Research Vessel Sally Ride Makes One Of First Scientific Voyages
Editor's note: Headline has been updated for clarification purposes.
Monday, December 19, 2016
The ship wrapped up its first official journey Thursday. The cruise was short, just three days. But it was a beginning.
The surface of the ocean is vast and mostly featureless, but scientists know there is a universe of knowledge to be discovered under the sea. They hope researchers at UC San Diego's Scripps Institution of Oceanography continue to lead the way like they did on the ship's first official scientific journey.
Researchers set out to recover underwater moorings during this trip. The devices were dropped into the ocean months ago.
Recovery is essential to collect the scientific data.
Once the ship is close, a release code is sent to the mooring. The weights holding the instrument underwater are released and the device floats to the surface. From there, it's a matter of grabbing the array and hauling it back on board.
The journey's principal investigator is a UC San Diego graduate student. Maddie Hamann stands by one of the instruments that's been underwater, collecting data, for months. The huge orange ball is a floatation device that keeps the small, acoustic instruments pointed down.
Underwater instruments capture data
"It sends out acoustic pings and by measuring the Doppler shift between the outgoing sound and the incoming sound wave. You get information about what the velocity of the water is," Hamann said.
She is studying how underwater tides flow through the La Jolla Canyon system. That movement creates turbulence which brings nutrients to vibrant nearshore areas.
"They're kind of a connection between the offshore waters and the nearshore waters," Hamann said.
Knowing how that complex underwater system works could help researchers understand how the currents create and maintain healthy marine environments near the coast.
But underwater tides aren't the only target on this research cruise.
UC San Diego researcher Ana Sirovic is also retrieving moorings that have been recording underwater sounds for months. She is not listening for water, but for the large mammals that live in it.
"The species that we're interested in are endangered species," Sirovic said. "Large baleen whales, like blue and fin whales, and their populations in Southern California, some of them have been steady for a long time they don't seem to be recovering after the whaling that happened in the 20th century."
Sirovic is using acoustic recorders to track whales that move through the region and she is tracking schools of plankton and krill. Track the food, she reasons, and you can track what eats it. The research vessel makes that work possible.
"We deploy the instruments on the floor of the ocean for months at a time and we come back to retrieve them just on this trip and so they have been collecting data for the last four months," Sirovic said.
The physical oceanography of deep tidal phenomena doesn't seem to be related to bioacoustic recordings of animals, but being on the ship together has Sirovic and Hamann thinking about ways to work together.
"We decided next time we all deploy moorings we should talk and figure out ways to collaborate and put their instruments on our mooring and our instruments on their mooring so we can collect data over larger areas," Sirovic said.
This cruise was short, but future cruises could last a couple of months. The Sally Ride is big enough to carry several dozen researchers and technicians which means it’s large, but the ship is really a lesson in perspective.
The ship is still being tested
"Yeah, you're tiny when you're out here," said Keith Shadle, a marine research technician.
Collecting moorings and doing underwater recordings from the ship are pretty easy and routine. However, the crew is still trying to figure out all of Sally Ride's capabilities. One upcoming project will determine whether the ship can take core samples from ocean floor.
"We're going to tilt this big huge tube, maybe about 20 feet long. Vertical in the water," Shadle said.
They add weights and release it so it rushes to the bottom of the ocean.
"The idea is for it to hit, fall and collect a big sample of the bottom of the ocean," Shadle said.
This voyage is the first of what researchers hope will be many ocean journeys.
The Sally Ride is designed to have a lifespan of more than 40 years likely allowing it to touch all of the world's oceans before it retires.
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