Vanuatu

Vanuatu Volcano Alert Bulletin n°5 - Ambae Activity (27 May 2019)

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

Ambae volcano is continuing in the major unrest state. The Volcanic Alert Level remains at Level 2.

Ambae volcano activity remains at Level 2. Imminent eruption could occur in such major unrest state. The Danger Zone at the caldera remains at 2 km radius from the active vent. The Danger Zone for life safety remains limited at the Danger Zone A (See Safety Map below). An additional Danger Zone is located within the area of flowing creeks during heavy rain.

The volcanic ashes that fell on Ambae during the 2017 and 2018 eruption could 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.

Latest observations and analysis of seismic data recorded from the monitoring station confirm that the volcano activity is in the major unrest state (Level 2). The volcano activity consist of ongoing emission of steam and/or other volcanic gases. Villages exposed to dominant winds could expect to find volcanic ashfalls deposits and smell volcanic gases.

Alert Level for Ambae has been at the Level 2 since 21st September 2018. Observations of the current activity are consistent with the Alert Level 2 activity. Level 2 indicates "Major unrest; Danger Zone remains at 2 km radius from the volcanic cone and areas inside the Yellow Zone". The possibility that Ambae volcano activity escalate to the level of minor eruption (Level 3) and/or lowered to the lower unrest state (Level 1) is low for now.

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 eruption episode 2018 started in 1991, with eruptions in 1995, 2005, 2016 and 2017.

All tourism agencies, local authorities, people of Ambae and the general public are reminded that due to the current volcano activity, the danger zone remains at the Danger Zone A which is set about 2 km radius from the eruptive vent. Volcanic gases will always be expected in this area. Due to the presence of the volcanic ashes deposit at the summit of the island during the last eruption villages near flowing creeks (Dangerous Flows Zone) can continually expect changes in stream behavior and flow rates streams during heavy rains. villages from Ambae island may experience impacts of volcanic gases especially those exposed to prevailing trade winds direction, see the Ambae Volcano Advice Key Messages at this link:
http://www.vmgd.gov.vu/vmgd/index.php/geohazards/volcano/volcano-info/resources and others hazards related to the volcanic activity may be expected.