Ruapehu

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 39.28°S
  • 175.57°E

  • 2797 m
    9174 ft

  • 241100
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

6 March-12 March 2013

On 12 March, GeoNet reported that the Volcanic Alert Level for Ruapehu remained at 1 (signs of volcano unrest) and the Aviation Colour Code was lowered to Green based on the analysis of monitoring data and the lack of recent seismic activity.

Source: New Zealand GeoNet Project



 Available Weekly Reports


2013: February | March
2012: November
2011: March | April
2008: September
2007: March | September | October
2006: October
2004: November
2002: January | December
2001: February | November


6 March-12 March 2013

On 12 March, GeoNet reported that the Volcanic Alert Level for Ruapehu remained at 1 (signs of volcano unrest) and the Aviation Colour Code was lowered to Green based on the analysis of monitoring data and the lack of recent seismic activity.

Source: New Zealand GeoNet Project


27 February-5 March 2013

On 5 March, GeoNet reported that monitoring of the Ruapehu Crater Lake showed that temperatures at depth remained above background levels but had started a declining trend. Gas data from January and February showed emission rates of 15-25 tonnes per day of sulfur dioxide and around 650 tonnes per day carbon dioxide; these are within the usual range of emissions measured at Ruapehu. Seismicity remained low, characterized by weak volcanic tremor and some shallow earthquakes. Areas of discoloration in the lake, sometimes observed during the previous few weeks, are relatively common and thought to reflect internal lake convection processes. Scientists speculated that there was a partial blockage between the deep and shallow systems causing the lake temperature to remain steady; the relatively low temperature of Crater Lake, 22-25°C since March 2012, is one of the longest periods of low lake temperatures recorded. The Volcanic Alert Level remained at 1 (signs of volcano unrest) and the Aviation Colour Code remained at Yellow.

Source: New Zealand GeoNet Project


28 November-4 December 2012

On 3 December, GeoNet reported that monitoring data suggested that Ruapehu continued in a state of unrest. Scientists aboard an overflight observed that the crater lake was quiet and that the temperature remained steady at 22 degrees Celsius. Seismicity had decreased since the early part of November. The Volcanic Alert Level remained at 1 (signs of volcano unrest) and the Aviation Colour Code remained at Yellow.

Source: New Zealand GeoNet Project


21 November-27 November 2012

On 23 November, GeoNet reported that measurements of Ruapehu's crater lake taken on 21 November suggested that conditions had not changed since the previous week and that Ruapehu was in a state of unrest. The Volcanic Alert Level remained at 1 (signs of volcano unrest) and the Aviation Colour Code remained at Yellow.

Source: New Zealand GeoNet Project


14 November-20 November 2012

GeoNet reported that measurements at Ruapehu during the previous few weeks indicated that the likelihood of an eruption had increased. Scientists were concerned that increased heat at depth beneath the crater indicated a partialyl blocked vent and the potential for an eruption due to increased pressure. On 16 November the Volcanic Alert Level remained at 1 (signs of volcano unrest) and the Aviation Colour Code was raised to Yellow.

Source: New Zealand GeoNet Project


7 November-13 November 2012

On 5 November, GeoNet reported that Ruapehu's summit Crater Lake was hot during field visits in December 2011 and January 2012, exhibiting temperatures over 35 degrees Celsius. The lake cooled afterwards, reaching 16 degrees in May and fluctuating between 18-24 degrees during June-October. Scientists visited the lake in late October and reported that the water temperature was 19.5 degrees. During that visit they observed weak convection near the center of the blue-green lake.

GeoNet noted that Ruapehu is often seismically active; during the last month weak volcanic tremor was recorded and more recently several small earthquakes under the volcano had been detected. The largest earthquake was an M 2.

An overflight on 26 October to measure gas flux revealed that sulfur dioxide was 63 tonnes per day and carbon dioxide was 908 tonnes per day. The Aviation Colour Code remained at Green and the Volcanic Alert Level remained at 1 (signs of volcano unrest).

Source: New Zealand GeoNet Project


27 April-3 May 2011

On 2 May, GeoNet reported that the temperature of Ruapehu's summit Crater Lake continued to slowly cool and was about 30 degrees Celsius, down from a peak of 41 degrees in March. The lake level remained below the overflow level and no earthquakes had been located within 10 km of the Crater Lake for two weeks. The Aviation Colour Code was lowered to Green and the Volcanic Alert Level remained at 1 (signs of volcano unrest).

