The Chicago skyline is viewed from Lake Michigan in January 2024. (Brian Cassella/Chicago Tribune) By Karina Atkins | [email protected] | Chicago TribunePUBLISHED: December 1, 2024 at 5:00 AM CSTWe know less about the bottom of the Great Lakes than we do about the surface of Mars, according to Jennifer Boehme.The oceanographer is executive director of the Great Lakes Observing System, an Ann Arbor, Michigan-based nonprofit leading a concerted effort to fully map the world’s largest freshwater body from coast to coast, surface to floor.Only 15% of the lakebed has been documented to modern standards, which could have major consequences for coastal communities as climate change makes storms and floods more frequent and severe. Without an understanding of how the depth and contours of the lakebed are shifting, scientists cannot accurately predict how extreme weather will affect natural habitats and built infrastructure.“There are questions that need to be answered about coastal safety for the Great Lakes, but we can’t answer them because basic information is missing,” Boheme said. “For me, it’s very much a safety issue.”The Great Lakes, which nearly 40 million people in the United States and Canada depend on for drinking water, have already taken a beating from climate change. Water levels dropped this fall to the lowest in years, affecting shoreline ecosystems, access to docks and shipping routes.Most of the imaging taken of the Great Lakes is decades old and low resolution. It does not show the pipelines, cables, shipwrecks and boulders that new technologies make visible.Updated, high-resolution imaging has been taken piecemeal over the years, primarily to inform shipping routes and targeted research. When Boehme and her team began their concerted effort in 2019, 12% of the lakes had been mapped to modern standards.They called the initiative Lakebed 2030, intending to complete the project in 2030. But in the last five years, the Great Lakes Observing system has only mapped another 3% of the lakebed.Systematically creating a holistic picture of the lake’s bathymetry — the underwater equivalent of topography — is a massive undertaking. The five Great Lakes have a combined surface area of 94,250 square miles, roughly the size of the United Kingdom. And they vary greatly, with depths ranging from 210 feet in Lake Erie to over 1,300 feet in parts of Lake Superior. If all that water was spread across the contiguous United States, the nation would be evenly submerged in nearly 10 feet of water.The primary roadblock is money. The Great Lakes Observing System estimates mapping all five lakes will cost $200 million. The money would be spent on a combination of advanced sound and light detection technologies over approximately a decade.Ships are docked at the Illinois International Port District facility on the Calumet River at Lake Michigan in 2023 in Chicago. (E. Jason Wambsgans/Chicago Tribune)Halfway to 2030, they’re rethin
Lun. Dic 23rd, 2024
