HR: 10:40h
AN: V11G-02    [PDF]
TI: North Kona Slump: a Recent Giant Submarine Landslide in Hawai`i
AU: * Fryer, G J
EM: gerard@hawaii.edu
AF: School of Ocean \& Earth Science \& Technology, University of Hawai`i at M\={a}noa, Honolulu, HI 96822 United States
AU: McMurtry, G M
EM: garym@soest.hawaii.edu
AF: School of Ocean \& Earth Science \& Technology, University of Hawai`i at M\={a}noa, Honolulu, HI 96822 United States
AU: Smith, J R
EM: jrsmith@hawaii.edu
AF: School of Ocean \& Earth Science \& Technology, University of Hawai`i at M\={a}noa, Honolulu, HI 96822 United States
AB: Four Giant Submarine Landslides (GSLs) scar the west flank of Mauna Loa and adjacent Hualalai, two volcanoes of the Big Island of Hawai`i. Other than the Alika 2 slide ($120\pm 10$\thinspace ka), the ages of the GSLs are only poorly known. From sidescan sonar and multibeam bathymetry the South Kona GSL is older than Alika 1, and Alika 1 older than Alika 2, but where North Kona fits into this sequence is unclear. Because Alika 2 levees appear to cross the North Kona debris field, North Kona has been assumed to be more than 130\thinspace ka. More recent mapping, however, suggests that the apparent right levee of the Alika 2 debris avalanche may actually be the deformation front at the base of North Kona. Farther north, the North Kona Slump truncates the entire sequence of drowned terraces (18--430\thinspace ka) descending the submarine slope of Hualalai. A shallower terrace, previously undescribed, traverses the slope of Hualalai between 100 and 150\thinspace m depth. The terrace is probably the drowned reef from the 4 to 6\thinspace ka Holocene high stand; whether it has been disrupted by the North Kona Slump is unclear. Morphologically, the North Kona Slump is very similar to the currently-active Hilina Slump of K\={\i}lauea. Indeed, a magnitude 6.5 earthquake in 1929 may indicate that the North Kona Slump is itself still active. The initial North Kona failure apparently occurred near the beginning of the Holocene Transgression, a timing supporting the hypothesis that large flank failures of oceanic island volcanoes have a climate trigger.
DE: 3022 Marine sediments--processes and transport
DE: 3045 Seafloor morphology and bottom photography
DE: 4564 Tsunamis and storm surges
DE: 8499 General or miscellaneous
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting