A causal approach to identifying site-specific trigger factors to mass movement processes

This paper addresses the issue of identifying site-specific trigger factors to be linked to a geohazard event. Identifying trigger factors in geohazard assessments usually presents challenges that originate from the difficulty in developing accurate ground models due to, e.g., unknown or future ground conditions. This difficulty makes it problematic to conclusively inform the choice of a specific trigger linked to a geohazard event. Unfortunately, the geohazards literature does not provide a structured approach to tackle this problem. Accordingly, approaches addressing this difficulty are required. To this end, an approach to identifying specific trigger factors for a site is developed. The approach reported here emphasises the identification of triggers informed by structural causal models. The approach is illustrated based on the outputs from an exemplary geohazard assessment that was conducted for the Sigsbee escarpment in the northern Gulf of Mexico, a site involving submarine landslides. By doing so, evidence about the relevance and usefulness of the proposed approach is provided.