High-resolution ice-core analyses identify the Eldgjá eruption and a cluster of Icelandic and trans-continental tephras between 936 and 943 CE.

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Hutchison, W., Gabriel, Imogen, Plunkett, G., Burke, A., Sugden, P., Innes, H., Davies, S., Moreland, W., Krüger, K., Wilson, R., Vinther, B. M., Dahl-Jensen, D., Freitag, J., Oppenheimer, C., Chellman, N., Sigl, Michael, McConnell, J. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2024
• Subjects: 530 Physics; 540 Chemistry; 550 Earth sciences & geology; Greenland; Eldgjá; Veiðivötn; Greenland ice cores; ice core; Iceland
• Online Access: https://boris.unibe.ch/199919/1/JGR_Atmospheres_-_2024_-_Hutchison_-_High_Resolution_Ice_Core_Analyses_Identify_the_Eldgj__Eruption_and_a_Cluster_of.pdf; https://boris.unibe.ch/199919/

The Eldgjá eruption is the largest basalt lava flood of the Common Era. It has been linked to amajor ice‐core sulfur (S) spike in 939–940 CE and Northern Hemisphere summer cooling in 940 CE. Despite itsmagnitude and potential climate impacts, uncertainties remain concerning the eruption timeline, atmosphericdispersal of emitted volatiles, and coincident volcanism in Iceland and elsewhere. Here, we present acomprehensive analysis of Greenland ice‐cores from 936 to 943 CE, revealing a complex volatile record andcryptotephra with numerous geochemical populations. Transitional alkali basalt tephra matching Eldgjá arefound in 939–940 CE, while tholeiitic basalt shards present in 936/937 CE and 940/941 CE are compatible withcontemporaneous Icelandic eruptions from Grímsvötn and Bárðarbunga‐Veiðivötn systems (including V‐Sv tephra). We also find four silicic tephra populations, one of which we link to the Jala Pumice of Ceboruco(Mexico) at 941 ± 1 CE. Triple S isotopes, Δ33S, spanning 936–940 CE are indicative of upper tropospheric/lower stratospheric transport of aerosol sourced from the Icelandic fissure eruptions.