ALPENA, MI (AP)-- Government researchers are using sonar to map the bottom of portions of Lake Huron.
The Alpena News says the work is underway off Presque Isle County. The National Oceanic and Atmospheric Administration and its partners are operating a vehicle from a mobile lab on shore.
NOAA says researchers hope to discover more shipwrecks in the Thunder Bay National Marine Sanctuary. The marine sanctuary's boundaries were expanded in 2014 to 4,300 square miles. Research coordinator Stephanie Gandulla says only 20% of the lake bottom within the sanctuary has been surveyed.
The public can see the autonomous vehicle Saturday in the Thunder Bay River. The work ends May 17.