Ruapehu volcano (North Island, New Zealand): increased seismic activity
Tue, 3 Mar 2020, 08:1708:17 AM | BY: MARTIN
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.
Ruapehu volcano today (image: GeoNet)
The amounts of carbon dioxide (CO2) and sulphur gases (SO2 and H2S) have increased since the last measurements on 7th February 2020. Water samples are being analysed this week, with chemistry results expected by next week.
New analysis of last week's volcanic earthquakes defines a source area 3 km beneath the summit of the volcano, which is normal for seismic activity at Ruapehu. Volcanic tremor increased in strength briefly last weekend, then declined during the week, and has now increased again to similar levels.
In response to the earthquakes last week, Crater Lake (Te Wai ā-moe) has slowly heated from 24ºC and is currently at 30ºC. Upwelling of grey sediment and sulphur slicks on the lake surface were observed during the last week. The flow of gases and hydrothermal fluids though the lake show that the underlying vent area is open.
It is not unusual to observe volcanic earthquakes at Ruapehu and similar episodes of increased seismic activity and gas flux were observed during March 2018 and 2019, September 2017 and April 2016. None of these resulted in a sustained increase in volcanic unrest.
Both the Volcanic Alert Level (level 1) and Aviation Code (Green) remain unchanged.
Source: GeoNet New Zealand volcano activity update 3 March 2020
Mon, 24 Feb 2020, 07:27
Ruapehu volcano (North Island, New Zealand) activity update: seismic unrest recorded since the last update
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. ... Read all