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[[File:Himalayas landsat 7.png|thumb|300x300px|Figure 1. Satellite view of the Himalayas. The Main Frontal Thrust run parallel to the glaciated peaks, north of the [[Indo-Gangetic Plain]].]] | [[File:Himalayas landsat 7.png|thumb|300x300px|Figure 1. Satellite view of the Himalayas. The Main Frontal Thrust run parallel to the glaciated peaks, north of the [[Indo-Gangetic Plain]].]] | ||
{{Infobox fault|name=Main Frontal Thrust|other_name=Himalayan Frontal Thrust|country=[[Nepal]], [[India]], [[Pakistan]], [[Bhutan]]|length=2,400 km|range=[[Himalayas]]|type=Thrust|map_image=Himalayan Tectonic Summary.png|displacement=15-21 mm/yr|status=Active|image_caption=Map of the Himalaya region with earthquakes M6+ from 1900-2014. the MFT is at the continuous black line running along}} | |||
The '''Main Frontal Thrust (MFT)''', also known as the '''Himalayan Frontal Thrust (HFT)''', is a geological [[Fault (geology)|fault]] in the [[Himalayas]] that defines the boundary between the [[Himalayan foothills]] and [[Indo-Gangetic Plain]].<ref name="Paul_&_Bhakuni_">{{Cite web|last1=Paul|first1=R.|last2=Bhakuni|first2=S.S.|title=Structural analysis of main boundary thrust and Himalayan frontal thrust around Dehra Dun, NW Himalaya: Implications of neotectonics|url=http://reports.ias.ac.in/report/18600/structural-analysis-of-main-boundary-thrust-and-himalayan-frontal-thrust-around-dehra-dun-nw-himalaya-implications-of-neotectonics|access-date=21 October 2020|website=Summer Research Fellowship Programme of India's Science Academies|archive-date=21 October 2020|archive-url=https://web.archive.org/web/20201021095249/http://reports.ias.ac.in/report/18600/structural-analysis-of-main-boundary-thrust-and-himalayan-frontal-thrust-around-dehra-dun-nw-himalaya-implications-of-neotectonics|url-status=dead}}</ref> The fault is well expressed on the surface thus could be seen via satellite imagery. It is the youngest and southernmost [[Thrust fault|thrust]] structure in the Himalaya [[Thrust tectonics|deformation front]]. It is a splay branch of the [[Main Himalayan Thrust]] (MHT) as the root [[dƩcollement]]. | |||
It runs parallel to other major splays of the MHT | ==Background== | ||
It runs parallel to other major splays of the MHT, the Main Boundary Thrust (MBT) and Main Central Thrust (MCT). The [[Sunda megathrust|Sunda Megathrust]], which extends from the Banda Islands to [[Myanmar]], is joined with the MFT.<ref name=":0">{{Cite journal |last1=Burgess |first1=W.P. |last2=Yin |first2=A. |last3=Dubey |first3=C.S. |last4=Shen |first4=ZāK. |last5=Kelty |first5=T.K. |date=2012 |title=Holocene shortening across the Main Frontal Thrust zone in the eastern Himalaya |url=https://www.researchgate.net/publication/256695341 |journal=Earth and Planetary Science Letters |volume=357ā358 |pages=152ā167 |doi=10.1016/j.epsl.2012.09.040|bibcode=2012E&PSL.357..152P }}</ref> The fault [[Strike and dip|strikes]] in a northwest-southeast direction and [[Strike and dip|dips]] at an angle of 20Ā° to 30Ā° in the north.<ref name="Wesnousky_etal_1999">{{Cite journal |last1=Wesnousky |first1=S.G. |last2=Kumar |first2=S. |last3=Mohindra |first3=R. |last4=Thakur |first4=V.C. |date=1999 |title=Uplift and convergence along the Himalayan Frontal Thrust of India |url=https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/1999TC900026 |journal=Tectonics |volume=18 |issue=6 |pages=967ā976 |doi=10.1029/1999TC900026|bibcode=1999Tecto..18..967W |s2cid=128412302 |url-access=subscription }}</ref> | |||
The | Ā | ||
The Main Boundary Thrust is another major thrust fault in the [[Himalayan orogenic zone|Himalaya orogenic]] wedge that was active in the [[Cenozoic]].<ref name="Mugnier_etal_1994">{{Cite journal |last1=Mugnier |first1=JāL. |last2=Huyghe |first2=P. |last3=Chalaron |first3=E. |last4=Mascle |first4=G. |date=1994 |title=Recent movements along the Main Boundary Thrust of the Himalayas: Normal faulting in an over-critical thrust wedge? |url=https://www.researchgate.net/publication/215614466 |journal=Tectonophysics |volume=238 |issue=1ā4 |pages=199ā215 |doi=10.1016/0040-1951(94)90056-6|bibcode=1994Tectp.238..199M }}</ref> It runs parallel to the MFT with a spacing distance of about 20 km. | |||
== Shortening rate == | == Shortening rate == | ||
Shortening rate varies across the MFT | Shortening rate varies across the MFT; these figures provide the speed in various locations.<ref name=":0" /> | ||
{| class="wikitable" | {| class="wikitable" | ||
|+ | |+ | ||
!Region | !Region | ||
!Rate (mm/yr) | !Rate (mm/yr) | ||
