Sara Osman

Sara Osman


My PhD research focuses on the impact of tephra fall loading on buildings, using Ascension Island as a case study. My laboratory tests investigated the geomechanical properties of tephra and assessed its sliding behaviour on roofs, validated with field observations in La Palma, Canary Islands. I have used tephra dispersion modelling for Ascension to investigate the tephra fall hazard and possible impacts on buildings for a range of eruptive scenarios and developed a GIS tool to enable the risk of roof collapse under tephra fall loading to be assessed at a buidling scale. I am funded by the NERC Panorama DTP and the BGS University Funding Initiative (BUFI).

Research interests

My research interests include tephra dispersion modelling and hazard/risk assessment related to tephra fallout. My Masters research included:

  • Assessing the hazard associated with the sedimentation of large clasts from lava fountain-fed plumes at Mount Etna.
  • Compiling grain size distributions for both phreatomagmatic and magmatic eruptions and using the NAME model to investigate how the grain size distribution used to initialise an ash dispersal model impacts the modelled ash plume.

Publications: Osman, S., Thomas, M., Crummy, J., Sharp, A., Carver, S. (2023) Laboratory tests to understand tephra sliding behaviour on roofs J Appl. Volcanol. 12, 11.

Osman, S., Thomas, M., Crummy, J., Carver, S. (2022) Investigation of geomechanical properties of tephra relevant to roof loading for application in vulnerability analysesJ Appl. Volcanol. 119 .

Osman, S., Beckett, F., Rust, A., Snee, E. (2020) Sensitivity of volcanic ash dispersion modelling to input grain size distribution based on hydromagmatic and magmatic deposits. Atmosphere, 11, 567.

Osman, S., Rossi, E., Bonadonna, C., Frischknecht, C., Andronico, D., Cioni, R., and Scollo, S. (2019) Exposure-based risk assessment and emergency management associated with the fallout of large clasts at Mount Etna, Nat. Hazards Earth Syst. Sci., 19, 589–610,



  • 2018-2019 MSc by Research, University of Bristol.
  • 2015-2017 MSc Geological and Environmental Hazards, University of Portsmouth.
  • 2008-2013 BSc (Hons) Natural Sciences (Earth Sciences), Open University.

Research groups and institutes

  • Institute of Geophysics and Tectonics
  • Volcanology