Probabilistic earthquake-tsunami financial risk evaluation for the District of Tofino, British Columbia, Canada

ABSTRACT

Southwestern British Columbia in Canada has a high likelihood of facing significant earthquake threats in the future. It is exposed to significant seismic and tsunami hazards, originating from the Cascadia subduction zone and shallow crustal and deep inslab earthquakes. This study presents a new probabilistic earthquake-tsunami loss model for the Cascadia subduction zone by focusing on the District of Tofino, British Columbia. The earthquake occurrence and rupture models for the Cascadia subduction zone are developed by incorporating the time-dependency of earthquake occurrence and by adopting a stochastic source modelling approach, which allows for consideration of heterogeneous earthquake slip distributions. The results produce single-hazard and multi-hazard exceedance probability loss curves for earthquakes and tsunamis from the Cascadia subduction zone. In addition, earthquake risks due to other seismic sources are integrated with the multi-hazard loss curves due to the Cascadia events. In this way, a complete financial exposure from all major seismic and tsunami sources is evaluated. These loss curves can be used for determining the insurance rates for multi-hazard and multi-source risk coverage. The results are beneficial for providing more risk financing options via insurance against the future Cascadia and other seismic events.

KEYWORDS:

• Multi-hazard
• earthquake
• Tsunami
• Cascadia subduction zone
• financial risk

Data availability statement

The results for the single-hazard and multi-hazard loss estimations for Tofino may be available from the author upon request. Since some of the data used for the loss calculations are confidential, the data availability request must be decided case by case carefully.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work is funded by the Canada Research Chairs programme [grant number 950-232015], the Natural Sciences and Engineering Research Council of Canada Discovery Grant [grant number RGPIN-2024-04428] and the New Frontiers in Research Fund [grant number: NFRFI-2023-00548].