Survey Vessel Thomas Jefferson Returns to Map More of Lake Erie

CLEVELAND, OH — A survey ship that visited the Great Lakes for the first time four years ago is back to map areas that haven’t been surveyed in decades. The NOAA ship Thomas Jefferson entered the St. Lawrence Seaway in April on its way to Cleveland, Ohio for a new mission to map parts of Lake Erie and Lake Ontario.The survey will update nautical charts, improve navigation safety and collect lakebed data that can also help scientists identify habitats, model storm surge and better understand the underwater landscape.

NOAA says western Lake Erie is one of the shallowest and most heavily trafficked areas in the Great Lakes system, but some areas targeted this year have not been surveyed in more than 80 years. The Great Lakes are the least-mapped region of the United States, according to NOAA. Only about 17 percent of the lakes have been mapped with modern methods. Weather, currents, ice, debris and wrecks can change underwater conditions, making old charts increasingly unreliable.

The Jefferson is a 208-foot hydrographic survey ship based in Norfolk, Virginia. It uses multibeam sonar to create detailed images of the lakebed. The work is often described as “mowing the lawn,” with survey vessels running back and forth in a grid pattern. The ship’s return follows its 2022 Great Lakes visit, during which it surveyed 450 square nautical miles of Lake Erie and 274 square nautical miles of Lake Ontario. That work identified 42 confirmed and new shipwrecks and 22 additional lakebed features.

Read more at this MLive link.