Eruption inside Benbow crater, Alert Level for Ambrym volcano raised to 3, Vanuatu

The Ambrym volcano in Vanuatu has transitioned from minor unrest to a minor eruption state over the weekend, leading authorities to raise the Volcanic Alert Level from 1 to 3 on January 14, 2024. The eruption occurs inside the Benbow crater, with a designated Danger Zone B extending approximately 2 km (1.2 miles) around Benbow and 4 km (2.4 miles) around Marum craters.

Activity at Ambrym volcano in Vanuatu has intensified over the last 2 days, progressing from a state of minor unrest to a minor eruption. As a result, the Volcanic Alert Level has been elevated from Level 1 to Level 3.

The eruption is currently active within the Benbow crater, and authorities have delineated Danger Zone B, which extends about 2 km (1.2 miles) around Benbow and 4 km (2.4 miles) around Marum craters, including Maben-Mbwelesu, Niri-Mbwelesu, and Mbwelesu.

Additionally, a hazard zone extends 500 m (1 640 feet) from major cracks to the southeast of Ambrym, which opened during the 2018 eruption.

Observations made using webcam and seismic data analysis on January 13, 2024, confirmed the eruption started at 11:17 UTC. The volcanic activity is characterized by a strong glow, loud explosions, and the emission of gas and steam.

Residents of Ambrym and neighboring islands may witness gas plumes and observe volcanic glow.

The Alert Level for Ambrym volcano has been at Level 1 since October 10, 2019. The current eruption, classified as a small-scale event, aligns with the characteristics of Alert Level 3. This level indicates a ‘Minor eruption’. Presently, the likelihood of the volcanic activity escalating to a moderate eruption (Level 4) is considered low.

Ambrym volcano, a highly active volcano in Vanuatu, features a large 12 km (7.5 miles) diameter caldera with two active craters, Marum and Benbow.

Historically, the volcano has produced moderate explosive eruptions and lava flows reaching the coast, with significant events in 1820, 1894, 1913, and 1929.

Over the past seventy years, prior to the 2018 eruption, there were no eruptions beyond the summit caldera. The 1988 and 2015 eruptions were focused within the caldera, while the December 2018 eruption, primarily in the summit caldera, also affected the Eastern Fracture Zone with ground deformation and faulting, but without eruptive activity. Recent episodes of unrest include events in October 2021 at Marum crater and January 2022 at Benbow crater, both resulting in lava flows within the active craters.

References:

¹ VANUATU VOLCANO ALERT BULLETIN N°1 – AMBRYM ACTIVITY – VMGD – January 14, 2024

Featured image credit: VMGD