Revised Minoan eruption volume as benchmark for large volcanic eruptions

Area of Science:

• Volcanology
• Geophysics
• Sedimentology

Background:

• Accurate estimation of large volcanic eruption volumes is vital for understanding global societal impacts and assessing hazards.
• Previous volume estimates for major eruptions, like the Minoan event, have been poorly constrained.
• Integrated geophysical and sedimentological approaches are needed for robust volume assessments.

Purpose of the Study:

• To accurately estimate the total dense-rock equivalent (DRE) volume of the iconic Minoan eruption.
• To differentiate and quantify volumes of various deposit types, including tephra fall, ignimbrites, and intra-caldera material.
• To refine understanding of the Minoan eruption's eruptive phases and their contributions to deposit volumes.

Main Methods:

• Integration of seismic reflection and P-wave tomography datasets.
• Application of computed tomography-derived sedimentological analyses.
• Comparison of estimated eruption volumes with independent caldera collapse reconstructions.

Main Results:

• A total DRE eruption volume of 34.5 ± 6.8 km³ was determined for the Minoan eruption.
• Breakdown of volumes includes 21.4 ± 3.6 km³ tephra fall, 6.9 ± 2 km³ ignimbrites, and 6.1 ± 1.2 km³ intra-caldera deposits.
• The Plinian phase was the primary contributor to distal tephra fall, with pyroclastic flow volumes being smaller than previously estimated.

Conclusions:

• Complementary geophysical and sedimentological datasets are essential for reliable volcanic eruption volume estimates.
• Accurate volume data is critical for effective regional and global volcanic hazard assessments.
• This study provides a benchmark for future reconstructions of large-scale eruption volumes.