 deployed their benthic rover off the coast of central California this summer to test its ability to record oxygen levels in the underwater sediment and document the effects of climate change on marine life as the oceans warm.)
IN DEEP: Researchers at the Monterey Bay Aquarium Research Institute (MBARI) deployed their benthic rover off the coast of central California this summer to test its ability to record oxygen levels in the underwater sediment and document the effects of climate change on marine life as the oceans warm.
Image: © MBARI
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While the Spirit and Opportunity rovers this summer soldiered on after more than five years on Mars (despite a number of glitches), an intrepid bot called the benthic rover created by scientists at the Monterey Bay Aquarium Research Institute (MBARI) showed its chops as a remote research vehicle by spending most of July traveling over the Pacific Ocean floor about 40 kilometers off the California coast, some 900 meters below sea level.
Robotic voyagers today give scientists the ability to continuously study remote places and phenomena previously available only in snapshots. MBARI's rover afforded researchers a close-up view of life on the deep seafloor, collecting information they're hoping will help document the effects of climate change on marine life as the oceans warm. The aquatic roamer took 18 different measurements (each one taking about a day to complete) of how much oxygen is being consumed by the community of organisms living in the ocean floor's sediment. From there, scientists hope to calculate how much food the creatures are consuming.
Although researchers are still analyzing the oxygen figures, MBARI marine biologist Ken Smith says the fact that the scientists now have so much data to work with proves the rover performed well.
Smith has been developing the benthic rover with MBARI project engineer Alana Sherman over the past four years. They designed it to creep slowly across the seabed at a rate of one meter per minute, stopping every three to five meters to examine the sediment and organisms in its path. One of the researchers' goals is to determine how deep-sea animals find enough particles of organic detritus, known as "marine snow," for sustenance in the absence of plant life.
The rover uses probes to record oxygen levels in the underwater sediment as well as acoustic scanners to sense the presence of worms and other animals as deep as 10 centimeters into the mud.
The researchers shielded the rover's electronics and batteries inside titanium pressure spheres so the vehicle could withstand 420 kilograms per square meter of water pressure. Another important feature are the large yellow blocks of buoyant foam attached to the vehicle that help support much of its 1,400-kilogram weight (making it weigh only 45 kilograms underwater) so that its tractorlike treads do not get bogged down on the seafloor.
To avoid the problem of loose sediment affecting the rover's measuring equipment, the researchers programmed the device to sense the direction of the prevailing current, and move only in an up-current direction, so that any stirred-up mud and particles would be carried away from the front of the vehicle.
During its July mission, the rover was tethered via a long cable to the Monterey Accelerated Research System (MARS) Ocean Observatory Test Bed. This provided the vehicle with power and a communications link, although the goal is to make the rover battery-operated and autonomous by year-end. "We used a cable this time so we could troubleshoot any problems," Smith says.
Once the rover is autonomous, it will store data for six months on its own. "You'll throw it off the ship, and then you send an acoustic signal demanding it to drop its weights when you want to retrieve it," Smith says. The researchers are planning at some point to outfit the rover with an acoustic modem so it can communicate information in real-time with buoys, which can then relay messages to researchers on board ships or onshore.
The rover's next mission will be to continue measuring sediment samples at its underwater stomping ground in Monterey Bay for two and a half months this fall. In 2010 the researchers plan to increase the stakes, sending their creation on a six-month crawl of the ocean floor 220 kilometers off the central California coast at a depth of about 4,000 meters (its depth limit is 6,000 meters). Success in these endeavors could see the rover sent to study the seabed near Antarctica or hooked up to a deep-water observatory several hundred kilometers off the coast of Washington State.
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7 Comments
Add Comment...so the vehicle could withstand 420 kilograms per square meter of water pressure.
Reply | Report Abuse | Link to thisPosted above without finishing. I can't figure out what the author meant to type, but surly the rover can dive deeper than 40cm. Why don't you use standard units like Pa or PSI?
Reply | Report Abuse | Link to thisBefore the benthic rover can find signs of global warming, wouldn't the scientists running this study need a baseline data set? If you can't say what "normal" is, how can you determine what changes have occurred?
Reply | Report Abuse | Link to thisOne other point: What, exactly is the "normal" climate of the Earth? Paleoclimatology has demonstrated that the only thing about the climate that never changes is that it is always changing. If Nature can't pick a "normal" climate, how can we?
Zoo and Aquarium Visitor .
Reply | Report Abuse | Link to thishttp://www.zandavisitor.com .
Great place for zoo and aquarium visitors.
There needs to be a comprehensive study of the Ocean ridges and the deep sea vents. Included in this study by using this vehicle, we must explore the bottom depths of great trenches. Mathematical extrapolations cannot tell the story of the green house gases these features emit. They could be pooring huge amounts of gases into the sea and atmosphere. We haven't taken a serious look. Our views of other moons and planets in the solar system show amazing volcanic and tectonic splits and shifts. The same could easilly be happening below our seas without our knowledge. It could be disturbing methane hydrate causing fluctuations in the methane in the atmosphere that currently not fully explained. It could show that it may not be mankind that is influencing the climate as much as some of the blame man first crowd would like to believe. By doing the research, it will show definitive answers not based on extrapolation and it will show if also have to make focus on removal of gases to keep the planet climate habitable to humans.
Reply | Report Abuse | Link to thisRon Heeren
The rover needs to explore more than just near coast. Research needs to be directed to the mid-ocean ridges and the deep sea trenches. We do not know exactly how much greenhouse gases these are producing. Like other bodies in the solar system, tectonics could be creating more havoc and gases than mathematics currently thoerizes. It could explain anomolies in the methane amounts in the atmosphere through potential disruptions of great layers of hydrates on the Ocean floor. We cannot legitimately conclude that people are the sole cause of why our climate is currently changing until we study the ocean floors, ridges, and trenches in depth. It may be that we might have to change our focus on removal planet and man produced gases rather than on withholding them only.
Reply | Report Abuse | Link to thisRon Heeren
We need to optimise the design and build a fleet of these rovers. By the way the design pressure should probably read 420 kg/square centimeter and that would give it a safety factor of about 4. The way to design the sensitive parts like battery and electronics containers would be to install them in a silicone oil or gel environment to prevent the water from reaching them, but still allow the full pressure to reach them. water tight casings are very difficult to guarantee, especially when there have to be penetrations for cables etc.
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