Latest news & updates from White Island
White Island volcano (New Zealand): spiny lava dome observed, alert level raised
Wednesday Dec 12, 2012 10:59 AM | BY: T
GNS Science volcanologists have discovered a spiny lava dome at White Island volcano in an existing small crater formed as a result of the recent eruptions in August.
A close up view of the dome. The dome is made of thick, relatively cool and congealed lava and has prominent spines. The dome is about 20 – 30 metres across. In the foregrouond is a small, cold lake. (image: GNS)
"On Monday we were able to see a spiny lava dome that has grown in a crater formed by an eruption on August 5. We were really lucky the steam was not too thick and got great views. The dome is probably 20 – 30 metres across and has spines sticking up. In more than 30 years visiting White Island I’ve never seen anything like it," said GNS Science volcanologist Brad Scott.
"If you imagine a volcano is like a tube of toothpaste then a lava dome is like the congealed, dried toothpaste that has come out of the tube. It doesn’t move like a lava flow but grows from the inside as new magma comes up and pushes the already cooled magma upwards and outwards," said Mr Scott.
Comments from tour operators at White Island suggest the dome may have been visible for two weeks, but not as clearly as Monday. How long the dome has been growing is unknown, but possibly since the ash eruption in early August.
Lava domes are usually formed by magma that has lost most of its gases so that it is very sticky. This causes the magma to pile up over the volcanic event and form a dome. Lava domes are common at some volcanoes, but have never been seen before at White Island.
“Our concern is that lava dome growth can be accompanied by explosive eruptions and could impact people on the island. We need to see if the dome is continuing to grow. If it’s not growing then we will be less concerned,” said GNS Science head volcanologist Gill Jolly.
GNS Science continues to closely monitor White Island through the GeoNet project.
Links / Sources:
Links / Sources:
- piny lava dome – a new and unusual style of eruptive activity at White Island; Volcanic Alert is raised to Level 2; Aviation Colour Code changed to Orange (GeoNet)
Wednesday, Nov 07, 2012
No significant changes have occurred at White Island over the past months. ... [more]
Wednesday, Sep 12, 2012
Seismic activity at White Island remains slightly elevated. A weak tremor signal can occasionally be seen on the spectrogram. [more]
Sunday, Sep 09, 2012
Some elevated seismic activity and weak pulses of tremor are still occurring at White Island, but there have not been any recent ash emissions. [more]
Thursday, Aug 16, 2012
Activity has further decreased. Volcanic and seismic activity have remained low and only a minor steam plume is visible with no apparent ash. [more]
Monday, Aug 13, 2012
Activity has calmed down at White Island. Ash emissions have been lower than in the previous days. Gas measurements showed that all volcanic gases were at levels lower than the previous measurement on August 1. ... [more]