Abstract:

With the onset of the volcanic unrest of Reykjanes Peninsula, lava hazard simulations have become a very pertinent topic for volcanic monitoring and forecasting in Iceland. Lava flow simulations are an essential tool to forecast lava flow emplacement and are used for long- and short-term hazard and risk assessments before and during eruptions.

However, lava flows are challenging to simulate because it is a complex multiphase and multicomponent fluid; temperature, rheology and emission rate vary in time and space. Adding to the complexity, lava solidifies during emplacement, changing the topography controlling its emplacement. Random effects are also known to strongly influence the processes of pāhoehoe, posing additional difficulty for lava flow simulation codes.

Deterministic codes approach the problem of predicting lava flow fields based on various simplifications of governing physical equations, but they are challenged due to the complexity of real lava flows and the uncertainty of input data. Numerical probabilistic codes do not attempt to tackle the physical complexity of the lava flow dynamics but rely on a large number of simulations of simple flow models with stochastic perturbations to identify potential flow paths and areas of potential hazard.

Volcano observatories around the world have adopted different strategies and models to tackle the challenge of forecasting lava flow hazards. Since 2014, the Icelandic meteorological office have applied the stochastic code MrLavaLoba for their lava hazard assessment. In this talk I will focus on the recent advancements in lava flow simulation using the MrLavaLoba code, focusing on the application to volcanic unrest phases at Fagradalsfjall and Svartsengi.

All are welcome.