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Ruapehu: warning of ‘elevated unrest’ 14 May 2008

Posted by admin in activity reports, New Zealand, Ruapehu.
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In a bulletin issued yesterday, 13 May 2008, New Zealand’s geohazards monitoring organization GeoNet warns that ‘Elevated gas output, high lake temperatures and volcanic tremor continue to indicate elevated unrest at Ruapehu’.

CO2 and SO2 levels in Ruapehu’s gas plume are both significantly above normal background levels, and a slight increase in the levels of volcanic tremor has continued, with some periods of stronger tremor. The temperature of Crater Lake remains elevated, fluctuating between 34°C and 36.8°C:

Sustained heat from depth is required to keep the temperature this high for this length of time. It is believed that the source of this heat is magma within the volcano conduit. This magma is also producing the higher than normal gas flow and chemical changes. … These observations are consistent with the volcano-hydrothermal system responding to recent eruptions and ongoing interaction with magma in the volcano conduit. The volcano remains in a status of unrest and the possibility of further activity remains at the volcano. If further eruptions occur, they may occur without warning.

The New Zealand Herald quotes GNS Science volcanologist Dr Tony Hurst as saying that on the basis of these signs Ruapehu ‘was not likely to erupt this year, but the signs did point to an increased risk of volcanic activity. That could mean steam plumes, gas bubbles and fountains from Crater Lake, he said’. The Herald‘s report on Ruapehu is cheerfully categorized as a ‘natural disasters story’.

The alert level for Ruapehu remains at level 1 (departure from typical background activity, signs of unrest).

For all our New Zealand coverage: New Zealand << The Volcanism Blog

Global Volcanism Program: Ruapehu – summary information for Ruapehu (0401-10=)
GeoNet volcanoes – volcano information from GeoNet, the organization responsible for volcano monitoring in New Zealand
GeoNet Volcano Alert bulletins – volcanic activity bulletins from GeoNet

Restless Ruapehu emits danger signs – NZ Herald, 14 May 2008
Molten rock on the move in NZ volcano – Radio Australia, 13 May 2008
Scientists warn Ruapehu emitting more gas – Stuff.co.nz, 13 May 2008

The Volcanism Blog