! | !Notes | ||
|- | |- | ||
|[[Pakistan]] | |[[Pakistan]] | ||
|14 Ā± 4 | |14 Ā± 4 | ||
| | |Minor components within the Himalayas also account for shortening. | ||
|- | |- | ||
|[[North India|Northwestern India]] | |[[North India|Northwestern India]] | ||
| | |12 Ā± 2 | ||
| | | | ||
|- | |- | ||
| Line 31: | Line 32: | ||
|- | |- | ||
|[[Bhutan]] | |[[Bhutan]] | ||
| | |17.5 Ā± 2.5 | ||
| | | | ||
|} | |} | ||
== Seismic activity == | == Seismic activity == | ||
The MFT accommodates almost the entire rate of subduction of the Indian Plate | The MFT accommodates almost the entire rate of subduction of the [[Indian Plate]]; numerous large earthquakes have occurred along this fault, and is expected to produce more in the future.<ref name=Bilham>{{Cite book|last1=Bilham |first1=R. |editor1-last=Treloar |editor1-first=P.J. |editor2-last=Searle |editor2-first=M.P. |title=Himalayan Tectonics: A Modern Synthesis |chapter=Himalayan earthquakes: a review of historical seismicity and early 21st century slip potential |series=Geological Society, London, Special Publications |year=2019 |volume=483 |pages=423ā482 |doi=10.1144/SP483.16|isbn = 9781786204059|s2cid=133821585 }}</ref> Many earthquakes associated with the MFT has resulted in visible [[Surface rupture|ground ruptures]], as seen in the [[1934 NepalāIndia earthquake|Bihar earthquake of 1934]] and [[1505 Lo Mustang earthquake|1505 magnitude 8.2ā8.8 earthquake]]. | ||
== | == References == | ||
<references /> | <references /> | ||
Latest revision as of 16:37, 2 August 2025
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.[1] The fault is well expressed on the surface thus could be seen via satellite imagery. It is the youngest and southernmost thrust structure in the Himalaya deformation front. It is a splay branch of the Main Himalayan Thrust (MHT) as the root dƩcollement.
Background[edit | edit source]
It runs parallel to other major splays of the MHT, the Main Boundary Thrust (MBT) and Main Central Thrust (MCT). The Sunda Megathrust, which extends from the Banda Islands to Myanmar, is joined with the MFT.[2] The fault strikes in a northwest-southeast direction and dips at an angle of 20Ā° to 30Ā° in the north.[3]
The Main Boundary Thrust is another major thrust fault in the Himalaya orogenic wedge that was active in the Cenozoic.[4] It runs parallel to the MFT with a spacing distance of about 20 km.
Shortening rate[edit | edit source]
Shortening rate varies across the MFT; these figures provide the speed in various locations.[2]
| Region | Rate (mm/yr) | Notes |
|---|---|---|
| Pakistan | 14 Ā± 4 | Minor components within the Himalayas also account for shortening. |
| Northwestern India | 12 Ā± 2 | |
| Nepal | 21 Ā± 1.5 | |
| Bhutan | 17.5 Ā± 2.5 |
Seismic activity[edit | edit source]
The MFT accommodates almost the entire rate of subduction of the Indian Plate; numerous large earthquakes have occurred along this fault, and is expected to produce more in the future.[5] Many earthquakes associated with the MFT has resulted in visible ground ruptures, as seen in the Bihar earthquake of 1934 and 1505 magnitude 8.2ā8.8 earthquake.
References[edit | edit source]
- ā Paul, R.; Bhakuni, S.S. "Structural analysis of main boundary thrust and Himalayan frontal thrust around Dehra Dun, NW Himalaya: Implications of neotectonics". Summer Research Fellowship Programme of India's Science Academies. Archived from the original on 21 October 2020. Retrieved 21 October 2020.
- ā 2.0 2.1 Burgess, W.P.; Yin, A.; Dubey, C.S.; Shen, ZāK.; Kelty, T.K. (2012). "Holocene shortening across the Main Frontal Thrust zone in the eastern Himalaya". Earth and Planetary Science Letters. 357ā358: 152ā167. Bibcode:2012E&PSL.357..152P. doi:10.1016/j.epsl.2012.09.040.
- ā Wesnousky, S.G.; Kumar, S.; Mohindra, R.; Thakur, V.C. (1999). "Uplift and convergence along the Himalayan Frontal Thrust of India". Tectonics. 18 (6): 967ā976. Bibcode:1999Tecto..18..967W. doi:10.1029/1999TC900026. S2CID 128412302.
- ā Mugnier, JāL.; Huyghe, P.; Chalaron, E.; Mascle, G. (1994). "Recent movements along the Main Boundary Thrust of the Himalayas: Normal faulting in an over-critical thrust wedge?". Tectonophysics. 238 (1ā4): 199ā215. Bibcode:1994Tectp.238..199M. doi:10.1016/0040-1951(94)90056-6.
- ā Bilham, R. (2019). "Himalayan earthquakes: a review of historical seismicity and early 21st century slip potential". In Treloar, P.J.; Searle, M.P. (eds.). Himalayan Tectonics: A Modern Synthesis. Geological Society, London, Special Publications. Vol. 483. pp. 423ā482. doi:10.1144/SP483.16. ISBN 9781786204059. S2CID 133821585.