Volcanic Risk Assessment in Asia

The 1815 Tambora eruption, the deadliest in recorded history, had far-reaching and long-lasting impacts on our planet. The vast quantities of ash ejected from the vent into the atmosphere altered the global climate for many years, causing dramatic drops in temperatures and worldwide crop failures that earned 1816 its nickname of “the year without a summer”. Aside from a large asteroid or comet impact, large explosive volcanic eruptions are the only natural hazard with the potential for such widespread consequences. However, and despite the high stakes, “volcanoes are underappreciated in the insurance industry”, as geologist Dr. Susanna Jenkins points out. “Volcanic hazard and risk assessments are far less developed than for earthquakes or hurricanes”. In Southeast Asia – where 50% of all fatal incidents at volcanoes happen – many populated areas lie within 100 km of at least one potentially active volcano. Yet, the dearth of historical records on past events gives little clue as to what risks they present. In a Joint Research Initiative (JRI) with AXA, Dr. Susanna Jenkins, from the Earth Observatory of Singapore, Nanyang Technological University, is leading a project that aims to improve volcanic risk assessment in Asia. Her investigation focuses on modelling the dispersal, likelihood and impact of the most frequent and widespread of volcanic hazards: ash.

The ash that is expelled from a volcano during an eruption is composed of very small (< 2 mm) rock, mineral or glass particles. Their size means they can be carried by wind over long distances, causing serious disturbances while in the air or when they fall to the ground. For instance, as the 2010 Eyjafjallajökull volcanic eruption showed, ash can cause problems for aircraft engines, forcing airlines to ground planes in the affected areas. If the ashfall is thick, it can cause serious damage to infrastructure, food or water supply. Moreover, unlike the ash produced by burning wood, volcanic ash can be dangerous for health. Its particles can cause eye, nose and lung irritation, as well as breathing problems. “Other volcanic hazards, like pyroclastic, mud or lava flows, are constrained in space to a few to tens of kilometers at most. The range of likely impacts from ash, and the distance over which they occur, is likely to be much, much greater, and it has the potential to disrupt a lot of activities”, Dr. Susanna Jenkins explains.

Assessing volcanic ash hazard footprints in Asia

In the language of insurance, a large volcanic ash plume represents what is commonly known as a low-probability, high-intensity event. To appropriately manage the risks posed by such disasters, insurers use complex models that generate a robust set of simulated events to estimate the damage and prepare for the financial impacts. “AXA protects many customers against volcanic eruptions, especially in Asia. To offer this kind of protection, we are asked by regulators and local teams to estimate the economic impact of an extreme eruption event ", explains Mathis Joffrain, head of the project on AXA’s side, and a senior natural catastrophes modeler at AXA Group Risk Management. "Because these events are extremely rare, this calculation is a challenge”.

Indeed, without information from analogous well-studied eruptions, ash dispersion models need to solve physics- based equations over large geographical scales, which is time- and resource-intensive, and thus computationally inefficient. Using recent advances in numerical modelling, the present project seeks to overcome this obstacle. The first aim of the project is to develop a computationally efficient probabilistic ash dispersal model that better simulates the hazard footprints. Once the model is ready, a country-specific version of the model will be developed, to quantify the spatial extent and intensity of volcanic hazard in countries within southeast Asia. “This is a significant undertaking, says Dr. Jenkins. it requires frequency-magnitude relationships and eruption source parameters to be defined for all credible eruption scenarios from all potentially active or active volcanoes in the country. For this, we aim to collaborate and liaise closely with local agencies, using their regional data to supplement large databases like the ones created by the Smithsonian Institution Global Volcanism Program (GVP) or the Large Magnitude Explosive Volcanic Eruptions (LaMEVE)”. Finally, the last work package will assess volcanic loss from a future hypothetical eruption at Mount Fuji in Japan. In other words, this final step will focus not just on hazard, but also on risk, coupling the previously developed ash hazard modelling approach with exposure and vulnerability assessments. “The effort will expand beyond solely major building damage, to cover critical infrastructures, agriculture and other causes for economic loss”.

Catastrophe models are highly complex in nature. They entail the pooling of various fields of expertise, including state-of-the-art statistical and mathematical methods, in-depth scientific understanding of the phenomena at play and, of course, the perspective of a practitioner. The present joint initiative represents a perfect opportunity for synergy of all these aspects. Furthermore, AXA’s strong involvement in Asia, its contact with real-world end users in countries within the region, will give the research societal relevance and help steer efforts towards the development of a practical tool.

Volcanic Risk Assessment in Asia

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