URI
oceanographers to examine chemistry deep in seafloor to assess its role in
historic climate changes
Todd McLeish,
URI
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| This will be the last research mission for the R/V Knorr |
Led by Professor Arthur Spivack and Marine Scientist Rob Pockalny at the URI Graduate School of Oceanography, along with Rick Murray from Boston University, the researchers will sail aboard the R/V Knorr to Researcher Ridge, an underwater mountain chain in the Atlantic Ocean just north of the equator, where they will collect samples at water depths from 1,000 to 6,000 meters.
“We’re interested in how climate, the carbon dioxide system, and ocean circulation have worked together from the last glaciation to the present,” said Spivack, who lives in Jamestown. “We’ll be testing several hypotheses about what controls our climate and how it might act in the future based on how it has behaved in the past.”
“Biology and ocean physics both affect carbon dioxide, and you can see how that works based on the chemistry of the water at different depths,” added Pockalny, a resident of Hopkinton. “The sediment contains a recorded history of the chemistry of the ocean, and by inference the biology and physics of the ocean, too. The ocean is a big three-dimensional machine, and how the machine works influences climate.”
The researchers will visit eight sites and collect sediment cores of varying lengths at each site. They will analyze the physical properties and chemical composition of the water trapped in the sediment cores. The trapped water is a sample of the ancient ocean environment.
An additional focus of their work will be to better understand the microbiology of the seafloor sediments – what microorganisms live there, what they do and how they survive. The microbes living in the sediments represent a large component of the Earth’s biomass, and it contains a significant amount of the genetic diversity on Earth. The scientists say that these organisms have highly diverse survival strategies not seen in life anywhere else on Earth.
“The energy demand of these microbes is much lower than any organism observed at the Earth’s surface, and it appears that they live for thousands of years,” Pockalny said. “They can tell us very fundamental things about how life operates, and it’s an analog for how life might survive on other planets in very low energy environments.”
In addition to Spivack, Pockalny and Murray, other scientists involved in the project include URI Oceanography Professors David Smith and Steven D’Hondt and students and researchers from URI, Boston University, California Institute of Technology, Texas A&M University, Indiana University of Pennsylvania, Montana State University and the Japan Agency for Marine-Earth Science and Technology.
The expedition will be the last research cruise for the R/V Knorr, which will be retired by the Woods Hole Oceanographic Institution at the end of the year. Launched in 1968, it is best known as the ship that supported the team of researchers, led by URI Professor Robert Ballard, that discovered the wreck of the RMS Titanic in 1985. It has traveled more than one million miles in its lifetime. The ship’s unique coring rig makes it ideal for collecting core samples of the seafloor.