-Recurrence interval ~100000 years for all Canary Islands, ~300000 years per island (Whelan and Kelletat, 2003).

-Majority of 14 large landslides within the last 1 million years (Whelan and Kelletat, 2003).

-50 to 500 km³ debris avalanches spread over 130 km from their source (Whelan and Kelletat, 2003).

-~25% of islands' mass removed by landslides (Whelan and Kelletat, 2003).

Figure 1: Landslide debris fans of the Canary Islands and dates of deposit (Whelan and Kelletat, 2003).

-Cumbre Vieja has developed on the collapse scar from a large landslide on Cumbre Nueva (Day et al., 1999).

-Collapse scar fill may be associated with structurally weak units: avalanche deposits, hydrated tuff, erosional sediments (Day et al., 1999).

-Boreholes confirm alluvial fan breccias and clay matrix rich debris on northern area of the scar (Day et al., 1999).

-If this material is present throughout collapse areas as it appears, it produces a concentrated zone of weakness in the volcano (Day et al., 1999).

Figure 2: Inferred collapse scar upon which Cumbre Vieja developed (Day et al., 1999).