©2010 Elsevier, Inc. Chapter 7 Lakes and Reservoirs: Physiography Dodds & Whiles

©2010 Elsevier, Inc. FIGURE 7.1 Satellite images of the Great Lakes (A) and Smithville Reservoir (Missouri) (B). The reservoir is 16 km long. Note the dendritic pattern of the reservoir and the relatively smooth shorelines of the glacially formed Great Lakes. The numerous black dots around the reservoir are farm ponds. (Images from the US Geological Survey)

©2010 Elsevier, Inc. FIGURE 7.2 Global numbers and total areas of lakes by surface area size class. (Data from Meybeck, 1995).

©2010 Elsevier, Inc. FIGURE 7.3 Diagrams of two modes of lake formation associated with tectonic processes. (A) Graben, a block drops below two others. (B) Horst, blocks tip and a lake forms along a single fault line.

©2010 Elsevier, Inc. FIGURE 7.4 Global numbers and total areas of lakes of different geological origins by surface area size class. (Data from Meybeck, 1995).

©2010 Elsevier, Inc. FIGURE 7.5 Cross section of Lake Baikal, the south basin, in the region of maximum depth (1637 m). (Redrawn from Belt, 1992; and Mats, 1993).

©2010 Elsevier, Inc. FIGURE 7.6 Earthquake Lake forming after a large earthquake in 1959 in Montana caused a massive landslide damming the Madison River. This picture taken before the lake was full shows debris still in the water. (Image courtesy of the US Geological Survey).

©2010 Elsevier, Inc. FIGURE 7.7 Formation of some types of glacial lakes. (A) A cross section of a glacier moving down a valley. (B) After the glacier has retreated, it leaves cirque, moraine dammed, and pothole lakes. (Drawn by Sarah Blair).

©2010 Elsevier, Inc. FIGURE 7.8 Paternoster lakes (a string of glacial lakes) in a snowy mountain valley in the Cascades, Skymo Lake. (Photograph courtesy of the US National Park Service).

©2010 Elsevier, Inc. FIGURE 7.9 Bathymetric maps of Belton Reservoir, Texas (left), and Flathead Lake, Montana (right). The reservoir is dendritic and shallow, with the deepest portion near the dam (lower right). Flathead Lake was formed by a combination of tectonic and glacial processes and is deep with a regular shoreline and shallow outlet (lower left).

©2010 Elsevier, Inc. FIGURE 7.10 (Top) A depth contour plot of lake temperature over the course of a year in a dimictic cold-temperate lake (Esthwaite Water, an English lake). The thick black line at the top right corner of contour plot indicates ice cover. (Bottom) Two-dimensional representations of the temperature versus depth at each phase of stratification. (Data from Mortimer, 1941).

©2010 Elsevier, Inc. FIGURE 7.11 Temperature as a function of depth for Triangle Lake, Oregon, on October 1, 1983, and positions of epilimnion, metalimnion, and hypolimnion. (Data from R. W. Castenholz).

©2010 Elsevier, Inc. FIGURE 7.12 Stability of the thermocline in Linsley Pond, Connecticut, before and after a hurricane on September 21, 1938, with wind speeds up to 100 km h 21. (From G. E. Hutchinson, A Treatise on Limnology, Vol. 1, Geography, Physics and Chemistry. John Wiley & Sons, Inc., Reprinted by permission of John Wiley & Sons, Inc.).

©2010 Elsevier, Inc. FIGURE 7.13 (A)A simple water sampler made from a weighted bottle and stopper; (B) a sampler that collects water from depth by displacing water at the surface; (C) a Kemmerer sampler. Only samplers (such as type C) that close at depth are suitable for collecting dissolved gas samples. (Photograph courtesy of Wildlife Supply Company).

©2010 Elsevier, Inc. FIGURE 7.14 An Ekman grab sampler for sampling sediments from the bottom of a lake. These types of grab or dredge samplers come in a variety of shapes and sizes. Most have a spring-loaded trigger (visible on the top of the sampler), which is tripped by a messenger (cylindrical weight on the rope) that is sent down the attached rope; when the messenger trips the trigger, the sampler snaps shut around a parcel of sediment. (Photograph by S. Peterson).

©2010 Elsevier, Inc. FIGURE 7.15 How fetch of an irregularly shaped lake varies with wind direction (A, B) and relationship between maximum wave height and fetch (C). (Equation for C from Wetzel, 1983).

©2010 Elsevier, Inc. FIGURE 7.16 Langmuir circulation cells on a lake. Note zones of convergence where spiral currents meet and go down into the lake. (Image by Pete Else).

©2010 Elsevier, Inc. FIGURE 7.17 Formation of an internal seiche and entrainment associated with wind. Dashed arrows show water flow. (A) The lake under calm conditions; (B) the wind deepens the epilimnion on the right; (C) a strong wind mixes some of the epilimnion with the hypolimnion; (D) the wind stops and the hypolimnion begins to oscillate; and (E and F) the amplitude of the seiche diminishes over time.