Vanuatu Volcano Alert Bulletin n°9 - Ambae Activity (21 September 2018)


15°24’0”S 167°50’0”E Summit 4908ft (1496m)
Current Vanuatu Volcano Alert Level: Level 2

Ambae volcano is in the major unrest state. The Volcanic Alert Level is lowered to Level 2 .

Ambae volcano activity becomes stable. The current volcanic activity is consistent with Volcanic Alert Level 2. Possible imminent eruption could occur at any time in such major unrest state. The Danger Zone for life safety is now limited at 2 km radius from the active vent and areas located in the Yellow Zone (See Map below).

Observations in September 2018 confirm that the eruptive activity occurred in July until August has dropped. There is no explosions and volcanic cloud emitted are white colour, means only steam. A small scale eruption in Lake Voui has ceased.

The presence of ash that has fallen on Ambae during the eruptive phases will continue to change the behaviour of streams and creeks when it rains. The creeks and streams can produce floods and carry a lot more debris (sands, gravel and boulders). The flow path of streams and creeks could change due to the flood debris. Landslide may occur at some areas during heavy rain fall.

These observations and the analysis of seismic data confirm that the volcano activity is in the major unrest state. The volcano activity consist of ongoing emission of steam and/or volcanic gases. The local population and visitors can smell the volcanic gas while approaching the volcano.

Significant impact of ashes and gases emission to villages at Ambae started in March and July, when the Volcanic Alert level was raised to Level 3. Observations of the current activity are consistent with the Alert Level 2 activity. Level 2 indicates ‘Major unrest; Danger is now at 2 km around the volcanic vents and areas inside the Yellow Zone’ . The possibility that the Ambae volcano activity escalate to the level of minor eruption is now low .

Ambae volcano is a very large volcano and is frequently active. A large-scale eruption about 400 years ago built a volcanic cone in the summit crater and the crater is now filled by Lake Voui; the modern active vent area underlies Lake Voui. Historic activity is poorly known, but there is documented activity in 1530, 1670, 1870, 1915 and 1966. All documented activity has been from the summit crater (Lake Voui) except for the 1670 activity, which included a flank eruption producing lava flows at Ndui Ndui. The current eruption episode started in 1991, with eruptions in 1995, 2005, 2016 and 2017. The current eruption is focused in the summit crater and there are no indications of activity elsewhere on Ambae Island for now.

Advise to all tourism agencies, local authorities, people of Ambae and the general public not to access the Danger Zone which is now about 2 km radius from the eruptive vent. Volcanic gases are expected in this area. Villages in the Yellow Colour may continue to expect change in streams and creeks flows during rain fall (See map below). Villages from Ambae island may experience impacts of volcanic gases especially those exposed to prevailing trade winds direction and others hazards related to the volcanic activity may be expected. For more information about reducing risks of the above (gases), please see Volcano Key Messages at the link below: .

The Vanuatu Meteorology and Geohazards Department will continue to closely monitor this volcano activity. More information will be provided as available.

For further information, please contact Geohazards Division at the Vanuatu Meteorology and Geohazards Department at or 24686 .