Presented by: Prof. Valentin R. Troll, Uppsala University

Abstract: Half a century after the eruption of the Teneguía Volcano on La Palma in 1971, a new eruption occurred on the island and lasted for 85 days from 19 September until 13 December 2021. This new eruption opened a volcanic vent complex on the western flank of the Cumbre Vieja rift zone, the N-S elongated polygenetic volcanic ridge that has developed on La Palma over the last c. 125 ka. The Cumbre Vieja ridge is the volcanically active region of the island and the most active one of the Canary Islands, hosting half of all the historically recorded eruptive events in the archipelago. The 2021 La Palma eruption has seen no direct loss of human life, thanks to efficient early detection and sensible management of the volcanic crisis by the authorities, but more than 2800 buildings and almost 1000 hectares of plantations and farmland were destroyed. Satellite surveillance enabled accurate mapping of the progressive buildup of the extensive and complex basaltic lava field, which together with monitoring of gas emissions informed the timely evacuation of local populations from affected areas. Lava flows that reached the sea constructed an extensive system of lava platforms, similar to events during earlier historical eruptions, such as in 1712, 1949 and 1971. Long-term challenges in the aftermath of the eruption include protection of drainage systems from potential redistribution of tephra during high rainfall events, the use of the large surplus quantities of ash in reconstruction of buildings and in agriculture, and the crucial concerns of where and how rebuilding should and could occur in the aftermath of the eruption.

Biography: Professor Valentin R. Troll is a one of the world’s leading volcano researchers and graduated from St Andrews University, UK in 1998 and received his PhD from the GEOMAR Research Centre at the University of Kiel, Germany, in 2001. After completing his doctorate, Troll lectured in volcanology and geochemistry at Trinity College Dublin (2001-2008), during which time he habilitated at the Blaise Pascal University Clermont-Ferrand, France, in 2006. In early 2008, he took up the Chair of Petrology at Uppsala University, Sweden, which he currently holds. His research interests revolve around volcanic and magmatic processes, volcanic phenomena, and resources and how these shape society and human interaction with nature in volcanically active regions.

The Graduate Seminar is mandatory for all ErSE and ERPE students. Kind reminder to sign the participants list in order to register your attendance.

NOTE to all: We are back in person, students - please visit the venue in Building 9, room 2325, to attend the seminar