Ward and Day 2001 estimated that the unstable part of Cumbre Vieja would be at least wide in north-south direction. In light of the behaviour of other documented sector collapses such as at Mount St. Helens, the headscarp of the unstable part of Cumbre Vieja is likely east from the 1949 fault and the toe of the sector lies at depth below sea level; this latter reconstruction is supported by bathymetric observations west of La Palma. They had not enough information with which to estimate the thickness of the block but assumed that it would have a volume of about and the shape of a wedge, comparable to the 566,000 Cumbre Nueva giant landslide also on La Palma.