Ruapehu volcano (North Island, New Zealand): new heating phase starts at the crater lake

Fri, 16 Jul 2021, 06:14

06:14 AM | BY: MARTIN

Ruapehu volcano today (image: GeoNet)

Typically, over periods of months, Ruapehu's crater lake (Te Wai ā-moe) experiences heating and cooling cycles. In late December 2020 the lake heated to around 43°C marking the high point of the previous cycle. Early 2021 the lake cooled through to February 2021, before starting to heat again in early March. A maximum of 41°C was reached on 12 April 2021. The lake then started to cool down to 20°C on 2 July. The lake temperature started to rise again last week and is currently 23°C.
While the lake was cooling (April-July) the modelled heat input into the lake was around 80-100 MW (megawatt). To heat the lake water temperature by 3°C modelling indicates that ~300-600 MW (megawatt) of heat is now entering the lake.
Two small earthquakes have been located, and higher level of volcanic tremor has accompanied the start of the increase in the lake temperature. The occurrence of tremor is quite typical of the start of such heating phase.
Routine monitoring at the volcano includes gas measurement flights and crater lake (Te Wai ā-moe) water samplings. The results from these visits and of continuous monitoring of volcanic earthquake activity, tremor levels, and crater lake (Te Wai ā-moe) temperature and water level indicate that key monitoring parameters remain within normal ranges. The lake is currently overflowing into the Whangaehu river.
The Volcanic Alert Level remains at Level 1 and the Aviation Colour Code remains at Green.
Source: GeoNet New Zealand volcano activity update 16 July 2021

All news about: Ruapehu volcano
Information about: Ruapehu volcano

Previous news

Tue, 8 Jun 2021, 20:09

Ruapehu volcano (North Island, New Zealand): Crater Lake temperature down to 26°C

Ruapehu volcano’s Crater Lake (image: GeoNet)

The activity of the volcano continued at fluctuacting levels as in December last year the elevated volcanic activity was recorded, but this unrest decreased on 11 January 2021. ... Read all

Wed, 13 Jan 2021, 06:00

Ruapehu volcano (North Island, New Zealand) - Smithsonian / USGS Weekly Volcanic Activity Report for 13 January-19 January 2021 (Continuing Activity)

GeoNet reported that volcanic tremor at Ruapehu declined to low levels on 29 December 2020, and remained low; volcanic gas emissions returned to background levels by the next day. Water chemistry had only slightly changed compared to data collected a few weeks prior. Although the temperature of the crater lake water remained high (40 degrees Celsius), the period of heightened unrest was over; the Volcanic Alert Level was lowered to 1 and the Aviation Color Code was lowered to Green on 11 January. ... Read all

Mon, 11 Jan 2021, 11:46

Ruapehu volcano (North Island, New Zealand): Volcanic Alert Level lowered to Level 1; activity has decreased

Aerial view of Crater Lake at Ruapehu volcano (image: GeoNet)

The activity of the volcano continues at fluctuating levels during the past few months and currently continues at low levels. ... Read all

Mon, 28 Dec 2020, 08:27

Ruapehu volcano (North Island, New Zealand): crater lake temperature has decreased

Satellite imagery of Ruapehu volcano (image: Sentinel 2)

GeoNet reported that the crater lake temperature has decreased since the last update. On 21 December the temperature reached a maximum of 43 °C that subsequently declined to approx. 41 °C. A lake temperature peak of approximately 40-46 °C is common during the heating-cooling cycles. The lake temperature exceeded 40 °C on at least 7 occasions since 2007. According to lake temperature decrease, estimated energy into the crater lake has decreased from 400 MW to 200 MW. ... Read all

Wed, 23 Dec 2020, 06:00

Ruapehu volcano (North Island, New Zealand) - Smithsonian / USGS Weekly Volcanic Activity Report for 23 December-29 December 2020 (New Activity / Unrest)

On 28 December GeoNet reported that during the previous week the temperature of Ruapehu's crater lake water slightly decreased from 43 to 41 degrees Celsius. Moderate-to-strong levels of volcanic tremor were recorded along with a small number of shallow volcanic earthquakes. The largest volcanic earthquake was an M 2.2 (on 26 December) which was uncommonly large, and combined with elevated tremor indicated ongoing unrest. ... Read all

Tue, 22 Dec 2020, 11:26

Ruapehu volcano (North Island, New Zealand): Volcanic Alert Level raised to Level 2; crater lake heating to over 40°C

GeoNet reported that Crater Lake (Te Wai ā-moe) temperature has been rising and is now 43ºC. During a gas flight last week, the lake was observed to be a uniform grey colour which shows it is well-mixed. The gas output through the crater lake has also increased markedly in response to this heating cycle. The amounts of carbon dioxide (CO2) and sulphur gases (SO2 and H2S) in the plume are the largest measured in the past two decades. The continued flow of gases and hydrothermal fluids though the lake shows that the underlying vent area is open. ... Read all

Wed, 16 Dec 2020, 06:00

Ruapehu volcano (North Island, New Zealand) - Smithsonian / USGS Weekly Volcanic Activity Report for 16 December-22 December 2020 (New Activity / Unrest)

GeoNet reported a warming trend of the crater lake water at Ruapehu, with a high temperature of 43 degrees Celsius. During an overflight to measure gas emissions the previous week, scientists observed that the lake was a uniform gray color (suggesting it is well mixed) and some water overflow at the lake's outlet. Gas output had increased in response to the heating cycle; the amounts of carbon dioxide (CO2) and sulfur gases (SO2 and H2S) in the plume were the largest measured in the past two decades. ... Read all

Wed, 4 Nov 2020, 09:36

Ruapehu volcano (North Island, New Zealand): crater lake temperature is rising again

Ruapehu volcano today (image: GeoNet webcam)

GeoNet reported that the activity at Crater Lake (Te Wai ā-moe) is characterized by a heating-cooling cycle. In late September the lake had cooled to around 12 °C marking the low point of the cycle. Since mid-October the lake has been warming slowly and has now reached 22 °C. ... Read all

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