The engineers talked about using a robot tank to study the seabed and the carbon cycle. An article about this was published in Science Robotics.
Benthic Rover II (BR-II) was developed by the University of California, San Diego. This is an autonomous two-track mechanism that takes photos and videos, measures the temperature of bottom water, oxygen concentration, flow rate and oxygen consumption by bottom inhabitants. Its main purpose is to understand how carbonaceous substances are buried and released on the seabed, which is important for studying global climate change, since carbon dioxide is considered the main greenhouse gas.
The tracks of the robot tank are made wide to exert the least specific pressure on the ground, and the body of the device, made of titanium and plastic parts, can withstand immersion to a depth of six kilometers. By itself, BR-II has positive buoyancy, but is kept at the bottom by ballast.
If scientists want to return the robot tank, they succeed even if normal communication with the apparatus is completely lost: an acoustic command can be given from the ship, and the ballast will be dropped. In a normal situation, communication is maintained through a float with an antenna, towed by a robot on a cable. The batteries are charged for approximately one year of continuous operation.
The robot was in operation from May 2011 to 2020. The maximum distance covered in one expedition was 1640 meters along the bottom of the Pacific Ocean, several hundred kilometers from California. During its work, the robot has collected a lot of scientific data, among which are some of the most important: on the dynamics of the accumulation of phytodetritis, organic matter formed as a result of phytoplankton deposition on the seabed. It turned out that an increase in the amount of phytodetritis is associated with a decrease in the oxygen concentration in the bottom water. Now scientists have to investigate this relationship and, possibly, improve the model of the Earth’s carbon cycle. In the future, scientists plan to hire a few more robots with different functions to carry out research work.