Volcanic alert level lowered at Whakaari - White Island
Monday, 1 July 2019
The Volcanic Alert Level at Whakaari - White Island has been lowered to level 1, after scientists recorded decreasing gas emissions.
The alert level at the Bay of Plenty volcano was raised to level 2 last week following moderate unrest.
Whakaari - White Island is New Zealand's most active cone volcano.
In a statement on GeoNet's website, duty volcanologist Agnes Mazot said that the threat level was lowered on Monday after tests showed there less sulphur dioxide being detected than previously.
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'The lower gas flux measured, new observations and modelling of monitoring data suggest that Whakaari/White Island is back to minor volcanic unrest. As such we have changed the Volcanic Alert Level down to 1.'.
Volcano Alert Level 2 is mostly associated with volcanic unrest hazards with potential for eruption hazards. These hazards could include; ash clouds, flying rocks and mudflows and lava flows.
Level 1 indicates minor volcanic unrest, where hazards, such as steam eruptions, earthquakes and landslides could still occur.
Mazot stated that the two additional gas flights detected 880 tons/day of sulphur dioxide on Friday June 28, and 693 tons/day on Saturday June 29 - which were much lower values than earlier measurements.
'New measurements made on the island show no change in fumarole temperature. Modelling of ground deformation monitoring data also suggest that the small signal recorded on Whakaari/White Island is likely to be related to the nearby ongoing swarm of tectonic earthquakes, and not an increase in volcanic activity.
'Nearby earthquake swarms are continuing, although at lower levels than we reported in previous bulletins.'
Further gas measurements would take place once the conditions allowed, Mazot said.
The aviation colour code remained as Yellow - which means that volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.
Last week, geothermal activity in Rotorua caused a mudpool to explode out of a resident's backyard.
In June, a swarm of small earthquakes also took place near the Bay of Plenty island. In May, a similar swarm of earthquakes occurred around Whakaari - White Island, with more than 300 earthquakes, centred 20km deep or less, recorded under the sea.
White Island last erupted in April 2016, when a minor eruption took place.