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Exploring tephra records in the Azores peatlands

Adriano Pimentel1\, Ricardo S. Ramalho2,3, Pedro Raposeiro4,5, Armand Hernández6, Mariana Andrade 7, Martin Souto4,5, José Pacheco1

  • Affiliations: 1Instituto de Investigação em Vulcanologia e Avaliação de Riscos (IVAR), Universidade dos Açores, Ponta Delgada, Portugal; 2School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK; 3IDL Instituto Dom Luiz, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal; 4CIBIO Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Pólo dos Açores, Ponta Delgada, Portugal; 5Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Portugal; 6Universidade da Coruña, GRICA Group, Centro Interdisciplinar de Química e Bioloxía (CICA), A Coruña, Spain; 7GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany

  • Presentation type: Poster

  • Presentation time: Friday 16:30 - 18:00, Room Poster Hall

  • Poster Board Number: 153

  • Programme No: 3.4.31

  • Theme 3 > Session 4

Abstract

Knowledge of a volcano's eruptive history is essential for volcanic hazard assessment and forecasting its future eruptive behaviour. The study of water-laden sedimentary archives revolutionised the reconstruction of past volcanic activity, as they usually hold a better-preserved tephra record than subaerial environments. Studies in the Azores revealed numerous tephra layers in lacustrine and marine sedimentary records, but the potential of peatlands as another, notionally better, sedimentary archive remains unexplored. Peatlands are ubiquitous in the Azores highlands due to their heavy rainfall conditions and cool, even temperatures. Critically, peatlands (many of which were former lakes) constitute ideal traps for preserving tephra layers, resulting in expectedly rich, easily dated (with radiocarbon) sedimentary records from which uniquely detailed volcanic activity reconstructions can be derived. To take advantage of the ubiquitous peatlands, we devised a multidisciplinary project that will tap this record, for the first time in the Azores, and explore its potential for the detailed reconstruction of the eruptive history of Pico Island, which is characterised by numerous basaltic monogenetic eruptions with small tephra dispersal footprints, thus requiring widespread and easily accessible sedimentary archives for an effective reconstruction of its past volcanic activity. We plan to undertake a prospective coring campaign on Pico's peatlands, followed by stratigraphic, geochemical, paleoenvironmental, and geochronological correlations of peat sequences to test their potential for detailed eruptive history reconstructions. This project will also offer insights into Holocene climate changes and the sensitivity of peatlands as major carbon sinks in the Azores. ExTRAP project funded by FCT ref. 2023.12382.PEX