Hawaiian landslides have been catastrophic

Volcanic activity and gentle erosion have not been the only forces to shape the Hawaiian islands. Landslide debris has now been mapped off of all the islands. Enormous amounts of material have traveled great distances, indicating that the slides were truly catastrophic. The Nu'uanu and Wailau landslides, shown in the map, tore the volcanoes forming eastern O'ahu and northern Moloka'i, respectively, in half, and deposited blocks large enough to have been given names as seamounts. Tsunamis generated during these slides would have been devastating around the entire Pacific Basin. (See the coral reefs page for evidence that an enormous tsunami hit the shores of Lanai.)

Debris from enormous landslides off O'ahu and Moloka'i extends hundreds of kilometers
Map © 2001 MBARI

Pali above Kane'ohe Bay on O'ahu: the slide-scarp of the Nu'uanu landslide
Photo © 2004 J.B. Paduan