A Memorial University marine geologist and a team of experts sailed towards their latest research destination recently: the Galapagos Islands.
The multidisciplinary team of scientists was led by Dr. John Jamieson, a professor in the Department of Earth Sciences, Faculty of Science, and the Canada Research Chair in marine geology at Memorial University.
They spent five weeks this fall aboard the R/V Falkor (too) surveying the waters surrounding the Pacific Ocean islands close to the equator and about 1,000 kilometers off the coast of Ecuador.
While at sea, the researchers tested the capabilities of an interferometric synthetic aperture sonar (InSAS) system and focused on mapping and exploring hydrothermal vent fields at three sites north of the volcanic archipelago.
The expedition team was composed of 24 scientists from eight different institutions in Canada, the U.S. and Japan, including four members of Dr. Jamieson’s lab group: post-doctoral fellow Dr. Chris Galley; PhD candidates Caroline Gini and Sarah Moriarty; and master of science student Charles Lapointe.
The Schmidt Ocean Institute sponsored the expedition. The project is also part of the Ocean Frontier Institute BEcoME project, which, along with Mount Pearl-based Kraken Robotics and Mitacs, provided additional funding for the project.
Acoustic images
The testing and development of InSAS was one of the primary objectives of the expedition.
Kraken Robotics, a Mount Pearl-based underwater technology company, developed the InSAS technology for defence and offshore commercial uses.
Dr. Jamieson’s expedition tested the technology as a scientific tool.
InSAS generates maps of the seafloor using sound, resulting in detailed acoustic images.
On this expedition, Ms. Gini’s role was to oversee the planning of InSAS surveys, operating the sonar and processing data.
“I worked closely with the other geologists and biologists on board to discuss the best outcome of a survey in terms of seafloor coverage or limitations,” she said.
She also worked with other mappers who produced bathymetric maps to compare the results from each technique.
Dr. Galley was also part of the mapping team, focusing on assisting in designing the dive tracks, taking notes during dives and processing the magnetic field data to produce data maps.
“It was tough getting any sleep on this expedition knowing it meant missing something amazing,” he said.
The team mapped three areas along the eastern Galapagos spreading centre, a volcanically and hydrothermally active mid-ocean ridge.
Two of the three sites had been previously explored for hydrothermal vents. The third site was unexplored.
Hydrothermal vents eject metal-rich super-heated fluids into the ocean. They are often called “black smokers” because the minerals in the fluid appear as smoke.
“This is a major achievement for this expedition.”
The mineral deposits that form hydrothermal vents can be rich in valuable metals such as copper, zinc, gold and silver, leading to discussions of deep-sea mining.
While deep-sea mining has yet to occur, the team’s work will help understand issues related to the process, such as the distribution and formation of deposits, their potential as a mineral resource and the possible environmental and ecological risks.
“At the third site, we discovered an entire new hydrothermal vent field, which we named Tortugas, in honour of the famous turtles from the Galapagos Islands,” said Dr. Jamieson. “This is a major achievement for this expedition and a validation of the technology and our approach to seafloor exploration.”
Using the remotely operated vehicle (ROV) Subastian, the team mapped, explored and collected samples from the seafloor.
By the end of the expedition, the researchers collected 104 animal samples, 15 of which had never been described in the region.
They also collected 108 rock samples at hydrothermal vents, 41 sediment samples and more than 100 seawater samples.
Ms. Moriarty was tasked with data management for the collected samples.
“My job was to make sure that every bit of information associated with the onboard scientific activities, deployments and samples was recorded and easily accessible to the rest of the science party,” she said.
Ms. Moriarty was also responsible for seawater collection, post-collection processing and filtration.
These samples will be analyzed post-expedition to investigate the abundances of various isotopes at different depths and different distances from hydrothermal vents.
Mr. Lapointe was primarily responsible for processing the collected rock samples.
“This included photographing, cataloguing and subdividing them for different studies. Most samples require freezing within minutes of exposure to air, all while avoiding cross-contamination, which can be a significant challenge.”
Live from the seafloor
Additionally, more than 50 terabytes of video and sonar mapping data from the seafloor was recorded.
Each ROV dive was live streamed and uploaded to the Schmidt Ocean Institute YouTube channel.
These streams, sometimes as long as eight hours, offer a glimpse into the underwater environments surveyed by the team.
The channel also shared weekly update videos featuring team members discussing expedition progress and findings.
Dr. Jamieson’s lab group also shared updates from the expedition on its Instagram account.
“It was amazing that with such an ambitious sampling plan, and half our time being dedicated to mapping, we were able to accomplish our widely varying but interlinked science goals,” said Ms. Moriarty. “This was in part due to Dr. Jamieson’s time allotment strategy, excellent teamwork from everyone involved, enthusiasm for our respective work, the amazing crew aboard the Falkor (too) and the very hardworking espresso machine.”
