News and activity reports about Ruapehu volcano:
Ruapehu volcano (North Island, New Zealand): Volcanic Alert Level lowered to Level 1; activity has decreased
Mon, 11 Jan 2021, 11:4611:46 AM | BY: MARTIN
The activity of the volcano continues at fluctuating levels during the past few months and currently continues at low levels.
Aerial view of Crater Lake at Ruapehu volcano (image: GeoNet)
GeoNet reported that gas emissions have declined to normal levels on 30 Dec last year.
On 29 Dec a volcanic tremor has decreased and remains at low levels.
Chemical analysis of water collected from Crater Lake (Te Wai ā-moe) on 31 Dec showed small changes in key parameters since previous observations a few weeks earlier on 2 Dec.
The temperature of water in Crater Lake (Te Wai ā-moe) reached a maximum of 43 °C on 21 Dec and in the last three weeks has declined to 40°C.
Approx. 200 MW (megawatt) of heat is still entering the lake and is expected to lag behind the high gas emissions observed in mid-December. A decline of lake temperature is expected.
The key parameters of the reduced unrest at the volcano are the low volcanic gas emission rate, the reduced level of volcanic tremors, and the small changes in lake water chemistry.
The Volcanic Alert Level is lowered to Level 1 and the Aviation Colour Code is lowered to Green.
Source: GeoNet New Zealand volcano activity update 11 January 2021
Mon, 28 Dec 2020, 08:27
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
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, 4 Nov 2020, 09:36
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
Thu, 22 Oct 2020, 07:54
GeoNet observatory reported that the activity at Crater Lake (Te Wai ā-moe) is often dominated by a heating-cooling cycle. In the most recent cycle, the lake temperature reached a high of 41°C in April and then cooled steadily to 12 °C by late September. Over the last two weeks, the lake has warmed slightly to 15 °C, which is a normal observation. ... read all
Tue, 11 Aug 2020, 08:58
GeoNet observatory reported that since April 2020, lake temperature has decreased from a high of 42°C to around 22-23 °C. This lower lake temperature is normal for Crater Lake. To keep the lake at this temperature, low-level heat must continue to flow into the lake. This indicates that the underlying vent area is open to volcanic gases and hydrothermal fluids. Other signs that point to this open vent are visible upwellings and sulphur slicks on the lake surface. ... read all