Human-manned vehicle Alvin successfully completes scientific verification

The diver occupied by humans Alvin is ready to return to scientific research at its newly certified maximum depth of 6,500 meters. That’s the conclusion of a team of scientists who have spent the past three weeks taking the sub-icon through its paces at locations in the Puerto Rico Trench and the Middle Cayman Rise, testing its science and engineering systems to make sure that are able to support the requirements. of deep sea sampling and data collection.

“We have set a high standard for Alvin and it easily met or exceeded our expectations,” said Woods Hole Oceanographic Institution (WHOI) Associate Scientist Anna Michel, chief scientist of the national deep diving facility that operates it. Alvin. “Alvin is ready for science.”

Michel and University of Rhode Island geophysicist Adam Soule led the way Alvin’s The Science Verification Expedition, which left San Juan, Puerto Rico, on July 26 and completed five science dives in the Puerto Rico Trench. Those dives focused on the submarine’s ability to support multi-disciplinary research including geological sampling and surveying among high rocks formed by the collision between the North American and Caribbean tectonic plates and biological sampling in the depths of the abyss and hadal Scientists were able to make direct observations and collect samples of exposed oceanic crust, deep channels carved into the Puerto Rican platform, and marine organisms, some of which were the deepest known examples of their species.

Hydrothermal vent and penetration sites

After a short stop in San Juan to exchange scientific crew, Alvin‘s support ship, research ship Atlantis, continued in a region south of the Cayman Islands known as the Cayman Rise, where the two plates are separating at a rate of about 15 millimeters per year. There, scientists conducted nine more dives, focusing on chemical and biological sampling around hydrothermal vents and seeps, including at the Beebe Vent Field—the hottest and deepest known hydrothermal vents on Earth.

“These were complicated dives in complex locations that were a test not only of the submarine, but also of the people who operate it and who make the science possible,” Soule said. “Their skills and recent improvements in sub-meant that we were able to make fundamental new discoveries, while also confirming its operation.”

Exploring deep sea places

The upgrades were funded by the National Science Foundation (NSF), installed during a repair period that began in March 2020, and built on additional upgrades completed in 2014. The most recent round of upgrades included new titanium ballast spheres, hydraulic system improved, new propulsion and engine controllers, updated command and control and navigation systems and a new 4K imaging system. BECAUSE Alvin is owned by the US Navy, it then completed a three-week sea trial in cooperation with the Naval Sea Systems Command (NAVSEA), which oversees the safety of all ships and submarines in the fleet, culminating in the official certification for operated at depths of up to 6500 meters.

In total, Alvin completed 14 dives during the NSF-funded scientific verification expedition for a total of 102 hours submerged, 53 of which were spent exploring the sea floor, a significant feat given the extended time required to reach in places that are up to 2000 meters deeper than those of the submarine. previous maximum depth. In addition, the dives allowed 11 scientists to make their first dives Alvinsomething Michel said was an intentional part of the expedition.

“Alvin it is built and maintained to enable new discoveries and provide new insight into how our planet works,” said Michel. “Each generation of scientists presents new questions and Alvin has been answered in ways that have rewritten the textbooks. There’s a new generation that expects to use sub-sub and we tell them, ‘Alvin it’s ready, where do you want to go?'”