A team of University of Rhode Island scientists are currently at sea in the Atlantic Ocean using sediment cores extracted from up to 6,000 meters down to help understand Earth’s climate.
The 38-day expedition, led by Graduate School of Oceanography professors Arthur Spivack and Rob Pockalny, is currently atop an underwater mountain chain known as Researcher Ridge aboard the R/V Knorr.
“We know the ocean is a big part of climate, so we are collecting seafloor material from which we can reconstruct the past biology and physics of the ocean,” Spivack said during an online chat directly from Researcher Ridge. “The geography there gives them the ability to extract cores at varying depths so they can examine the differences between those different zones.”
“Specifically, we collect long columns of sediment, called cores, and analyze these to infer past chemical, biological and physical conditions,” Spivack said.
The cores are examined similarly to ice cores extracted from glaciers. “However, one big difference is we can’t see what we are trying to collect from the ocean abyss,” said Spivack. As mud accumulates on the seafloor with time, it can indicate how carbon dioxide levels have changed.
The expedition, funded by the National Science Foundation, includes 22 scientists, largely URI graduate students in geology, microbiology, chemistry and oceanography. Along side them are approximately 10 technicians and a crew of around 20 who operate the ship. “It takes a big team,” Spivack said.
Their ship, the Knorr, includes a specially designed rig capable of drilling into the seafloor at extreme depths. The ship is widely known for supporting expedition that discovered the sunken HMS Titanic in 1985, led by URI professor Robert Ballard.
The team has collected samples from two of what will hopefully be seven to eight sites, each with three cores of varying lengths, according to Spivack. “We end up with a lot of mud. Since it is expensive and difficult to get out here, we try to collect as much material as possible. This taxes everyone to their limit.”
Sonar helps the researchers narrow down drilling locations based on topography and sediment type. Once they are located, team members of varying specialties get to work to prepare, drill, and examine the cores. “It really is a team effort and communication between the groups is key,” said Graduate School of Oceanography student Mary Dzaugis who is serving as a core curator for the cruise.
The expedition, which departed October 25, experienced rough seas to start, but having now crossed into the tropics, has seen perfect weather. “Sunny, low 80’s, slight breeze. Not much to complain about,” Spivack said.
The team has been posting updates from the expedition on their blog at http://researcherridge2014.wordpress.com/ and a live map showing their location is being updated by the Woods Hole Oceanographic Institution at http://www.whoi.edu/page.do?pid=8581.