Source: New Zealand GeoNet Project


20 April-26 April 2011

On 18 April, GeoNet reported that the temperature of Ruapehu's summit Crater Lake was slowly cooling and decreased to 33-34 degrees Celsius from a peak of 41 degrees in March. A general decline of activity had been noted since 4 April, including lower carbon dioxide gas flux, less seismicity, modest change in the Crater Lake water chemistry, and cessation of lake overflow accompanying the start of the cooling trend. The Aviation Colour Code remained at Yellow and the Volcanic Alert Level remained at 1 (signs of volcano unrest).

Source: New Zealand GeoNet Project


30 March-5 April 2011

On 5 April, GeoNet reported that the temperature of Ruapehu's summit Crater Lake had been high for a sustained period and was currently between 38 and 39 degrees Celsius. The highest temperature since unrest began in October 2010 was 41 degrees Celsius, measured on 1 March. The report also noted that during the previous few weeks there was an increase in carbon dioxide gas emissions, increased seismicity, and changes in Crater Lake water chemistry. The unrest prompted GeoNet to raise the Aviation Colour Code although the Volcanic Alert Level remained at 1 (some signs of volcano unrest).

Source: New Zealand GeoNet Project


17 September-23 September 2008

On 18 September, GeoNet reported that the temperature of Ruapehu's summit crater lake had increased to 22.5 degrees Celsius, up from 16 degrees Celsius in August. Levels of sulfur dioxide and carbon dioxide also increased. Tremor was detected. GeoNet stated that the cyclic nature of the crater lake temperature and gas flux from Ruapehu was common; the Volcano Alert Level remained at 1 (some signs of volcano unrest).

Source: New Zealand GeoNet Project


10 October-16 October 2007

The Alert Level at Ruapehu was lowered to 1 (on a scale of 0-5) on 9 October because no further eruptions have occurred since the activity on 25 September.

Source: New Zealand GeoNet Project


19 September-25 September 2007

An eruption of Ruapehu that occurred on 25 September prompted GeoNet to raise the Alert level to 2 (on a scale of 0-5). Pilots reported that an eruption plume rose to an altitude below 4.6 km (15,000 ft) a.s.l. Further reports from ski field operators and the Eastern Ruapehu Lahar Alarm and Warning System (ERLAWS) indicated that lahars traveled down the Whakapapa ski field and possibly E in the Whangaehu river valley, and other areas.

On 26 September, aerial observations revealed that the summit area was covered with ash and mud, mostly directed N and reached 2 km from the crater lake. Impact craters caused by falling blocks over 1 m in diameter were also evident.

According to news articles, the eruption prompted evacuations at several ski lodges and caused train service to be temporarily suspended. A boulder crashed through the roof of a hut and injured one person.

Sources: New Zealand GeoNet Project, Agence France-Presse (AFP)


14 March-20 March 2007

According to news articles, a "moderate" lahar from Ruapehu's crater lake traveled E down the Whangaehu River valley on 18 March and reached the sea 140 km away after a soft rock-and-ash dam was breached. The section of dam that failed was about 40 m long and 7 m high. There were no reports of injuries or major damage to infrastructure and only some flooding to farmlands at the base of the volcano. The volume of water and debris was estimated at 1.3 million cubic meters. On 19 March, IGNS confirmed a 6-m drop in the crater lake level and reported an increase in seismicity following the lahar.

Sources: New Zealand GeoNet Project, Associated Press, Stuff, New Zealand Herald


4 October-10 October 2006

A M 2.8 earthquake centered at Ruapehu was recorded on 4 October. Scientists visited the summit crater lake on 7 October and confirmed that a small hydrothermal eruption had occurred. The lake water level had risen 1 m since a previous measurement, and evidence suggested wave action up to 4-5 m above the surface of the lake. The lake temperature was 22.5°C, up from 15°C. Ruapehu remained at Volcanic Alert Level 1 (some signs of volcano unrest).

Source: New Zealand GeoNet Project


17 November-23 November 2004

IGNS reported that a new heating cycle may be under way at Ruapehu volcano. The temperature of Crater Lake has increased three degrees to 18 degrees Celsius, and elevated levels of volcanic tremor have occurred over the last three weeks. Ruapehu remained at Volcanic Alert Level 1 (some signs of volcano unrest).

Source: New Zealand GeoNet Project


10 November-16 November 2004

Elevated levels of volcanic tremor continue at Ruapehu and may signal the start of another Crater Lake heating cycle. The Volcanic Alert Level remained at 1 (some signs of volcano unrest).

Source: New Zealand GeoNet Project


3 November-9 November 2004

On 2 November, volcanic tremor at Ruapehu increased to the highest level recorded for at least 12 months. The tremor was at moderate levels, but appeared to be declining slowly. The Volcanic Alert Level remained at 1 (some signs of volcano unrest).

