When Sam McNichol boarded the Atlantis on Costa Rica’s Pacific coast, he expected to spend a month collecting deep-sea samples in the mid-Pacific. The McGill PhD candidate did not anticipate that two of his shipmates would have the rare opportunity to witness a volcanic eruption during one of their last days at sea, at a location where no researcher had ever documented such an event before.
“We have this really exciting opportunity to look at what happens immediately after one of these eruptions occurs,” McNichol said, referring to his continuing examination of the samples and data collected. “We stayed on site for three extra days to do this flurry of analysis.”
Led by oceanographer Andrew Wozniak of the University of Delaware, the ship sailed on April 3 to a site 2,100 kilometres west of Costa Rica along the East Pacific Rise, a massive underwater mountain chain spanning thousands of kilometres from west of Mexico to close to Australia. It carried a crew of researchers not only from McGill and University of Delaware, but also Rensselaer Polytechnic Institute (RPI) and Middle East Technical University.
Along this mid-ocean rise, tectonic plates move apart, creating new oceanic crust through volcanic activity. As seawater heats up from magma at these boundaries, hydrothermal vents spew hot mineral-rich water. The crew’s goal was to study the complex carbon compounds emitted by these vents, leading to a better understanding of the dynamics of the largest carbon reservoir on our planet, the ocean.
A rare eruption sighting
During the final days of the expedition, Wozniak and a student diving in Alvin, the ship’s human-occupied underwater research vehicle, came to the surface with more than deep sea footage: they had been the first scientific researchers to witness a mid-ocean ridge eruption at that location and to capture images of magma droplets.
Onboard the Atlantis, researchers quickly called an emergency research meeting. They came up with a plan to take advantage of the rare event, which gave them an exciting opportunity to uncover the chemical and biological mysteries of the formation of a new sea floor, one of the most fundamental processes in the ocean.
The work to understand the impacts of the eruption continues. McNichol plans to look at genomic sequences from samples taken above hydrothermal vents to identify which micro-organisms lived there before the volcanic eruption, and now also has the unique opportunity to find out what happened right afterward.
Oceans and collaborations across borders
McNichol, whose fascination with the deep-sea stems from his oceanographer parents, initially boarded the ship as part of his PhD research in Professor Nagissa Mahmoudi’s Earth and Planetary Sciences lab at McGill. The lab focuses on marine micro-organisms and their role in shaping nutrient cycles. McNichol’s PhD project has taken him around the world and through various projects – from studying how marine bacteria compete for food to the effects of underground heat on bacteria’s carbon food sources.
When Sunita Shah Walter, who sits on McNichol’s supervisory committee and is a Professor at the University of Delaware’s School of Marine Science and Policy, invited him a year ago to join the crew, McNichol jumped at the chance.
“In general, oceanography is a very collaborative field,” McNichol said. “Oceans exist at the intersection between physics, chemistry, biology and geology, so to understand the ocean system, you have to have an expert in each in the conversation, at some point.”
For McNichol, those collaborations made the chance to see the site in person even more meaningful.
“I’m very grateful to have had the chance to see my deep-ocean research site with my own eyes, and I’m excited to see what we can learn from this unique opportunity,” he said.