White Island volcano has not reacted significantly to Friday’s nearby earthquake, and activity noted since is thought to be normal behaviour for the volcano.
Following the very shallow magnitude 5.4 earthquake located 10 km south-west of White Island on the morning of Friday 13th June 2008, volcanologists were concerned that the nearby volcano might be disturbed by the tremor.
Earthquake activity in the area was elevated for some days, but tectonic and not volcanic in origin. Several hundred aftershocks have been recorded by instruments with the larger events being felt onshore in the Bay of Plenty area. A further two earthquakes of magnitude 3.9 and 3.7 struck 2 minutes apart this afternoon (Wednesday 18th).
The volcano itself went through a period of heightened activity starting Sunday morning, with increased volcanic tremor and some volcanic earthquakes. However the activity, which ceased on Monday, is common at White Island and was not considered significant. The activity is still continuing intermittently.
Monitoring of volcanic gases has not shown any change from typical readings.
In a media release yesterday afternoon Brad Scott, Duty Volcanologist for GNS Science reported, “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.”
The Alert Level for White Island remains at 1 (signs of unrest).
[Compiled from data provided by the GeoNet project and its sponsors EQC, GNS Science and FRST.]