Feb 21 2001, 11:30 am - White Island Volcano

GNS volcanologists visited White Island Tuesday afternoon (February 20) to make direct visual observations. The activity experienced on Monday (February 19) was considered to be within the background range of eruptive activity currently taking place at White Island. On this basis the Scientific Alert Level remains at Level 1.

GNS volcanologists visited White Island Tuesday afternoon (February 20) (approx 2 - 5.30 pm). The weather at the time was overcast. There was a strong gas/steam plume coming from MH vent. There was no ash present in the plume which extended to approx. 770 m (2500 feet) and was being blown south-south west by a light wind. The plume quickly disappeared into the low cloud. The lake was light green colour with minor slicks and minor convection in 2 or 3 places. The lake has completely drowned the July 27, 2000 vent and surrounding area so that MH vent is the only major source of gas/steam visible. The steam/gas flux from MH appeared quite vigorous and was audible. There has been a lot of erosion and re-deposition of sediments from the walls of Main Crater onto the floor. Impact craters caused by ballistic ejecta were observed adjacent MH vent. These craters were modified by rainfall and are not considered associated with Monday's phase of ash emission. A thin veneer of ash from Monday's brief eruptive episode was observed extending over the south-west quadrant of White Island.

Robert Fleming (White Island helicopter tour operator) reported (in addition to the ash emission) that on Monday the lake was grey and convecting vigorously near MH vent. By Tuesday morning the lake was green and convecting only slightly.

The activity experienced on Monday (February 19) is within the background range of eruptive activity currently taking place at White Island. On this basis the Scientific Alert Level remains at Level 1.

Brent Alloway
Duty Volcanologist