Vanuatu

Vanuatu Volcano Alert Bulletin n°6 - Ambae Activity (May 27th 2021)

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Situation Report
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AMBAE VOLCANO
15°24’0”S 167°50’0”E Summit 4908ft (1496m)
Current Vanuatu Volcano Alert Level: Level 1

Volcanic activity at Ambae is continuing in the level of minor unrest. The Volcanic Alert Level remains at Level 1

The Ambae volcanic activity decreased in the low level of minor unrest and is consistent with the Volcanic Alert Level 1. Latest observation images captured by the monitoring webcam shows no steam cloud emission as observed on the 04th and 05th May 2021 from the eruptive vent inside the lake Voui.

The danger zone for life safety at the summit area remains limited in the Danger Zone A (See Ambae caldera safety map below). This danger zone (Danger Zone A) is about 2 km radius from the 2017-2018 active vents. An additional danger zone is within areas of flowing creeks during heavy rain (e.g. remobilization of remaining ash from 2017 and 2018 eruption).

Latest observations and analysis of the Ambae seismic data from the volcano monitoring system confirmed the decrease of Ambae volcanic activity in the minor unrest level (Level 1). There is no obvious emission of volcanic steam or gases from the eruptive vent(s) of Lake Voui (like on the 4th and 5th May 2021).

The Volcanic Alert Level (VAL) for Ambae has been at Level 1 since 23rd September 2019. Observations of the current activity are consistent with the activity of the Volcanic Alert Level 1. Level 1 indicates ‘Minor level of unrest; Danger area remains at 2 km around the volcanic vents and within the area of flowing creeks. **With this current volcanic activity, it is a useful reminder that eruptions can occur at any level of unrest with little or no warning.

**

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 that crater is now filled by Lake Voui; however, the modern active vent area is now within the volcanic cone that grew in 2017-2018. 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 2017-2018 eruption episode started in 1991, with eruptions in 1995, 2005, and 2016 leading to the 2017-2018 activity.

All tourism agencies, local authorities, people of Ambae and the general public are reminded that with the current volcano activity, the danger zone (Danger Zone A) remains at the summit about 2 km radius from the 2017-2018 active vent. In addition, the presence of remaining volcanic ashes elsewhere in the island (deposited during the 2017/18 eruption), can be mobilized by rainfall. The villages located near flowing creeks (dangerous flow zones) can continually expect changes in stream behaviour and larger than normal flow rates during heavy rains. People of Ambae Island need to beware of the dangerous flows while approaching these creeks during heavy rains.
More information about the volcanic hazards can be found on the website:
https://www.vmgd.gov.vu/vmgd/index.php/geohazards/volcano/volcano-info/resources

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