The Main Himalayan Thrust (MHT) is a

décollement Décollement () is a gliding plane between two rock masses, also known as a basal detachment fault. Décollements are a deformational structure, resulting in independent styles of deformation in the rocks above and below the fault. They are ass ...

under the

Himalaya Range The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

. This thrust fault follows a NW-SE

strike Strike may refer to: People * Strike (surname) Physical confrontation or removal *Strike (attack), attack with an inanimate object or a part of the human body intended to cause harm *Airstrike, military strike by air forces on either a suspected ...

, reminiscent of an arc, and gently dip towards the north, beneath the region. It is the largest active continental megathrust fault in the world.

Overview

The MHT accommodates

crustal shortening Thrust tectonics or contractional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the shortening and thickening of the crust or lithosphere. It is one of the three main types of tectonic regime, ...

of India and Eurasia as a result of the ongoing collision between the

Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

and

Eurasian Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipela ...

plates. Deformation of the crust is also accommodated along

splay Splay may refer to: *Splay, a verb meaning slant, slope or spread outwards * Splay (physiology), the difference between urine threshold and saturation * Splay (Japanese band), a J-pop band from Osaka * Splay Networks, a Sweden-headquartered grou ...

structures including the

Main Frontal Thrust The Main Frontal Thrust (MFT), also known as the Himalayan Frontal Thrust (HFT) is a geological fault in the Himalayas that defines the boundary between the Himalayan foothills and Indo-Gangetic Plain. The fault is well expressed on the surfac ...

(MFT), Main Boundary Thrust (MBT),

Main Central Thrust The Main Central Thrust is a major geological fault where the Indian Plate has pushed under the Eurasian Plate along the Himalaya. The fault slopes down to the north and is exposed on the surface in a NW-SE direction (strike). It is a thrust fault ...

(MCT) and possibly the

South Tibetan Detachment The South Tibetan Detachment is one of the major Fault (geology), faults in the Himalaya Mountains. Background Understanding the formation of the Himalayan mountains has been a goal of structural geologists for a long time. Many of the problems an ...

. The MHT is the root detachment of these splays. At this present moment, the MFT and MHT accounts for almost the entire rate of

convergence Convergence may refer to: Arts and media Literature *''Convergence'' (book series), edited by Ruth Nanda Anshen * "Convergence" (comics), two separate story lines published by DC Comics: **A four-part crossover storyline that united the four Wei ...

(15-21 mm/yr). This fault defines where the India subcontinent is underthrust beneath the Himalayan orogenic wedge. In April 2015, a section of the MHT produced a blind rupture earthquake, killing nearly 9,000 Nepalese.

Associated seismicity

The Main Himalayan Thrust and its splay branches has been the source of numerous earthquakes, including some that are indirectly related. {, class="wikitable" , + !Date !Country !Magnitude !Depth (km) ! MMI !Deaths !Comments !Source , - , 1255-06-07 , Nepal , 8.0+ , - , , , 800 km of rupture. Killed one-third of Nepal's population , , - , 1344-09-14 , Nepal , , - , , , , , - , 1408 , Nepal , , - , , , , , - , 1505-06-06 , Nepal, India and China , 8.2–8.8 , - , , , Killed 30% of the Nepalese population , , - , 1680 , Nepal , <7.5 , - , , , , , - , 1714-05-4 , Bhutan , 7.6–8.6 , - , IX , "Many" , Ruptured the whole Bhutan section of the

, , - , 1803-09-01 , India , 7.8–7.9 , - , IX , 300 , Damage as far as New Delhi. , , - , 1833-08-26 , Nepal , 7.5–7.9 , - , IX , 500 , Severely damaged Kathmandu and was felt as far as Calcutta. , , - , 1905-04-04 , India , 7.9 , - , X , 20,000+ , , , - , 1934-01-05 , Nepal and India , 8.1 , 15.0 , XI , 12,000 , Ruptured to the surface via the Main Frontal Thrust , , - , 1947-07-29 , China , 7.3 , 20.0 , V , , , , - , 1950-08-15 , India, China and Myanmar , 8.6 , 15.0 , XI , 4,800 , , , - , 1966-06-27 , Nepal and India , 6.1 , 37.0 , , 80 , , , - , 1980-07-29 , Nepal and India , 6.5 , 17.5 , VIII , 200 , , , - , 1988-08-21 , Nepal , 6.9 , 57.4 , VIII , 700-1400 , , , - , 1991-10-20 , India , 6.8 , 10.3 , IX , 2000 , Main Central Thrust , , - , 1999-03-29 , India , 6.8 , 21.0 , VII , 103 , , , - , 2005-10-08 , Pakistan , 7.6 , 26.0 , XI , 87,400 , , , - , 2009-09-21 , Bhutan , 6.1 , 14.0 , VI , 11 , , , - , 2011-09-18 , India , 6.9 , 50.0 , VII , 111 , Intraplate strike-slip , , - , 2013-05-01 , Pakistan and India , 5.7 , 15.0 , VII , 1 , Additional 59 injured. , , - , 2015-04-25 , Nepal , 7.8 , 8.2 , VIII , 8,964 , , , - , 2015-05-12 , Nepal , 7.3 , 18.5 , VIII , 218 , Aftershock of the April 2015 earthquake , , - , 2015-07-24 , Pakistan , 5.1 , 17.0 , V , 3 , , , - , 2019-09-24 , Pakistan , 6.0 , 10.0 , VII , 40 , , {{cite journal , first1=K.M. , last1=Sreejith , first2=M.C.M. , last2=Jasir , first3=R. , last3=Agrawal , first4=A.S. , last4=Rajawat , title=The 2019 September 24, Mw = 6, Mirpur earthquake, NW Himalaya: Geodetic evidence for shallow, near-horizontal décollement rupture of the Main Himalayan Thrust , journal= Tectonophysics , year=2021 , volume=816 , issue=229013 , doi=10.1016/j.tecto.2021.229013 , url=https://www.sciencedirect.com/science/article/abs/pii/S004019512100295X , publisher= Elsevier

References

Tectonics Himalayas Active faults Structural geology Seismic faults Seismic faults of Asia Thrust faults Seismic faults of Pakistan Geology of the Himalaya Subduction zones Geology of Nepal Geology of Asia Geology of India Geology of Pakistan Geology of China Geology of Bhutan

Overview

Associated seismicity

See also

References