alert bulletin: Jun 17 2008, 3:00 pm - White Island Volcano

Science Alert Bulletin WIZ-08/03 - Earthquake activity declines; Alert Level remains at 1

A typical aftershock sequence has followed the magnitude 5.4 earthquake that occurred on Friday June 13, 10 km south-west of White Island. There has been no significant response from the volcano. The gas flux has not changed and there has been some minor volcanic tremor, which is not uncommon at White Island. Activity appears normal for White Island, however, we cannot guarantee there will be no response at the island in the future.

The earthquake on Friday has been followed by many aftershocks (several hundreds) and the larger ones have been felt on the Bay of Plenty coast. Monitoring of the volcano since Friday has established that there has been no immediate significant response from the volcano. Starting Sunday morning, and lasting through to Monday we have recorded volcanic tremor and some volcanic earthquakes; these continue intermittently. Volcanic seismicity, including weak volcanic tremor and volcanic earthquakes, are common at White Island. Gas monitoring has not shown any change in gas flux.

White Island is an active volcano and eruptions can occur at any time without warning. As a consequence of this earthquake sequence the eruption hazard at the island may have increased above the normal levels. However as we have not recorded any significant changes over the last few days, it would appear the volcano is returning to a normal quiescent state. Normal cautions should be applied when visiting the volcano.

The Alert Level for White Island remains at Alert Level 1; there is no significant change in volcanic activity on the island.

Brad Scott
for Duty Volcanologist