Michaela Barnes is settling back into classes at the Marine Institute (MI) after a productive summer of seafloor mapping off the coasts of Hawaii and Alaska.

The Clarenville native, who is in the final leg of a four-year ocean mapping program in MI’s School of Ocean Technology, had a unique opportunity to participate in mapping new lava deposits that are changing the underwater landscape near Hawaii’s Kilauea volcano.

In all, she spent 49 days at sea.

“It was a great experience – it was incredible,” she said. “I’ve never been at sea before and I loved it.”

Nautilus voyage

Ms. Barnes spent more than two weeks as a seafloor mapping intern aboard the Exploration Vessel (EV) Nautilus as it left Sidney, B.C., in August to survey a series of unmapped Pacific seamounts on its way to Hawaii.

Once there, the vessel surveyed a seafloor changed by millions of cubic metres of lava flowing from Kilauea volcano between May and August.

“That was pretty exciting,” she said. “There’s a new coastline that is being made because the lava is flowing into the ocean and cooling. So it’s a bit shallower now and there are new features on the seafloor.”

This new layer of seafloor spans more than three square kilometres.

The data acquired will enable researchers to learn how much lava has been deposited on the seafloor, examine early-stage lava formations and use this baseline data to monitor future changes.

Ocean mapping

Equipped with multibeam sonar in hull of the ship, the Nautilus is able to collect data on water depth, the water column and characteristics of the seafloor surface sediment.

The vessel is operated by Ocean Exploration Trust, which was founded in 2008 by internationally renowned deep-sea explorer Dr. Robert Ballard, best known for discovering the RMS Titanic.

As the Nautilus cruises back and forth in straight lines, it sends multiple sonar beams toward the seafloor. Those pulses bounce back and the travel time of the returning sound, or “ping,” is measured to create bathymetric charts of the seafloor.

“It sends out multiple pings at the same time and they’re all angled differently, so you have a full swath of the area,” said Ms. Barnes.

The overall speed of sound is also measured using sensors, known as expendable bathythermographs (XBTs), to ensure accurate data collection from the multibeam sonar.

The resulting seafloor maps help survey teams locate interesting features, such as hydrothermal vents, rock cliffs and ridges, that can be further explored using remotely operated vehicles (ROVs) equipped with cameras.

Eastern Edge

Earlier in the summer, Ms. Barnes joined the crew of the RV Kilo Moana in Seattle, Wash., where she had participated in an international remotely operated vehicle (ROV) competition with the Eastern Edge Robotics team.

Eastern Edge placed eighth among the 28 Explorer class teams at the Marine Advanced Technology Education (MATE) ROV International Competition. As the team’s chief executive officer, she’s optimistic about the team’s chances in 2019.

“This year is our comeback year,” she said.

The Eastern Edge team consists of 20 post-secondary students from a variety of backgrounds, including ROV technology, ocean mapping, business, engineering and computer science.

Kilo Moana expedition

Her month on board the Kilo Moana, which is operated by the University of Hawaii, was spent mapping the seafloor in the Gulf of Alaska.

As a watchstander on the night shift, she watched the data as it came in to ensure accuracy. She also created sound-velocity profiles of the water column by casting XBTs into the ocean every six hours, or more, to measure water temperature and depth. If the water temperature readings change frequently, more XBTs are deployed.

“The reason we do that is because the speed of sound gives you the depth,” she said. “We know the frequency of our sonar, and if we know the speed that it’s travelling to the bottom, then we can figure out how deep the water depth is.”

These devices also play an important role in collecting accurate water depth measurements during multibeam mapping operations. Information from the XBTs is used to adjust the multibeam sonar mapping system to ensure the data it collects is accurate.

Sharing the experience

This semester, Ms. Barnes will have opportunities to share her summer experiences at sea during talks she’ll give to first-year and second-year ocean mapping students.

Her message?

“Ocean mapping is cool – it’s the best program,” she said only half-jokingly. “I made the right choice.”