File:Sediment Swirls in Lake Erie (MODIS 2024-02-21).jpg

English: A historically low ice season across the Great Lakes left Lake Erie completely ice-free by February 15, 2024. Howling winds associated with an intense mid-February winter storm churned the exposed surface, stirring sediment from the bottom of the shallow lake. The winds, combined with run-off from snow and rain, also directly delivered sediment into Lake Erie. This also filled local rivers, which then poured their mud-laden waters into the lake.

By February 19, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite acquired this true-color image, Lake Erie's waters were widely stained by muddy, sediment-laden swirls. Sediment was particularly thick in the west and along the northern shoreline. Milky green, light blue, and pale tan tones are also likely caused by floating sediment.

As the shallowest of the Great Lakes, Lake Erie’s bottom can easily be stirred up by intense winds and the currents generated by winds or river inflow. The lake bottom is rich in quartz sand and silt, as well as pale-colored calcium carbonate (chalk) from limestone. Some of the green may also come from phytoplankton, which are microscopic plant-like organisms that often bloom in the lake when conditions are favorable. Sediment and chemicals carried into the lake by run-off contains nutrients that can spur the growth of phytoplankton.

The small Lake St. Clair, located north of the western section of Lake Erie, also contained heavy sediment. The mud-filled southern half of that lake appeared so tan that it almost blends into the surrounding tan landscape.