Introduction to Lake Erie Sample Clauses

Introduction to Lake Erie. The physical characteristics of Lake Erie have a direct bearing on how the lake ecosystem reacts to various stressors. By volume it is the smallest of the Great Lakes, and next to smallest in surface area. As the shallowest of the Great Lakes, it warms quickly in the spring and summer and cools quickly in the fall. During long, cold xxxxxxx, a large percentage of Lake Erie is covered with ice, and occasionally it freezes over completely. Conversely, in warmer years, there may be no ice at all. The shallowness of the basin and the warmer temperatures make it the most biologically productive of the Great Lakes. Lake Erie is naturally divided into three basins (Figure 2.1). The western basin is very shallow with an average depth of 7.4 metres (24 ft.) and a maximum depth of only 19 metres (62 ft.). The central basin is quite uniform in depth, with the average depth being 18.3 metres (60 ft.) and a maximum depth of 25 metres (82 ft.). The eastern basin is the deepest of the three with an average depth of 25 metres (82 ft.) and a maximum depth of 64 metres (210 ft.). The central and eastern basins thermally stratify every year, but stratification in the shallow western basin is rare and very brief, if it does occur. Stratification impacts the internal dynamics of the lake, physically, biologically and chemically. These physical characteristics cause the lake to function as virtually three separate lakes. Lake Erie’s long narrow orientation parallels the direction of the prevailing southwest winds. Strong southwest winds and strong northeast winds set up extreme seiches, creating a difference in water depth as high as 4.3 metres (14 ft.) between Toledo and Buffalo (Xxxxxxx, 1979). The effect is most spectacular in the western basin where large areas of the lake bottom are exposed when water is sloshed to the northeast, or large areas of shoreline are flooded as water is sloshed to the southwest. Overall current and wave patterns in Lake Erie are complex, highly changeable and often related to wind direction (Bolsenga and Herdendorf, 1993). Eighty percent of Lake Erie’s total inflow of water comes through the Detroit River. Eleven percent is from precipitation. The remaining nine percent comes from the other tributaries flowing directly into the lake from Michigan, Ohio, Pennsylvania, New York and Ontario (Bolsenga and Herdendorf, 1993). The Niagara River is the main outflow from the lake. About one-third of the total population of the Great Lakes basin resides w...