Seneca Lake

The US Navy tests the sonar for America’s nuclear submarines in Finger Lakes wine country, from instrumented barges permanently moored over the deepest part of Seneca Lake at Dresden, New York, where a 220-ton derrick crane lowers full-size sonar domes into water up to 600 feet deep. The lake earned the assignment: a glacial trough gouged so far into an ancient river valley that its floor lies below sea level, 616 feet down at its deepest, running about 38 miles from Geneva to Watkins Glen. It also booms. The unexplained sounds, known locally as the Seneca Guns or Lake Drums, got a James Fenimore Cooper short story in 1851 and still have no settled explanation.

The depth contours show the classic Finger Lakes profile at its most extreme. The map traces long, tightly parallel lines running the length of both shores, where the lakebed plunges toward a deep, flat central trench that goes on for miles. Only at the two ends do the contours relax into shallow shelves. It is glacial carving reduced to its purest form: one long, deep cut.