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Vanuatu Volcano Alert Bulletin n°13 - Ambae Activity (December 8th 2021)

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

The Volcanic activity on Ambae Island has slightly increased at the minor unrest level. The Volcanic Alert Level remains at Level 1.

The volcanic activity on Ambae has slightly increased in the minor unrest level, consistent with the Volcanic Alert Level 1. Since 5th of December 2021, the volcano activity consists of emission of steam, with an average height of approximately 250m, and explosions of wet tephra ejected above the lake surface (approximately < 10m),. New analyses suggest that the volcano activity is likely to continue at this level of minor unrest. Volcanic hazards remain at the summit area and creeks (e.g., remobilization of remaining ash from 2017 and 2018 eruption).

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.

The Volcanic Alert Level (VAL) for Ambae has remained at Level 1 since the 23rd of September 2019. Observations of the current volcanic activities are consistent with the activity of the Ambae volcano under 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 warnings.

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: http://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.

Note : « Posted sign » : Signs will be installed later at the locations shown on the above image.

For further information, please contact Geohazards Division at the Vanuatu Meteorology and Geohazards Department at geohazards@meteo.gov.vu or 24686.