Shreve T. auteur aut IRD Grandin R. auteur aut IRD Boichu M. auteur aut IRD Garaebiti E. auteur aut IRD Moussallam Yves auteur aut IRD Ballu V. auteur aut IRD Delgado F. auteur aut IRD Leclerc F. auteur aut IRD Vallée Martin auteur aut IRD Henriot N. auteur aut IRD Cevuard S. auteur aut IRD Tari D. auteur aut IRD Lebellegard Pierre auteur aut IRD Pelletier Bernard auteur aut IRD text journalArticle eng text/pdf reformatted digital access Eruptive activity shapes volcanic edifices. The formation of broad caldera depressions is often associated with major collapse events, emplacing conspicuous pyroclastic deposits. However, caldera subsidence may also proceed silently by magma withdrawal at depth, more difficult to detect. Ambrym, a basaltic volcanic island, hosts a 12-km wide caldera and several intensely-degassing lava lakes confined to intra-caldera cones. Using satellite remote sensing of deformation, gas emissions and thermal anomalies, combined with seismicity and ground observations, we show that in December 2018 an intra-caldera eruption at Ambrym preceded normal faulting with >2 m of associated uplift along the eastern rift zone and 2.5 m of caldera-wide subsidence. Deformation was caused by lateral migration of >0.4 cubic kilometers of magma into the rift zone, extinguishing the lava lakes, and feeding a submarine eruption in the rift edge. Recurring rifting episodes, favored by stress induced by the D'Entrecasteaux Ridge collision against the New Hebrides arc, lead to progressive subsidence of Ambrym's caldera and concurrent draining of the lava lakes. Although counterintuitive, convergent margin systems can induce rift zone volcanism and subsequent caldera subsidence. specialized VANUATU AMBRYM ILE 066 064 9 art. 18868 [13 p.] 2019 2045-2322 https://www.documentation.ird.fr/hor/fdi:010077480 10.1038/s41598-019-55141-7 2045-2322 [F B010077480] https://www.documentation.ird.fr/hor/fdi:010077480 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers20-01/010077480.pdf IRD - Base Horizon / Pleins textes 2020-02-05 2025-02-24 fdi:010077480 fre