Source: New Zealand GeoNet Project


4 December-10 December 2002

IGNS reported on 12 December that during the previous 2 months volcanic tremor and earthquakes had been occurring at Ruapehu, but there had been little surface change. However, during 5-12 December the temperature of Crater Lake rose 11°C, to 35°C. Ruapehu remained at Alert Level 1 (signs of volcano unrest).

Source: New Zealand GeoNet Project


9 January-15 January 2002

On 11 and 12 January steam plumes were emitted from Ruapehu. This activity was believed to be associated with hydrothermal activity in the crater lake. Prior to the steam emissions, measurements taken on 8 December revealed that the lake water temperature was at 36-38°C and that it had been heating since late November 2001. Evidence of convection was observed at the S-central vent area including minor sulfur slicks, upwelling, and light steaming. Only minor volcanic tremor was recorded at Ruapehu. The volcano remained at Alert Level 1 ("Initial signs of possible volcano unrest.").

Source: New Zealand GeoNet Project


28 November-4 December 2001

Seismicity returned to normal levels on 25 November after a moderate-to-large volcanic earthquake occurred at Ruapehu on 21 November. Observations on 25 November revealed no signs of eruptive activity. Scientists found that upwelling sediment in Ruapehu's crater lake caused the lake to change from its normal blue-green color to dark gray. In addition, the temperature of the lake was relatively low (22°C in comparison to 21°C in September), which further supported the theory that no eruptive activity occurred after the earthquake. The volcano remained at Alert Level 1 (on a scale of 0-5).

Source: New Zealand GeoNet Project


21 November-27 November 2001

On 21 November at 0218 a moderate-to-large volcanic earthquake was recorded at Ruapehu. The earthquake was followed by ~1 hour of moderate-to-strong volcanic tremor. IGNS did not believe an eruption accompanied the earthquake because no air waves were recorded and there were no reports of unusual activity. As of 23 November, seismicity continued to be higher than normal. Ruapehu remained at Alert Level 1 (on a scale of 0-5).

Source: New Zealand GeoNet Project


21 February-27 February 2001

The IGNS reported that an episode of strong volcanic tremor was recorded at Ruapehu. The tremor episode peaked on 16 February and was the strongest tremor recorded since the 1996 eruptions, but direct observations of the crater revealed a lack of unusual activity. By approximately 23 February the tremor had declined to background levels. The volcano remained at Alert Level 1.

