Editing Mount Ruapehu (section)

===Holocene activity===
<div style="float:right;">
<!--Source of most of data is Marija Voloschina 2020 and Bonadonna 2005. The number of tephra layers of the 1995-96 eruption is 2, Nagakawa 1999. Donoghue 1997. The Tn notation for Tephra layer is Voloschina 2020a and b, the Tfn notation is Donoghue 1997
---->
<timeline>
ImageSize  = width:320 height:800
PlotArea   = right:50 top:10 left:50 bottom:10
DateFormat = yyyy
TimeAxis   = orientation:vertical order:reverse
Period     = from:300 till:2050
AlignBars  = early
ScaleMajor = unit:year increment:100 start:300
Colors     = 
  id:canvas value:rgb(1,1,0.85) 
BackgroundColors = canvas:canvas
PlotData =
  width:15 color:black
  bar:test from:300 till:332 # Pre Taupo
PlotData =
  width:15 color:white
  bar:test from:332 till:1200 # Pre Maori
PlotData = 
  width:15 color:yellow
  bar:test from:1200 till:1840 # Pre accurate
PlotData = 
  width:15 color:orange
  bar:test from:1840 till:2050 # Accurate
PlotData = 
  at:305 shift:(10,0) text: Eruption 
  at:332 shift:(130,0) textcolor:red text:(&nbsp;km&nbsp;&nbsp;)
  at:332 shift:(150,5) textcolor:red fontsize:XS text:3
  at:305 shift:(100,0) textcolor:red text:Eruptive volume
  at:304 shift:(200,0) textcolor:red text:Tephra Layers 
  at:332 shift:(205,0) textcolor:red text: 6 5 4 3 2 1
  at:1995 shift:(10,-5) text: 1995–96 (T32, Tf19)
  at:1995 shift:(120,-5) textcolor:red fontsize:S text:0.004
  bar:test at:1995 mark:(line,red)
  at:1945 shift:(10,-5) text: 1945 (T31)
  at:1945 shift:(120,-5) textcolor:red fontsize:S text:0.00214
  bar:test at:1945 mark:(line,red)
  at:1835 shift:(10,-5) text: 1835 (T30, Tf18)
  at:1835 shift:(120,-5) textcolor:red fontsize:S text:0.00725
  bar:test at:1835 mark:(line,red)
  at:1788 shift:(10,-5) text: 1788  (T29, Tf17)
  at:1788 shift:(120,-5) textcolor:red fontsize:S text:0.0118
  bar:test at:1788 mark:(line,red)
  at:1747 shift:(10,-6) text: 1747 (T28, Tf16)
  at:1747 shift:(120,-6) textcolor:red fontsize:S text:0.00691
  bar:test at:1747 mark:(line,red)
  at:1735 shift:(10,-2) text: 1735 (T27, Tf15)
  at:1735 shift:(120,-2) textcolor:red fontsize:S text:0.00788
  bar:test at:1735 mark:(line,red)
  at:1655 shift:(10,-5) text: 1655 (T26)
  at:1655 shift:(120,-5) textcolor:red fontsize:S text:0.000576
  bar:test at:1655 mark:(line,red)
  at:1626 shift:(10,-5) text: 1626 (T25)
  at:1626 shift:(120,-5) textcolor:red fontsize:S text:0.004
  bar:test at:1625 mark:(line,red)
  at:1559 shift:(10,-10) text: 1559 (T24, Tf14)
  at:1559 shift:(120,-10) textcolor:red fontsize:S text:0.011
  bar:test at:1559 mark:(line,red)
  at:1540 shift:(10,-10) text: 1540 (T23, Tf13)
  at:1540 shift:(120,-10) textcolor:red fontsize:S text:0.000985
  bar:test at:1540 mark:(line,red)
  at:1526 shift:(10,-7) fontsize:S text: 1526 (T22, Tf12)
  at:1526 shift:(120,-7) textcolor:red fontsize:S text:0.00288
  bar:test at:1526 mark:(line,red)
  at:1514 shift:(10,-4) fontsize:S text: 1514 (T21, Tf11) 
  at:1514 shift:(120,-4) textcolor:red fontsize:S text:0.00301
  bar:test at:1514 mark:(line,red)
  at:1493 shift:(10,-5) fontsize:S text: 1493 (T20, Tf10)
  at:1493 shift:(120,-5) textcolor:red fontsize:S text:0.0133
  bar:test at:1493 mark:(line,red)
  at:1464 shift:(10,-8) fontsize:S text: 1464 (T19, Tf9)
  at:1464 shift:(120,-8) textcolor:red fontsize:S text:0.00591
  bar:test at:1464 mark:(line,red)
  at:1443 shift:(10,-8) fontsize:S text: 1443 (T18)
  at:1443 shift:(120,-8) textcolor:red fontsize:S text:0.000313
  bar:test at:1443 mark:(line,red)
  at:1431 shift:(10,-5) fontsize:S text: 1431 (T17, Tf8)
