Madhvi Gor

Integrating petrology, field observations, and modelling to study lava rheology, focusing on crystallisation rates and implications for volcanic hazard assessment.

PhD project title:

Geochemical and Physical Evolution of Lava Flows

Madhvi Gor

Project description:

Lava flows pose a major hazard to communities near active volcanoes, with basaltic lava flows posing the greatest risk due to their rapid advance rates. Notable examples include the 2002 Nyiragongo lavas which destroyed 15% of Goma city displacing 120,000 people [Baxter et al., 2004]; the 2018 Kilauea lavas in Hawaii, which buried 30 miles of roads [National Park Service, 2018] and the 2021 La Palma lavas which damaged nearly 3000 buildings [González- de-Vallejo et al., 2024]. As one of the few volcanic hazards that can be closely monitored in real time [Pinkerton and Wilson, 1994], lava flows provide valuable opportunities to study flow emplacement and how they evolve under natural conditions.

Lava flows can be modelled due to their repeatable behaviour, but their movement is largely governed by rheology—the way materials flow and deform. Lava rheology evolves as it cools and flows, influenced by factors such as chemical composition, temperature, crystal growth, and gas bubble content— all of which affect how far the lava travels [Griffiths, 2000].

While field studies have extensively documented flow dynamics, rheological descriptions remain limited. Existing numerical models either simplify physical properties (e.g. GIS-based steepest slope models) or rely on assumptions (e.g. thermo-rheological models) that introduce uncertainties. A key challenge is understanding how lava rheology changes during flow.

Laboratory experiments have aimed to constrain rheology, but they often fail to represent natural conditions, particularly the presence of crystals and bubbles in real lava. The 1706 Garachico lava flow in Tenerife has been petrologically less studied. My research will use petrographic techniques—geothermometry, crystal size distribution, electron microprobe analysis and diffusion modelling—alongside field morphology analyses to assess how crystallinity, vesicularity, texture, and mineralogy evolve down-flow.

These constraints will be incorporated into numerical models to test flow length predictions and assess cooling assumptions. By integrating field, petrological, and modelling approaches, this work aims to improve our understanding of lava rheology and enhance lava hazard prediction.

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