Source: New Zealand GeoNet Project


Summary of eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2007 Sep 25 2007 Sep 25 Confirmed 1 Historical Observations
2006 Oct 4 2006 Oct 4 Confirmed 1 Historical Observations
1997 Oct 9 1997 Oct 18 Confirmed 1 Historical Observations
1996 Jun 16 1996 Sep 1 Confirmed 3 Historical Observations
[ 1996 Mar 21 (in or before) ] [ Unknown ] Uncertain 0  
1995 Jan 11 (?) 1995 Nov 9 Confirmed 3 Historical Observations
[ 1994 Feb 12 ] [ 1994 Apr 1 ] Uncertain 1  
1992 Feb 8 1992 Mar 6 Confirmed 1 Historical Observations
1991 Jul 5 (?) 1991 Jul 14 (?) Confirmed 1 Historical Observations
1990 Jun 17 1990 Sep 8 (in or before) Confirmed 0 Historical Observations
1990 Jan 7 1990 Jan 26 Confirmed 1 Historical Observations
1989 Jul 1 1989 Sep 20 (?) Confirmed 1 Historical Observations
1988 Dec 8 1989 Mar 5 (?) Confirmed 1 Historical Observations
1988 Mar 20 1988 May 25 ± 3 days Confirmed 1 Historical Observations
1987 Aug 24 1987 Aug 30 Confirmed 1 Historical Observations
1986 Feb 8 1986 Feb 9 (?) Confirmed 1 Historical Observations
1985 Nov 15 1985 Nov 15 Confirmed 1 Historical Observations
1985 May 21 (in or before) 1985 Jun 9 (?) Confirmed 1 Historical Observations
1984 Oct 25 (?) 1984 Dec Confirmed 1 Historical Observations
1984 Apr 2 Unknown Confirmed 1 Historical Observations
1981 Oct 25 (?) 1982 Apr 12 ± 3 days Confirmed 1 Historical Observations
1980 Oct 18 1980 Nov 3 Confirmed 1 Historical Observations
1980 Jan 15 (?) 1980 Mar 27 (?) Confirmed 1 Historical Observations
1979 Jun 30 1979 Jul 15 Confirmed 1 Historical Observations
1977 Jul 16 1979 Jan 17 Confirmed 2 Historical Observations
1976 Sep 12 (in or before) 1976 Nov 22 (?) Confirmed 1 Historical Observations
1976 Mar 6 1976 Mar 6 Confirmed 1 Historical Observations
1975 Oct 17 (in or before) 1975 Oct 17 (in or before) Confirmed 1 Historical Observations
1975 Apr 24 1975 Apr 27 Confirmed 2 Historical Observations
1973 Oct 31 1974 Oct 25 Confirmed 1 Historical Observations
1972 Oct 22 1973 Jan 10 Confirmed 1 Historical Observations
1971 Apr 3 1971 Nov 1 Confirmed 2 Historical Observations
1970 Sep 16 1970 Sep 17 Confirmed 1 Historical Observations
1969 Jun 22 1969 Jun 23 Confirmed 2 Historical Observations
1968 Apr 6 1968 Jun 10 Confirmed 2 Historical Observations
1967 Jul 22 1967 Oct 4 (?) Confirmed 1 Historical Observations
1966 Apr 4 1966 Sep 27 Confirmed 1 Historical Observations
1959 May 21 1959 Aug 31 Confirmed 1 Historical Observations
1956 Nov 18 1956 Nov 18 Confirmed 1 Historical Observations
1952 Jul Unknown Confirmed 1 Historical Observations
1951 Mar 19 Unknown Confirmed 1 Historical Observations
1950 Jun 26 1950 Jun 26 Confirmed 1 Historical Observations
1948 May 1 Unknown Confirmed 1 Historical Observations
1946 Nov 21 1947 May 31 Confirmed 1 Historical Observations
1946 Apr 1946 Jun Confirmed 2 Historical Observations
1945 Mar 8 1945 Dec Confirmed 3 Historical Observations
1944 Oct Unknown Confirmed 2 Historical Observations
1942 Aug 10 Unknown Confirmed 2 Historical Observations
1940 Apr Unknown Confirmed 2 Historical Observations
1936 May 9 (?) 1936 May 13 Confirmed 2 Historical Observations
1934 Dec 1935 Feb Confirmed 2 Historical Observations
1934 Aug 11 Unknown Confirmed 2 Historical Observations
1925 Jan 22 Unknown Confirmed 2 Historical Observations
1921 Oct Unknown Confirmed 2 Historical Observations
1918 Jun 29 Unknown Confirmed 2 Historical Observations
1906 Mar 15 Unknown Confirmed 2 Historical Observations
1903 Unknown Confirmed 2 Historical Observations
1895 Mar 10 1895 Mar 14 (in or after) Confirmed 2 Historical Observations
1889 May 1 Unknown Confirmed 2 Historical Observations
1861 May 16 Unknown Confirmed 2 Historical Observations
1210 ± 150 years Unknown Confirmed 3 Radiocarbon (uncorrected) Tf5 tephra
5550 BCE ± 1000 years Unknown Confirmed   Tephrochronology NE flank (Whakapapa)
7590 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected) North flank (Whakapapanui Gorge area)
7840 BCE (in or before) Unknown Confirmed 4 Radiocarbon (uncorrected) Upper north flank (Pinnacle Ridge)
9650 BCE (?) Unknown Confirmed   Tephrochronology UT2 tephra
9850 BCE (?) Unknown Confirmed   Radiocarbon (corrected) UT1 tephra

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Cameron E, Gamble J, Price R, Smith I, McIntosh W, Gardner M, 2010. The petrology, geochronology and geochemistry of Hauhungatai volcano, Taupo Volcanic Zone. J Volc Geotherm Res, 190: 179-191.

Cole J W, Graham I J, Hackett W R, Houghton B F, 1986. Volcanology and petrology of the Quaternary composite volcanoes of the Tongariro volcanic centre, Taupo volcanic zone. Roy Soc New Zeal Bull, 23: 224-250.

Cronin S J, Neall V E, Lecointre J A, Palmer A S, 1997. Changes in Whangaehu river lahar characteristics during the 1995 eruption sequence, Ruapehu volcano, New Zealand. J Volc Geotherm Res, 76: 47-61.

Cronin S J, Neall V E, Stewart R B, Palmer A S, 1996. A multiple-parameter approach to andesitic tephra correlation, Ruapehu volcano, New Zealand. J Volc Geotherm Res, 72: 199-215.

Donoghue S L, Gamble J A, Palmer A S, Stewart R B, 1995. Magma mixing in an andesite pyroclastic flow of the Pourahu Member, Ruapehu volcano, New Zealand. J Volc Geotherm Res, 68: 177-191.

