New model combines tsunami loss information with earthquake-shaking damage output

Willis Re, the reinsurance division of Willis Group, has launched its first Japan Tsunami Model to advance the industry’s understanding of catastrophic tsunami losses.

Developed in-house alongside the Willis Research Network, it is the first tsunami model with probabilistic and deterministic modelling functions to be created by a broker.

The new model combines tsunami loss information with earthquake-shaking damage output. It provides Willis Re and its clients the latest intelligence to quantify and manage risk from these extreme events, where historically losses have been little understood.

Willis Re Japan regional director William Thompson said: “The tragedies of the Indian Ocean tsunami in 2004 and the tsunami that followed the Tokohu earthquake in 2011 illustrated how damaging these catastrophes can be. They highlighted the need to better understand and quantify the risks from secondary perils.

“Japan’s earthquake risk has been rigorously investigated and modelled but the complexity of modelling tsunamis has led to a significant gap in the industry’s ability to quantify risk for severe earthquake events. The Willis Japan Tsunami Model is another vital step towards closing this gap and providing Willis Re clients with the most comprehensive view of risk.”

Willis Re has worked closely with Tohoku University and University College London (UCL) on the model since 2010.

UCL director of EPICentre Tiziana Rossetto said: “Our focus has been on the development of the vulnerability model, linking tsunami intensity with mean damage and loss. There are significant obstacles to estimating tsunami losses owing to limited availability of data for low-frequency/high-severity events.

“The current tsunami vulnerability model utilises rigorous statistical analysis of data from the 2011 Japan tsunami, resulting in a model that represents the state-of-the-art in estimating losses per building due to tsunamis.”