08/12/2026
There is a 3-mile-wide underwater channel connecting Lake Erie’s central and eastern basins, and strong eastbound winds can send deep water rushing west through it.
The Pennsylvania Channel runs between the Pennsylvania shoreline and the Long Point-Erie Ridge, a large submerged glacial moraine that stretches across most of the lake between the two basins.
The moraine forms an underwater barrier between the relatively shallow Central Basin and the much deeper Eastern Basin. The Pennsylvania Channel, about 3 miles wide and 75 feet deep, provides the main deep-water pathway between them.
Strong winds blowing east along Lake Erie can push enormous amounts of surface water toward Buffalo. Water levels rise in the east and fall in the west, sometimes by several feet. When the wind weakens or changes, water also sloshes back west across the surface. These back-and-forth movements of water are called seiches.
But during these strong eastbound wind events, some water is already moving in the opposite direction below the surface.
Deep water flows west through the Pennsylvania Channel toward the Central Basin. The current can be strong enough to carry sediment, helping build what appears to be a natural levee along the northern side of the channel.
So during strong eastbound winds, Lake Erie can be moving in two directions at once: surface water pushed east by the wind while deep water flows west through a channel hidden beneath the lake.
Image: NOAA