SCIENCE ALERT BULLETIN: WIZ V00/05
3 May 2000 (Wednesday)
1100 NZST (UT + 12hrs)
Situation update at White Island Volcano
Staff from the Institute of Geological & Nuclear Sciences (GNS) visited White Island yesterday (Tuesday, May 2) to make monitoring observations and to assess
the volcano status. The level of activity was similar to that reported last week. Minor eruptive activity continues from
MH vent. The Alert Level remains at 2. The hazard posed by the current eruptive activity continues.
On Tuesday May 2, MH vent was producing a weak gas and ash plume. The ash plume was rising to 1500 feet (500 m), while
the steam and gas plume rose to 2500-3000 feet (760-900 m) before being blown to the north north east. The plume was
visible more than 10-15 kilometres from the island. Ash emission is occurring continuously and there is no evidence that
larger blocks are being erupted from MH vent.
The seismograph at White Island has continued to record moderate to strong volcanic tremor. The level of tremor
fluctuates with time. Currently there does not appear to be a direct relationship between the intensity of the eruptive
activity observed at MH vent and the level of volcanic tremor. COSPEC measurements on Friday April 28 recorded a SO2
flux of 927 tonnes/day, down on the previous measurements, but consistent with the present activity.
The current activity is not an immediate hazard to visitors to White Island. However, past activity indicates that
significantly larger eruptions, some ejecting large rocks over the island, could occur with little or no warning. Such
larger eruptions would pose a significant hazard to anyone on the island at the time. Caution should be exercised when
visiting the island.
GNS volcanologists will continue to closely monitor activity at White Island and further updates will be issued as
necessary.
The continued minor eruptive activity, elevated seismicity and gas flux confirm the Alert Level remains at 2.
Brad Scott
Duty Volcanologist