Mahukona Survey
The Mahukona survey is located west of the north Kona coast on Hawaii and shows a large area named the Kohala Terrace. We have called it the Mahukona survey for the submarine volcano that forms the western part of the survey area. This area is characterized by a stairstep series of drowned coral reefs that date from as recent as 15,000 years ago, for the shallowest reef at 150-meters depth, to as old as 465,000 years for a reef near the break-in-slope (Clague and Moore, 1991). The new bathymetry and sidescan allow us to determine the distribution of these reefs much more accurately than was previously possible (Clague et al., 1998).
The new data show that the series of reefs were progressively tipped toward the southeast as the island of Hawaii grew. The images also reveal several, previously unknown, submarine eruptive fissures and lava flows that drape the different reefs. These fissures are probably radial vents from Mauna Loa Volcano. The western rift zone of Mahukona Volcano is characterized by numerous flat-topped circular volcanic cones, similar in form to those on the flanks of Ni`ihau. In addition, several pointed cones, including one that is about 650 meters tall, occur along the rift zone. The large pointed cone is constructed of alkalic basalt (Garcia et al., 1990; Clague and Moore, 1991), and probably erupted during the post-shield stage.
| 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 |