To Sea!

by Erik Olsen  |  March 7, 2018

Today was the first full day of Dive & Discover Expedition 16. We departed Auckland and, after sailing some 18 hours and 340 kilometers (210 miles) northeast, R/V Thomas G. Thompson is positioned on the surface 1500 meters (4,920 feet) over the rim of the Brothers volcano caldera.  It was a day of intense preparation and testing for the big dives ahead.

Everyone is very eager to get going with deployment of the remotely operated vehicle (ROV) Jason, and excited by what we might discover during the expedition, but it is extremely important when operating at sea that everyone first be aware of potential dangers and be ready to act.

Yesterday, in route to the first dive site, the entire science team walked through safety procedures and tried on large, floppy survival suits, stored in each person’s room. The suits are bright orange, over-sized drysuits that cover nearly every exposed inch of a person’s body. They may look silly, but if you fell in the water, they could save your life.

Soon after, chief scientist Anna-Louise Reysenbach and lead scientist Cornel de Ronde briefed the team on our mission, laying out colorful charts that showed the various spots on the volcano where Jason will be sent to take samples, do experiments and shoot video. Dr. De Ronde also showed off a 3D-printed model of the volcano that you can see in the photos above.

The volcano has been extensively mapped during previous expeditions, but one spot on the chart, still poorly mapped, is of particular interest. That is where in January 2017, during a last-minute dive on the northwestern edge of the caldera, another team discovered a series of towering, 20 meter (66 feet) high black smoker hydrothermal chimneys. The scientists at the time, among them Dr. de Ronde, had no idea that the smokers existed, and he says it was almost an afterthought to check out the area. This trip, the team will explore the black smokers more extensively.

Yesterday afternoon, Dr. de Ronde and Fabio Caratori-Tontini of GNS Science in New Zealand along with Maurice Tivey of Woods Hole Oceanographic Institution, prepared five “thermal blankets”—devices that will allow them to measure the amount of heat escaping from the seafloor of the volcano. The devices are made of fabric and bicycle inner tubes that are filled with water that is far saltier (and so denser) than sea water. They are homemade devices, but extremely effective. The addition of lead weights on the heat blankets will hold them firmly to the seafloor, allowing extremely precise thermometers attached to the blankets to give an accurate reading of the temperature of the seafloor.

“This will tell us how hot the magma chamber is that powers the whole system of vents,” says Dr. Caratori-Tontini.

Earlier today, the heat blankets were loaded in boxes and lowered to the seafloor on a system called an elevator. Elevators are submersible platforms that that scientists use to get equipment down to the seafloor and back without using Jason. The elevator deployment went very smoothly.

Now the elevator and the heat blankets and other equipment sit on the seafloor awaiting the deployment of Jason, which is scheduled to take place later tonight.