  at:1431 shift:(120,-5) textcolor:red fontsize:S text:0.018
  bar:test at:1431 mark:(line,red)
  at:1420 shift:(10,-2) fontsize:S text: 1420 (T16, Tf7)
  at:1420 shift:(120,-2) textcolor:red fontsize:S text:0.00218
  bar:test at:1420 mark:(line,red)
  at:1418 shift:(10,5) fontsize:S text: 1418 (T15)
  at:1418 shift:(120,5) textcolor:red fontsize:S text:0.0141
  bar:test at:1418 mark:(line,red)  
  at:1393 shift:(10,4) text: 1393 (T14)
  at:1393 shift:(120,4) textcolor:red fontsize:S text:0.000855
  bar:test at:1393 mark:(line,red)  
  at:1346 shift:(10,-5) text: 1346 (T13, Tf5)
  at:1346 shift:(120,-5) textcolor:red fontsize:S text:0.0507  
  bar:test at:1346 mark:(line,red)  
  at:1319 shift:(10,-5) text: 1319 (T12)
  at:1319 shift:(120,-5) textcolor:red fontsize:S text:0.000223
  bar:test at:1319 mark:(line,red) 
  at:1196 shift:(10,-5) text: 1196 (T11, Tf4)
  at:1196 shift:(120,-5) textcolor:red fontsize:S text:0.0181
  bar:test at:1196 mark:(line,red)
  at:1158 shift:(10,-5) text: 1158 (T10)
  at:1158 shift:(120,2) textcolor:red fontsize:S text:0.00194
  bar:test at:1158 mark:(line,red)
  at:1064 shift:(10,-5) text: 1064 (T9)
  at:1064 shift:(120,-5) textcolor:red fontsize:S text:0.00019
  bar:test at:1064 mark:(line,red) 
  at:1005 shift:(10,-5) text: 1005 (T8, Tf3)
  at:1005 shift:(120,-5) textcolor:red fontsize:S text:0.00143
  bar:test at:1005 mark:(line,red)
  at:613 shift:(10,-5) text: 613 (T7) 
  at:613 shift:(120,-5) textcolor:red fontsize:S text:0.00358
  bar:test at:613 mark:(line,red)
  at:588 shift:(10,-5) text: 588 (T6)
  at:588 shift:(120,-5) textcolor:red fontsize:S text:0.00145
  bar:test at:588 mark:(line,red)  
  at:534 shift:(10,-5) text: 534&nbsp;(T5, Tf2)
  at:534 shift:(120,-5) textcolor:red fontsize:S text:0.00251
  bar:test at:534 mark:(line,red)  
  at:456 shift:(10,-5) text: 456&nbsp;(T4)
  at:456 shift:(120,-5) textcolor:red fontsize:S text: 0.00379
  bar:test at:456 mark:(line,red)
  at:379 shift:(10,-10) text: 379 (T3)
  at:379 shift:(120,-10) textcolor:red fontsize:S text:0.000172
  bar:test at:379 mark:(line,red)
  at:370 shift:(10,-4) text: 370 (T2, Tf1)
  at:370 shift:(120,-4) textcolor:red fontsize:S text:0.00932
  bar:test at:370 mark:(line,red)
  at:366 shift:(10,5) text: 366 (T1)
  at:366 shift:(120,5) textcolor:red fontsize:S text:0.000215
  bar:test at:366 mark:(line,red) 
  at:1230 shift:(10,-5) textcolor:black text: Māori in NZ 
  bar:test at:1200 mark:(line,black) 
  at:1860 shift:(10,-5) textcolor:black text: European colonisation
  bar:test at:1840 mark:(line,black)
LineData =
  at:366 frompos:310 tillpos:320 color:red width:2
  at:370 frompos:310 tillpos:320 color:red width:2
  at:379 frompos:310 tillpos:320 color:red width:2
  at:456 frompos:290 tillpos:320 color:red width:2
  at:534 frompos:310 tillpos:320 color:red width:2
  at:588 frompos:310 tillpos:320 color:red width:2
  at:613 frompos:310 tillpos:320 color:red width:2
  at:1005 frompos:310 tillpos:320 color:red width:2
  at:1064 frompos:310 tillpos:320 color:red width:2
  at:1158 frompos:310 tillpos:320 color:red width:2
  at:1196 frompos:290 tillpos:320 color:red width:2
  at:1319 frompos:310 tillpos:320 color:red width:2
  at:1346 frompos:260 tillpos:320 color:red width:2
  at:1393 frompos:310 tillpos:320 color:red width:2
  at:1418 frompos:270 tillpos:320 color:red width:2
  at:1420 frompos:310 tillpos:320 color:red width:2
  at:1431 frompos:260 tillpos:320 color:red width:2
  at:1443 frompos:310 tillpos:320 color:red width:2
  at:1464 frompos:270 tillpos:320 color:red width:2
  at:1493 frompos:260 tillpos:320 color:red width:2
