During the expedition, ROV Tiburon completed 57
dives ranging from 150 meters to 3,820 meters depth at various locations.
MBARI scientists focused their efforts on four research themes around the
islands: volcanic processes, deep flank structure of the islands, drowned
shorelines, and submarine canyon processes. High-resolution base maps of
the region collected by MBARI in 1998 were critical in targeting the
David Clague, lead scientist of the expedition and
geologist at MBARI, said, "Our high-resolution bathymetric maps
revealed a collection of interesting seafloor features. With Tiburon
and the base maps, we were able, for the first time, to image these
seafloor features and to collect very targeted samples."
In one surprising finding, the video and samples
collected by Clague and his colleagues suggest that submarine volcanoes
can erupt explosively, even in deep water, and that the processes may be
more similar to volcanoes on land. For example, layers of ash seen at
1,500 meters depth, such as those seen off Kauai, are evidence of
MBARI’s high-resolution bathymetry of Hawaii first
revealed the presence of numerous flat-topped volcanoes on the seafloor
around the islands. Clague and his colleagues had theorized that these
"pancake" volcanoes—imagine the aspect ratio of a U.S. nickel—were
created as continuously overflowing lava ponds rather than from erosion of
taller structures. The video images from Tiburon captured evidence
of this process to support this new theory.
"We’ve learned more about submarine volcanic
processes in Hawaii in the last three years than was known in the previous
60 years," said Clague.
The recent Tiburon dives also allowed researchers
to image submerged coral reefs, markers for the former shoreline of the
island. The Hawaiian islands sink into the ocean at a measurable rate as
they move off the hot spot that provides the magma to make them. The Tiburon
images revealed ancient coral reefs that were partially dissolved when sea
level fell faster than the island subsided. Future studies of the samples
collected will be focused on how these reefs can be indicators of past
Other researchers involved in the expedition will
present results from their studies of submarine canyon processes, plunge
pools, and heat flow around the islands. The large size of seafloor
features, high activity of volcanism, and rapid rates of subsidence make
the Hawaiian islands an ideal place to study geologic processes.
Related presentations, Monday, December 10
MBARI first authors
General Ocean Sciences Contributions
||V12B-0969: MBARI's 2001
Hawaii Expedition using the R/V Western Flyer and ROV Tiburon.
*D A Clague, C K Paull, H G Greene, K Jordahl, A S Davis, Shipboard
[13:30 MC Hall D, Poster]
||V12B-0983: Plunge Pools in
Hawaiian Submarine Canyons. *D W Caress, H G Greene, C K Paull, W Ussler,
D Clague, J G Moore, N H Maher. [13:30 MC Hall D, Invited Poster]|