Internal structure of the volcanic island of Surtsey and surroundings: Constraints from a dense aeromagnetic survey

A dense aeromagnetic survey of Surtsey, a young volcanic island off Iceland's south coast, reveals that the island lacks significant basaltic intrusions within its five vents, suggesting magma fragmentation dominated submarine eruptions from the onset. The study, using 2D spectral analysis and Euler deconvolution, identified a small magnetic anomaly over the submarine edifice of Surtla, hinting at preserved dykes during weak or moderate explosive activity in 1963–1964. Additionally, a 10–20 m thick pillow lava field, extending ~1 km south of Surtsey, was detected, indicating channelized intrusive flow during early effusive eruptions in May–July 1964. The survey also found indications of magnetized volcanic rocks predating the Surtsey eruption beneath Jólnir, an ephemeral island.

Sayyadi, S., Gudmundsson, M. T., White, J. D. L., Jónsson, T., Brown, M. C., & Jackson, M. D. (2024). Internal structure of the volcanic island of Surtsey and surroundings: Constraints from a dense aeromagnetic survey. Journal of Volcanology and Geothermal Research, 451, 108096. https://doi.org/10.1016/j.jvolgeores.2024.108096