Editing Alpine Fault (section)

== History of research ==
In 1940, [[Harold Wellman]] found that the [[Southern Alps]] were associated with a fault line approximately 650&nbsp;km (400 miles)<ref group=lower-alpha name="lengthnotes"/> long.<ref name="Nathan2011">{{cite journal|last1=Nathan|first1=S.|date=2011|title=Harold Wellman and the Alpine Fault of New Zealand|url=https://www.researchgate.net/publication/273757760|journal=Episodes|volume=34|issue=1|pages=51–56|doi=10.18814/epiiugs/2011/v34i1/008|doi-access=free|access-date=6 December 2024}}</ref> The fault was officially named the Alpine Fault in 1942 as an extension of a previously mapped structure.{{sfn|Graham|2015|p=|pp=120}} At the same time, Harold Wellman proposed the {{convert|480|km|mi}} lateral displacement on the Alpine Fault. This displacement was inferred by Wellman due in part to the similarity of rocks in [[Southland, New Zealand|Southland]] and [[Nelson, New Zealand|Nelson]] on either side of the Alpine Fault. Lateral displacements of this magnitude could not be explained by pre-plate tectonics geology and his ideas were not initially widely accepted until 1956.<ref>{{cite journal|last1=Wellman|first1=H. w.|date=1956|title=Structural outline of New Zealand (No. 121)|journal=New Zealand Department of Scientific and Industrial Research, Wellington.|volume=121|issue=4}}</ref> Wellman also proposed in 1964 that the Alpine Fault was a Cenozoic structure, which was in conflict with the older Mesozoic age accepted at the time. This idea coupled with the displacement on the fault proposed that the earth's surface was in relatively rapid constant movement and helped to overthrow the old [[geosynclinal]] hypothesis in favour of plate tectonics.<ref name="Nathan2011" />

In 1964 a 25-metre-long concrete wall was built across the fault to measure the fault's movements and to find if it moves slowly over time or suddenly during big earthquakes. The wall has not moved since being built, which indicates that the build up of energy is released suddenly during large earthquakes.<ref>{{Cite web |last=Carroll |first=Joanne |date=1 February 2016 |title=Scientists hunt for clues about big Alpine Fault quake |url=https://www.stuff.co.nz/national/76403529/scientists-hunt-for-clues-about-big-alpine-fault-quake |access-date=12 April 2024 |publisher=[[Stuff (website)|Stuff]] |location=New Zealand}}</ref><ref>{{Cite web |title=The wall that Frank built |url=https://www.nzgeo.com/stories/the-wall-that-frank-built/ |access-date=2024-04-12 |website=New Zealand Geographic}}</ref>

Richard Norris and Alan Cooper from the Department of Geology, University of Otago conducted extensive research on the structure and petrology of the Alpine Fault respectively throughout the later 20th and early 21st centuries. It was during this time that the cyclicity of the Alpine Fault earthquakes and meaning of the increase in metamorphic grade towards the fault was discovered and refined.<ref>{{Cite journal|date=2003-12-01|title=Very high strains recorded in mylonites along the Alpine Fault, New Zealand: implications for the deep structure of plate boundary faults|journal=Journal of Structural Geology|volume=25|issue=12|pages=2141–2157|doi=10.1016/S0191-8141(03)00045-2|issn=0191-8141|last1=Norris|first1=Richard J.|last2=Cooper|first2=Alan F.|bibcode=2003JSG....25.2141N }}</ref> Originally this regional increase in grade was inferred to be from frictional heating along the fault not uplift of deeper geological sequences. [[Richard H. Sibson]] from the same university also used the Alpine Fault to refine his nomenclature of fault rocks which gained international adherence.<ref>{{Cite journal|last1=Atkinson|first1=B. K.|last2=White|first2=S. H.|last3=Sibson|first3=R. H.|date=1981-01-01|title=Structure and distribution of fault rocks in the Alpine Fault Zone, New Zealand|url=http://sp.lyellcollection.org/content/9/1/197|journal=Geological Society, London, Special Publications|volume=9|issue=1|pages=197–210|doi=10.1144/GSL.SP.1981.009.01.18|bibcode=1981GSLSP...9..197S |s2cid=128426863|issn=2041-4927|url-access=subscription}}</ref>

