors list (link)
  6. Wada, K.; Goto, H. "Generation Mechanism of Surface and Buried Faults Considering the Effect of Plasticity in a Shallow Crust Structure" (PDF). iitk.ac.in. Retrieved 31 October 2018.{{cite web}}: CS1 maint: multiple names: authors list (link)
  7. "Differences in ground motion and fault rupture process between the surface and buried rupture earthquakes" (PDF). Earth Planets Space. 14 March 2004. Retrieved 26 October 2018.
  8. "Earthquake Processes and Effects". earthquake.usgs.gov.
  9. Zachariesen J.; Sieh K. (1995). "The transfer of slip between two en echelon strike-slip faults: A case study from the 1992 Landers earthquake, southern California" (PDF). Journal of Geophysical Research. 100 (B8): 15, 281–15, 301. Bibcode:1995JGR...10015281Z. doi:10.1029/95JB00918. hdl:10220/8475.
  10. Tchalenko J.S.; Ambraseys N.N. (1970). "Structural Analysis of the Dasht-e Bayaz (Iran) Earthquake Fractures". GSA Bulletin. 81 (1): 41–60. doi:10.1130/0016-7606(1970)81[41:SAOTDB]2.0.CO;2.
  11. Reilinger, R.E.; Ergintav S.; Bürgmann R.; McClusky S.; Lenk O.; Barka A.; Gurkan O.; Hearn L.; Feigl K.L.; Cakmak R.; Aktug B.; Ozener H. & Töksoz M.N. (2000). "Coseismic and Postseismic Fault Slip for the 17 August 1999, M = 7.5, Izmit, Turkey Earthquake" (PDF). Science . American Association for the Advancement of Science. 289 (5484): 1519–1524. Bibcode:2000Sci...289.1519R. doi:10.1126/science.289.5484.1519. PMID   10968782.
  12. "Yer kabuğundaki kayma 7 metre 30 santimetreye kadar çıktı" [The slip in the Earth's crust was up to 7 meters 30 centimeters] (in Turkish). Gazete Zebra. 15 February 2023. Retrieved 15 February 2023.