Donoghue S L, Neall V E, Palmer A S, Stewart R B, 1997. The volcanic history of Ruapehu during the past 2 millenia based on the record of Tufa Trig tephras. Bull Volc, 59: 136-146.

Donoghue S, Palmer A S, McClelland E, Hobson K, Stewart R B, Neall V E, Lecointre J, Price R, 1999. The Taurewa eruptive episode: evidence for climactic eruptions at Ruapehu volcano, New Zealand. Bull Volc, 61: 223-240.

Gamble J A, Price R C, Smith I E M, McIntosh W C, Dunbar N W, 2003. 40Ar/39Ar geochronology of magmatic activity, magma flux and hazards at Ruapehu volcano, Taupo Volcanic Zone, New Zealand. J Volc Geotherm Res, 120: 271-287.

Graettinger A H, Manville V, Briggs R M, 2010. Depositional record of historic lahars in the upper Whangaeuhu Valley, Mt. Ruapehu, New Zealand: implications for trigger mechanisms, flow dynamics and lahar hazards. Bull Volc, 72: 279-296.

Graham I J, Hackett W R, 1987. Petrology of calc-alkaline lavas from Ruapehu volcano and related vents, Taupo Volcanic Zone, New Zealand. J Petr, 28: 531-567.

Green J, Short N M, 1971. Volcanic Landforms and Surface Features: a Photographic Atlas and Glossary. New York: Springer-Verlag, 519 p.

Gregg D R, 1960. Volcanoes of Tongariro National Park. New Zeal Geol Soc Handbook Inf Ser, 28: 1-82.

Hackett W R, Houghton B F, 1986. Active composite volcanoes of Taupo volcanic zone (Tour Guide C4). New Zeal Geol Surv Rec, 11: 61-114.

Hackett W R, Houghton B F, 1989. A facies model for a Quaternary andesitic composite volcano: Ruapehu, New Zealand. Bull Volc, 51: 51-68.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Jolly A D, Sherburn S, Jousset P, Kilgour G, 2010. Eruption source processes derived from seismic and acoustic observations of the 25 September 2007 Ruapehu eruption - North Island, New Zealand. J Volc Geotherm Res, 191: 33-45.

Kilgour G, Manville V, Della Pasqua F, Graettinger A, Hodgson K A, Jolly G E, 2010. The 25 September 2007 eruption of Mount Ruapehu, New Zealand: directed ballistics, surtseyan jets, and ice-slurry lahars. J Volc Geotherm Res, 191: 1-14.

Manville V, Hodgson K A, Houghton B F, Keys J R, White J D L, 2000. Tephra, snow and water: complex sedimentary responses at an active snow-capped stratovolcano, Ruapehu, New Zealand. Bull Volc, 62: 278-293.

McClelland E, Erwin P S, 2003. Was a dacite dome implicated in the 9,500 b.p. collapse of Mt Ruapehu? A palaeomagnetic investigation. Bull Volc, 65: 294-305.

Nairn I A, Cole J W, 1975. New Zealand. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 22: 1-156.

Nakagawa M, Wada K, Thordarson T, Wood C P, Gamble J A, 1999. Petrologic investigations of the 1995 and 1996 eruptions of Ruapehu volcano, New Zealand: formation of discrete and small magma pockets and their intermittent discharge. Bull Volc, 61: 15-31.

Smith G A, Grubensky M J, Geissman J W, 1999. Nature and origin of cone-forming volcanic breccias in the Te Herenga Formation, Ruapehu, New Zealand. Bull Volc, 61: 64-82.

Takano B, Ohsawa S, Glover R B, 1994. Surveillance of Ruapehu crater lake, New Zealand, by aqueous polythionates. J Volc Geotherm Res, 60: 29-57.

Ruapehu, one of New Zealand's most active volcanoes, is a complex stratovolcano constructed during at least 4 cone-building episodes dating back to about 200,000 years ago. The 110 cu km dominantly andesitic volcanic massif is elongated in a NNE-SSW direction and is surrounded by another 100 cu km ring plain of volcaniclastic debris, including the Murimoto debris-avalanche deposit on the NW flank. A series of subplinian eruptions took place at Ruapehu between about 22,600 and 10,000 years ago, but pyroclastic flows have been infrequent at Ruapehu. A single historically active vent, Crater Lake, is located in the broad summit region, but at least five other vents on the summit and flank have been active during the Holocene. Frequent mild-to-moderate explosive eruptions have occurred in historical time from the Crater Lake vent, and tephra characteristics suggest that the crater lake may have formed as early as 3000 years ago. Lahars produced by phreatic eruptions from the summit crater lake are a hazard to a ski area on the upper flanks and to lower river valleys.