Monomictic lake

Lake Titicaca

Monomictic lakes are holomictic lakes that mix from top to bottom during one mixing period each year. Monomictic lakes may be subdivided into two types:

1. Cold monomictic lakes are lakes that are covered by ice throughout much of the year. During their brief "summer" the surface waters remain at, or below, 4°C. The ice prevents these lakes from mixing in winter. During summer these lakes lack significant thermal stratification, and they mix thoroughly from top to bottom. These lakes are typical of cold climate regions (e.g., much of the arctic).
   
   
2. Warm monomictic lakes are lakes that never freeze, and are thermally stratified throughout much of the year. The density difference between the warm surface waters (the epilimnion) and the colder bottom waters (the hypolimnion) prevents these lakes from mixing in summer. During winter the surface waters cool to a temperature equal to the bottom waters. Lacking significant thermal stratification, these lakes mix thoroughly each winter from top to bottom. These lakes are widely distributed from temperate to tropical climatic regions. One example is South Australia's Blue Lake, where the change in circulation is signaled by a striking change in colour.

Examples of monomictic lakes

• Dal Lake
• Mono Lake - prior to 1941 water diversions
• Sea of Galilee
• Lake Titicaca
• Issyk Kul Lake
• Okanagan Lake
• Lake Turkana
• