Erik Brown, Tom Johnson and colleagues of the University of Minnesota Duluth's Large Lakes Observatory invited friends of the Institute on the Environment aboard the research vessel Blue Heron on Lake Superior recently to showcase research being carried out by the LLO.
The bright yellow device in front of the group is LLO's Webb Research Autonomous Underwater Glider (UAV). The glider measures temperature, conductivity, water clarity, oxygen content, chlorophyll abundance and other water quality parameters. It is the first instrument of this type built specifically for use in freshwater. It propels itself by adjusting its buoyancy and tilt, and glides forwards, stabilized by its wings. It comes to the surface periodically to communicate with scientists back on shore, sending data and receiving new commands.The extreme efficiency of the glider's propulsion system allows the glider to work in the lake for up to 35 days on a single set of batteries.
LLO guests also got a drink of what could be the world's freshest freshwater - a sample of ice-cold water taken from the bottom of the big lake they call Gitche Gumee by another device, the LLO's Seabird 911+ CTD profiler (right). The profiler measures surface-to-bottom profiles of the lake's conductivity, temperature and depth as well other parameters, such as clarity, chlorophyll abundance, and oxygen content. Researchers deploy it off the stern of the ship using a fiber-optic conductive cable, and can monitor its output real-time in the ship's laboratory. In addition, the platform includes 12 bottles that can be triggered to collect subsurface waters at depths the scientists select.
Guests were also treated to a fascinating presentation by Tom about the global work of the Large Lakes Observatory, especially work on Lake Malawi and Lake Tanganyika. They wrapped up the adventure-filled day with dinner at the historic Kitchi Gammi Club in Duluth, which opened in 1883 in the Grand Old Opera House on Superior St.
Why study great lakes? Check out the cover story of the brand new issue of IonE's Momentum magazine for some intriguing answers.
Photos courtesy of Blue Heron ship's cook and ordinary seaman Lisa Sundberg (top) and Chris Mayr (lower)