The Hilo survey was a joint effort between MBARI and the U.S. Geological Survey. The USGS data for the shallow part of the area (Dartnell and Gardner, 1999) were combined with our survey covering the Hilo Ridge rift zone to construct the composite images shown. There are several prominent reefs offshore Hilo, including a 150-meter-deep reef that is about 15,000 years old, a 400-meter-deep reef that is about 125,000 years old, and a 1,150-meter-deep one that is about 425,000 years old.
In addition, several more subtle reefs are present between the 400-meter and the 150-meter reefs. These reefs record smaller changes in Pleistocene sea level than the prominent reefs. Each of these reefs has grown on top of the Hilo Ridge, thereby demonstrating that Hilo Ridge is greater than 425,000 years old (Clague et al., 1998). This age makes it unlikely that the Hilo Ridge is a submarine rift zone from Mauna Kea Volcano as the Mauna Kea shield was still actively growing at that time. It seems most likely that the Hilo Ridge is a long submarine rift zone of Kohala Volcano, as proposed by Reiners et al. (1997). This rift would be comparable in length to the Puna Ridge of Kilauea Volcano and the magmatic processes operative within the rift zone are similar to those documented at Puna Ridge (Clague et al., 1995; Yang et al., 1999). The 1,150-meter terrace is dotted with numerous small volcanic cones. The rift zone below the 1,150-meter terrace is characterized by numerous flat-topped volcanic cones (Clague et al., 1999, in press), one of which has been modified by rift-parallel faulting.
Data locations listed below, or click on name to download.
MBARI provides these data "as is", with no warranty, express or implied, of the data quality or consistency. Data are provided without support and without obligation on the part of the Monterey Bay Aquarium Research Institute to assist in its use, correction, modification, or enhancement.
(Grid Cell Size)
|Grid||Sun Illuminated Image||Acoustic Reflectivity Image
(at 1/2 grid cell size)
|Click on thumbnail to view larger image|
Map view 1
Map view 2
Oblique view 1
|Index Map||Haleakala||Hilo||Kohala||Loihi||Mahukona||Moloka`i||Ni`ihau||Papa`u||Puna Ridge|