created by such collapses are easily recognized.
They include calderas (Taburiente in La Palma or
Las Cañadas in Tenerife), valleys with knife-cut
cliffs—calledladeras in Spanish—delimiting the
collapse-formed valleys (Laderas de Güímar or
Ladera de Tigaiga, in Tenerife) or concave cliff-archs
such as those in the Anaga (Tenerife), Tamadaba
(Gran Canaria), or Jandía (Fuerteventura) massifs.
The sudden collapse of volcanic island slopes
and consequent debris avalanches has the potential
to generate tsunamis of extreme magnitude (mega-
tsunamis), which may not only have highly
destructive impacts on the coasts and low areas of
nearby islands but also impact far-distant land-
masses. For example, it is estimated that the El
Golfo collapse (El Hierro) produced a mass44 ISLAND ENVIRONMENTS
100 km100 kmLa PalmaLa Gomera TenerifeEL HierroNiihauMaui
KahoolaweHawaiiLanaiMolokaiOahuKauaiGran CanariaCANARY ISLANDSHAWAIIAN ISLANDSLanzaroteFuerteventuraFigure 2.22Mega-landslides in two oceanic island archipelagoes: (a) Landslides recognized in the Canaries (b) Landslides recognized in Hawaii
(Redrawn from Carracedo and Tilling 2003, Fig. 2.18).