[[Chorus Limited|Chorus]]'s [[dark fibre]] cables that pass through the Alpine Fault, from the north and south of Haast, are used for [[distributed acoustic sensing]], which detects cable movement produced by earthquakes. Measurements are made using 7,250 'interrogator' locations, spaced four metres apart, which emit and detect pulses of light, generating about a gigabyte of data per minute.<ref>{{Cite news |date=25 May 2023 |title=Fibre cables offer scientists unprecedented proximity to Alpine Fault seismic zone |url=https://www.rnz.co.nz/news/national/490651/fibre-cables-offer-scientists-unprecedented-proximity-to-alpine-fault-seismic-zone |access-date=27 June 2024 |work=[[RNZ]]}}</ref><ref>{{Cite news |date=16 June 2023 |title=Seismology at light speed: how fibre-optic telecommunications cables deliver a close-up view of NZ's Alpine Fault |url=https://theconversation.com/seismology-at-light-speed-how-fibre-optic-telecommunications-cables-deliver-a-close-up-view-of-nzs-alpine-fault-206858 |access-date=27 June 2024 |work=[[The Conversation (website)|The Conversation]]}}</ref>

=== Deep Fault Drilling Project ===

The Deep Fault Drilling Project (DFDP) was an attempt in 2014 to retrieve rock and fluid samples and make geophysical measurements inside the Alpine Fault zone at depth.<ref>{{Cite journal|last=Townend|first=John|date=2009|title=Deep Fault Drilling Project—Alpine Fault, New Zealand|url=https://www.sci-dril.net/8/75/2009/sd-8-75-2009.pdf|journal=Scientific Drilling|volume=8|pages=75–82|doi=10.5194/sd-8-75-2009|bibcode=2009SciDr...8...75T |doi-access=free}}</ref><ref name="phys.org">{{Cite web|url=https://phys.org/news/2014-09-drilling-earthquake-fault-zealand.html|title=Drilling into an active earthquake fault in New Zealand|website=phys.org|access-date=2019-02-16}}</ref> It was a $2.5 million international research project designed to drill 1.3&nbsp;km to the fault plan in two months.<ref name="phys.org" /> The DFDP was the second project to try to drill an active fault zone and return samples after the [[San Andreas Fault Observatory at Depth]].<ref name="phys.org" /><ref>{{Cite news|url=https://www.theguardian.com/science/2005/dec/10/thisweekssciencequestions.geology|title=Why are scientists drilling into the San Andreas fault?|last=Ravilious|first=Kate|date=2005-12-10|work=[[The Guardian]] |access-date=2018-12-31|issn=0261-3077}}</ref> One of the goals of the project was to use the deformed rocks from the fault zone to determine its resistance to stress.<ref name="phys.org" /> Researchers also planned to install long term equipment for measuring pressure, temperature and seismic activity near the fault zone.<ref name="phys.org" /> It was led by New Zealand geologists [[Rupert Sutherland]], John Townsend and [[Virginia Toy]] and involves an international team from New Zealand, Canada, France, Germany, Japan, the United Kingdom, and the United States.<ref>{{Cite web|url=https://www.gns.cri.nz/Home/News-and-Events/Media-Releases/drill-probe-in-Alpine-Fault/DEEP-FAULT-DRILLING-PROJECT-2-FAQs|title=DEEP FAULT DRILLING PROJECT-2 FAQs / drill probe in Alpine Fault / Media Releases / News and Events / Home – GNS Science|website=gns.cri.nz|access-date=2018-12-31}}</ref>

In 2017, they reported they had discovered beneath [[Whataroa]], a small township on the Alpine Fault, "extreme" hydrothermal activity which "could be commercially very significant".<ref name="Sutherland2017"/><ref>{{cite web|url=https://www.odt.co.nz/regions/west-coast/geothermal-discovery-west-coast|title=Geothermal discovery on West Coast|date=18 May 2017|website=[[Otago Daily Times]] }}</ref> One of the lead researchers said that it is likely to be globally unique.<ref>{{Cite news|url=https://www.nzherald.co.nz/the-country/news/article.cfm?c_id=16&objectid=11858291|title=Geothermal discovery on West Coast|last=Elder|first=Vaughan|work=[[The New Zealand Herald]] |access-date=2018-12-30|issn=1170-0777}}</ref>