Looking Further Back in Time at Flank Degradation Processes and Volcanic Edifice Evolution on the Northwestern Hawaiian Ridge

University Of Hawaii, Honolulu

Investigators

Abstract

The project will analyze and interpret multibeam bathymetry data obtained during two highly successful research expeditions to the Papahânaumokuâkea Marine National Monument in the Northwestern Hawaiian Islands. Much of the history of the volcanoes located in this area west of the main Hawaiian Islands remains poorly documented. This study focuses on understanding the formation of the giant landslides that are common on the Hawaiian Islands. The primary goals are to document how volcanoes build and then collapse over time and to document the frequency and size of landslides to assess the hazard that they present in Hawaii and other island nations. Large landslides have the ability to generate tsunamis and thus pose a significant risk to society. The results will aid the management and perpetuation of the national monument, most notably the biological communities living on the volcanoes. A graduate student will be trained in data analysis and interpretation. An extensive set of geophysical data was acquired from the Hawaiian Ridge during two cruises on the Research Vessel Falkor in 2014. The purpose of the two 36-day expeditions, primarily sponsored by the Schmidt Ocean Institute in conjunction with NSF and NOAA, was to carry out multibeam and potential field mapping within the the Papahânaumokuâkea Marine National Monument in the Northwestern Hawaiian Islands. The proposed work will use the bathymetry data to examine the nearly 50 giant submarine landslides and their deposits previously mapped in the region using lower-resolution data collected over 20 years ago. The main objective is to carry out detailed interpretations of the older GSLs to provide a larger statistical base, a greater variety of source edifice morphologies and structural settings, and a longer temporal comparison with the giant submarine landslides in the main islands and worldwide.