Melville docked along the pier in Papeete, Tahiti
R/V Melville is a research vessel from Scripps Institute of Oceanography near San Diego California. The National Science Foundation funds the operation of the ship as well as the research expedition.
Our cruise trackline in the southwestern Pacific Ocean. The cruise was dubbed "SPLAT" (South Pacific LAitudinal Transect) by the original proponents.
The R/V Melville is 279 ft long and well-equipped to conduct geophysical studies and collect sediment cores from the ocean floor.
The scientific party included scientists, students and technicians from the University of Michigan, Boise State, Oregon State, Texas A&M, Indiana University of Pennsylvania and the U.S. Coast Guard.
Traditional Polynesian sculpture found at Bougainville Park, Papeete.
Bougainville Park is a beautiful tropical park area near the pier in Papeete. Bougainville claimed Tahiti for France a few months before Capt. Cook arrived there.
In the heart of Papeete is a terrific open-air market selling food, fish and local crafts.
Our research expedition departed Papeete in early February, 2005 during the Chinese New Year celebration.
A pilot boat guides the ship from the harbor and provides safe passage through the barrier reef that surrounds the island of Tahiti.
This was our last view of land for the next 41 days at sea.
Two co-chief scientists led the expedition. Here, Mitch Lyle is making last-minute arrangements in the airport.
Dave Rea was the other co-Chief Scientist. His experience mapping geophysical data on the seafloor was particularly useful during the expedition.
The ship's captain is also key to a successful research cruise. Oddly, I didn't have a single photo of Capt. Chris, but here's the bridge control room where he drives the boat.
Leading the coring operations is Chris Moser from Oregon State University.
Our expedition was a site-survey cruise designed to gather preliminary data (geophysical and sediment cores) to support a proposal to return to this region at a later date with a larger drill-ship. Shown is the output generated by some of the seismic recording devices that run continuously.
After processing by scientists, a clear image of seafloor crust and sediment cover can be seen.
Another main objective of this cruise was to recover sediment cores that can be studied in detail back at our home institutions.
The ship contains an impressive array of equipment. Just about every inch of deck space is used on the Melville.
Coring and geophysical operations occur on the fantail (rear) and along the starboard (right) side of the vessel. Large cranes and A-frame winch/pulley systems assist scientists in deploying and retrieving the heavy equipment.
The piston core is our preferred coring device. It consists of a very heavy weight stand with a 60ft (18m), large-diameter core barrel assembly attached. A piston is placed on the inside of the coreliner and helps to recover cores with minimal disturbance. When filled with sediment, the entire device weighs nearly 6 tons.
The core barrel is too long to remove the sediment while vertical, so the entire coring system is rotated horizontally along the side of the ship.
Scientists assist coring operations along every step of the process.
Coring operations occur whenever conditions are safe enough. The weather started getting pretty rough as we approached higher latitudes (and Typhoon Percy).
Shorter gravity cores also are taken at every site as a "trigger" mechanism to release the piston core near the bottom of the ocean.
During this expedition, we were fortunate to have two U.S.Coast Guardsmen training with us. They did much of the hard labor!
Inserted into the core barrel is a plastic core liner that can be removed later when filled with sediment. The liner is pre-labeled to make the job of core curation easier.
The core-liner (sched-40 PVC pipe) is labeled and marked before insertion to the pipe.
Scientists gather around the cores as they arrive on deck. (IUP student Matt Bolyn in orange hard-hat)
Bulk measurements of porosity, density, resistivity, and magnetic susceptibility are determined while cores are still "whole" (i.e. before they are split and described).
When bulk measurements are completed, the cores are split lengthwise into two halves - one is reserved for sampling by the scientists, the other is "archived" for future studies.
As soon as the cores are split, scientists make observations of sediment color, composition, and any other sedimentological features that are present.
Co-chief scientist Dave Rea (University of Michigan) is shown next to a section of core displaying a distinct transition from brown colored clay-rich sediments near the top to lighter colored carbonate material deposited deeper (during older times).
Sediment descriptions are an important duty performed by the scientists aboard the vessel. Often they surround interesting discussions about ideas related to what causes changes in the type of sediment deposition.
Once the sediment cores have been described, they are placed in long plastic "D-tubes" then boxed for shipping back to the core repository located at Oregon State University. Cores are shipped and stored in refrigerated conditions to mimic the natural temperature of the seafloor environment.
Seismic studies are also conducted during the research cruise to provide a larger picture of the sedimentary depositional environment. A large airgun that emits a sound pulse is towed behind the ship along with a very long streamer of hydrophones that "listens" for the returning sound pulse bouncing off the sediment layers at bottom of the sea floor.
The hydrophone streamer is nearly a quarter of a mile long and is filled with sensitive electronic equipment. A group of scientists helps deploy and retrieve the streamer every time a seismic survey is conducted.
All this data is processed into digital data using sophisticated (and electronically complicated) equipment.
Inside the main lab of the ship are a variety of computer monitors and recording devices that process and display data collected by the ship.
At least two scientists "stand watch" 24hrs a day, 7 days a week. Their duties include routine recording of the ship's position and checking readouts to make sure all equipment is working properly.