Ruapehu volcano (North Island, New Zealand): new heating phase starts at the crater lake
Fri, 16 Jul 2021, 06:1406:14 AM | BY: MARTIN
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.
Ruapehu volcano today (image: GeoNet)
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
Tue, 8 Jun 2021, 20:09
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