  at:1514 frompos:300 tillpos:320 color:red width:2
  at:1526 frompos:300 tillpos:320 color:red width:2
  at:1540 frompos:310 tillpos:320 color:red width:2
  at:1559 frompos:290 tillpos:320 color:red width:2
  at:1626 frompos:300 tillpos:320 color:red width:2
  at:1655 frompos:310 tillpos:320 color:red width:2
  at:1735 frompos:300 tillpos:320 color:red width:2
  at:1747 frompos:300 tillpos:320 color:red width:2
  at:1788 frompos:290 tillpos:320 color:red width:2
  at:1835 frompos:300 tillpos:320 color:red width:2
  at:1945 frompos:290 tillpos:320 color:red width:2
  at:1995 frompos:300 tillpos:320 color:red width:2
 </timeline>
<small>Medium size [[tephra]] eruptions of Ruapehu since the 232 CE<br />Taupo eruption<ref name="Voloschina2020a"/><ref name="Bonadonna2005">{{cite journal|last1=Bonadonna |first1= C.|last2= Houghton |first2= B.F. |title=Total grain-size distribution and volume of tephra-fall deposits| journal=Bulletin of Volcanology|volume= 67|pages= 441–456 |year=2005 |issue= 5|doi=10.1007/s00445-004-0386-2|bibcode= 2005BVol...67..441B|s2cid= 53386767}}</ref><ref name="Nagakawa 1999"/><ref name="Donoghue 1997">{{cite journal|last1=C|first1= S. L.|last2= Neall |first2= V. E. |last3=Palmer |first3= A. S. |last4=Stewart |first4= R. B. |year=1997 |title= The volcanic history of Ruapehu during the past 2 millenia based on the record of Tufa Trig tephras| journal= Bulletin of Volcanology |volume= 59 |issue= 2|pages=136–146 |doi=10.1007/s004450050181|bibcode= 1997BVol...59..136D|s2cid= 128492446}}</ref></small>
</div>

Lava flows that have been erupted from Ruapehu since the [[Last Glacial Maximum|last glacial maximum]] are called the Whakapapa Formation. These flows all erupted between 15,000 and 2,000 years ago from a number of different craters on the summit of Ruapehu as well as from craters on the northern and southern flanks of the mountain.<ref name="Hackett1985" /><ref name="Price2012" /> Rangataua on the southern flanks had a large lava flow between 15,000 and 10,000 years ago.<ref>{{cite journal|last1 =Doll|first1 =P.|last2 =Eaves|first2 =S.R.|last3 =Kennedy|first3 =B.M.|last4 =Blard|first4 =P.H.|last5 =Nichols|first5 =A.R.L.|last6 =Leonard|first6 =G.S.|last7 =Townsend|first7 =D.B.|last8 =Cole|first8 =J.W.|last9 = Conway|first9 =C.E.|last10 =Baldwin|first10 =S.|last11 =Fénisse|first11 =G.|year =2024|title =Cosmogenic 3 He chronology of postglacial lava flows at Mt Ruapehu, Aotearoa/New Zealand|journal =Geochronology|volume = 6|issue =3|pages = 365–395|doi =10.5194/gchron-6-365-2024|doi-access=free|bibcode =2024GeChr...6..365D}}</ref>

Approximately 10,000 years ago, a series of major eruptions occurred, not just on Ruapehu, but also at the [[Tama Lakes]] between Ruapehu and [[Tongariro]] volcanoes. This period of intense eruptions is called the Pahoka-Mangamate event and is thought to have lasted between 200 and 400 years.<ref name="Nairn 1998">{{cite journal |last1=Nairn |first1=Ian A |last2=Kobayashi |first2=Tetsuo |last3=Nakagawa |first3=Mitsuhiro |title=The ~10 ka multiple vent pyroclastic eruption sequence at Tongariro Volcanic Centre, Taupo Volcanic Zone, New Zealand |journal=Journal of Volcanology and Geothermal Research |date=November 1998 |volume=86 |issue=1–4 |pages=19–44 |doi=10.1016/S0377-0273(98)00085-7}}</ref> On Ruapehu, lava was erupted from Saddle Cone—a flank crater on the northern slopes—and from another crater on the southern slopes. This southern crater erupted three times, and lava flows from this crater travelled nearly 14&nbsp;km to the south.<ref name="Hackett1985" /><ref name="Price2012" />

