Quantification of ash sedimentation dynamics through depolarisation imaging with AshCam

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Ryunosuke Kazahaya
  • Paul Wallace
  • Felix Von-Aulock
  • Yan Lavallée
  • Giuseppe Salerno
  • Simona Scollo


Even modest ash-rich volcanic eruptions can severely impact a range of human activities, especially air travel. The dispersal of ash depends critically on aggregation and sedimentation processes – however these are difficult to quantify in eruption plumes. Here, we image ash dynamics from mild explosive activity at Santiaguito Volcano, Guatemala, by measuring the depolarisation of scattered sunlight by non-spherical ash particles, allowing the dynamics of diffuse ash plumes to be investigated with high temporal resolution (>1 Hz). We measure the ash settling velocity downwind from the main plume, and compare it directly with ground sampled ash particles, finding good agreement with a sedimentation model based on particle size. Our new, cost-effective technique leverages existing technology, opening a new frontier of integrated ash visualisation and ground collection studies which could test models of ash coagulation and sedimentation, leading to improved ash dispersion forecasts. This will provide risk managers with improved data quality on ash location, reducing the economic and societal impacts of future ash-rich eruptions

Bibliographical metadata

Original languageEnglish
Article number15680
JournalScientific Reports
Issue number1
Early online date24 Oct 2018
Publication statusPublished - 2019

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