![\"Submarine](\"https:\/\/blogs.agu.org\/landslideblog\/files\/2017\/12\/17_12-Canary-1-e1513150168514.jpg\")
The location of theODP drilling sites on the Madeira Abyssal Plain. Maps taken from the report of the Shipboard Scientific Party in 1995<\/a>.<\/p><\/div>\n The cores record a long succession of large submarine landslides.\u00a0 Hunt and Jarvis (2017)<\/a> propose that these represent a succession of failures that occurred as the Canary Islands underwent ” inception, ascension and emergence during the seamount-phase of growth and later subaerial-phase of growth”.\u00a0 In other words, as the islands formed the submarine slopes became oversteepened, and underwent failure (possibly triggered by a seismic event or by magma emplacement), generating these vast submarine landslides.\u00a0 They find that on average a major landslide has occurred every 220,000 years over the last seven million years, which is more frequent than occurred prior to this point.\u00a0 Interestingly, they have also been able to associate specific landslides to the formation of specific islands.\u00a0 The authors suggest that the record indicates that the early growth phases of volcanic islands are associated with a high rate of submarine landslides.<\/p>\n Such large submarine can of course represent a hazard as they have the potential to be tsunamigenic. However, Hunt and Jarvis (2017)<\/a> address this issue in what is I think the most important element of this piece of work.\u00a0 They note that:<\/p>\n “These distal deposits representing failures of the submarine flanks of the Canary Islands and adjacent seafloor predominantly comprise two or more silt layers in the basal portion of the deposits (85% of those beds thicker than 10\u2009cm), which are separated by centimetres to decimetres of turbidite mud. This implies that the slides were predominantly multi-stage, thus despite their large-volume, their tsunamigenic potential is reduced.”<\/p><\/blockquote>\n In other words the deposits demonstrate that the failures did not occur as a single large event, but instead as a multistage failure, presumably through retrogression and lateral growth of the failure mass.<\/p>\nReference<\/h4>\n