News and activity reports about Ruapehu volcano:
Mt Ruapehu (North Island, New Zealand):increasing crater lake temperature
Friday Mar 20, 2020 05:56 AM | BY: MATTHEW
GNS Science Volcanologists have collected water samples from Crater Lake (Te Wai ā-moe) and the temperature of the lake is now 40°C. GeoNet believe the heating of the lake is the response to an input of hot gases and hydrothermal fluids in the wake of volcanic earthquakes beneath Mt Ruapehu in February. Prior to the earthquakes, the lake measured 24ºC.
In the last report, we noted that the GeoNet volcanologist reported “an upwelling of grey sediment and sulphur slicks on the lake surface.” Now the lake is well mixed and has changed to a uniform grey colour. The continued flow of gases and hydrothermal fluids through the lake show that the volcano’s vent underlying Crater Lake is open.
GeoNet report that the lake is overflowing at the outlet channel, with a notable decrease in the flow rate between their last two visits. Also, volcanic tremor increased in response to the volcanic earthquakes, peaking in early March, then declined slowly until today. Modelling of the energy input into the lake shows that the heat input increased from around 200 MW to around 600 MW but has now declined as the temperature rise has slowed. Heating cycles such as this are very common at Ruapehu.
The amounts of carbon dioxide (CO2) and sulphur gases (SO2 and H2S) in the atmosphere above the volcano measured on 28 February was greater than when measured on 7 February. However, the recent values are not unusual and are within the ranges measured over the past year.
The Volcanic Alert Level remains at Level 1. The Volcanic Alert Level reflects the current level of volcanic activity and is not a forecast of future activity. Mt Ruapehu is an active volcano and has the potential to erupt with little or no warning when in a state of volcanic unrest. There is no change in the Aviation Colour Code from Green.
Links / Sources:
Links / Sources:
Tuesday, Mar 03, 2020
GeoNet volcanologists have collected water samples from Crater Lake and measured volcanic gases in the plume last week. Seismic data have been analysed in detail. ... [more]
Ruapehu volcano (North Island, New Zealand) activity update: seismic unrest recorded since the last update
Monday, Feb 24, 2020
GeoNet reported that seismographs detected a sequence of seismic events beneath Mt Ruapehu during 22-23 February. GNS Science volcanologists have categorised them as volcanic earthquakes. The larger events at the start of the episode are approximately magnitude 1.5 and later, smaller events are too small to be located by GeoNet’s earthquake detection-location system. ... [more]
Wednesday, Jan 15, 2020
GeoNet reported that the activity of volcanic tremor continues at low levels. Measurements of the volcano’s Crater Lake (Te Wai ā-moe) temperature, and chemistry remained consistent in combination with seismic unrest. ... [more]
Wednesday, Apr 17, 2019
Another phase of increased crater lake temperatures has been recorded at the Te Wai ā-moe (Crater Lake) Mt Ruapehu in combination with moderate levels of volcanic tremor. ... [more]
Monday, Nov 07, 2016
Volcanic tremor (which is normally present at the volcano) has increased a notch since mid October, but not enough to trigger a raise in alert status of the volcano (which remains at level 1). New Zealand's GNS Science issued a note but does not expect the volcano to erupt soon. ... [more]