HR: 1330h
AN: V22C-0604    [PDF]
TI: Volcanic Features in the Northwestern Hawaiian Islands Revealed by SWATH Mapping
AU: * Smith, J R
EM: jrsmith@hawaii.edu
AF: Hawaii Undersea Research Lab, SOEST/University of Hawaii 1000 Pope Rd, MSB 303, Honolulu, HI 96822 United States
AU: Miller, J
AF: National Marine Fisheries Service, 1125B Ala Wai Blvd, Honolulu, HI 96814 United States
AU: Evans, B K
AF: NOAA Pacific Hydrographic Branch, 7600 Sand Point Way, Bldg 3, Seattle, WA 98115 United States
AU: Johnson, P
AF: Hawaii Mapping Research Group, SOEST/University of Hawaii 1680 East-West Rd, Honolulu, HI 96822 United States
AU: Weirich, J B
AF: NOAA Office of Ocean Exploration, 1315 East West Highway SSMC3, Room 10144, Silver Spring, MD 20910 United States
AB: The Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve (NWHICRER) has only recently been established, and has already caused an infusion of interest and funds for studies to assess what is there to preserve and how best to do it. The Northwestern chain stretches over 2200 km to the northwest of the 775 km-long Main Hawaiian Islands (MHI). The MHI have only in recent years been systematically mapped with modern multibeam swath sonar systems and the work is not yet complete. With these southeastern islands being the population center, it is easy to imagine the lack of coverage along the Northwestern chain where no one lives except those stationed at remote outposts for scientific study. Manned and robotic submersible studies and limited multibeam mapping have been carried out by the Hawaii Undersea Research Lab every year in the NWHICRER for the past several years though focused on relatively shallow water biological sites. In late 2002, the first dedicated exploratory multibeam mapping expedition took place aboard the new University of Hawaii SWATH ship R/V {\it Kilo Moana}. While the primary mission was shallow mapping on carbonate platforms in support of the NWHICRER boundaries, a large amount of data were collected over the deeper volcanic foundations of the atolls. These surveys revealed dramatic rift zones on the same scale as those in the MHI, sea level terraces, submarine canyons cutting through the platforms with debris chutes continuing down to base of the islands, additional submarine landslide scars and debris fields in more detail than the USGS GLORIA sidescan program of the previous decade, and previously unmapped seamounts with some likely resulting from Hawaiian hot spot activity while others formed during creation of the Pacific Plate. A diving program is planned on many of these features in late 2003 and preliminary results will be presented.
DE: 3000 MARINE GEOLOGY AND GEOPHYSICS
DE: 3045 Seafloor morphology and bottom photography
DE: 8400 VOLCANOLOGY
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting