We know that rivers transport silt and sediment, but it’s not every day that we get a bird’s eye view of just how much. My colleague John Trotti, the editor of MSW Management and Grading & Excavation Contractor, sent me this photo of the Connecticut River taken a week and a half ago, on September 2, from the Landsat 5 satellite. The photo shows the river spewing a huge plume of sediment into Long Island Sound. The river, as the caption notes, drains nearly 11,000 square miles in Vermont, New Hampshire, Massachusetts, and Connecticut.
The unusual amount of sediment was the result of Hurricane Irene, which hit the area on August 27, bringing heavy rainfall and record floods. In some areas, the river had 64 times its usual flow—the highest flow rate in more than a quarter century.
The Thames River, to the right of the Connecticut River in the photo, shows much less sediment discharge to Long Island Sound—partly because less rain fell in the Thames watershed, and partly, according to geologists, because the drainage area consists largely of bedrock and has less sediment to lose.