There is evidence that a [[sector collapse]] on the northwestern slopes about 9,400 years ago formed the amphitheatre that now comprises the [[Whakapapa skifield]] and left an extensive avalanche deposit on the northwestern ring plain that can still be seen today.<ref name="Price2012" /> Since then eruptions have been an order of magnitude lower in intensity and volume.<ref name="Pardo2012">{{cite journal |last1=Pardo |first1=Natalia |last2=Cronin |first2=Shane J. |last3=Palmer |first3=Alan S. |last4=Németh |first4=Karoly |title=Reconstructing the largest explosive eruptions of Mt. Ruapehu, New Zealand: lithostratigraphic tools to understand subplinian–plinian eruptions at andesitic volcanoes |journal=Bulletin of Volcanology |date=2011-10-27 |volume=74 |issue=3 |pages=617–640 |doi=10.1007/s00445-011-0555-z |s2cid=129769124}}</ref> Accordingly, most of the {{cvt|150|km3|cumi}} cone and {{cvt|150|km3|cumi}} ring-plain is older than 10,000 years.<ref name="RuapehuTongariro2021Review" /> Eruptions between 10,000 and 2,500 years ago generated lava flows that all flowed into the Whakapapa amphitheatre and created the slopes of the modern skifield.<ref name="Price2012" />

For the past 2,000 years, activity at Ruapehu has been largely focused through a crater lake at the summit.<ref name="Gamble2003" /> Eruptive activity has typically consisted of relatively small but explosive [[phreatomagmatic eruption]]s occurring every few decades and lasting several months each.<ref name="Gamble2003" /><ref name="Price2012" /> The eruptive record is only well understood from [[tephra]] deposits before 1950 for 1718 years from the Taupō [[Hatepe eruption]] in 232 CE. Over this period there are 30 assigned tephra units by composition studies to Ruapehu and in the 370 years before 1950 the mean time between these months of eruptive period was 40 years.<ref name="Voloschina2020a">{{cite thesis|first1=Marija |last1=Voloschina |title=Eruption dynamics and frequency-magnitude relationships of explosive eruptions at Mt. Ruapehu, New Zealand over the past 1800 years : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand|url=https://mro.massey.ac.nz/handle/10179/16439 |year =2000 |access-date=2023-04-16}}</ref><ref name="Voloschina2020b">{{cite journal|first1=Marija |last1=Voloschina |first2=Gert |last2=Lube |first3=Jonathan |last3=Procter |first4= Anja |last4=Moebis |first5= Christian |last5=Timm |title=Lithosedimentological and tephrostratigraphical characterisation of small-volume, low-intensity eruptions: The 1800 years Tufa Trig Formation, Mt. Ruapehu (New Zealand) |journal=Journal of Volcanology and Geothermal Research |volume=402 |year=2020 |issn=0377-0273 |doi=10.1016/j.jvolgeores.2020.106987 |bibcode=2020JVGR..40206987V |s2cid=224945660 |url=https://www.sciencedirect.com/science/article/pii/S0377027320301475 }}</ref>

In recorded history, these eruptions have occurred about 50&nbsp;years apart, in 1895 ([[lahar]]),<ref name="Blot1979">{{cite journal|first1=Claude |last1=Blot |year=1979 |title= Deep earthquakes that were precursors of the eruption of Ruapehu, New Zealand on 22 June 1969 |journal= New Zealand Journal of Geology and Geophysics| volume=22 |issue=3 |pages= 413–414 |doi=10.1080/00288306.1979.10424110 |bibcode=1979NZJGG..22..413B }}</ref> 1945 and 1995–1996.<ref name="GNS" /> Minor [[phreatic eruption|phreatic]] or hydrothermal eruptions occur every few years on average, with notable minor eruptions occurring in 1969, 1975, and 2007.<ref name="Kilgour2010" /><ref name="Nairn 1979" /> More than 600 eruptive events of various sizes have been documented since 1830.<ref name="Scott 2013" />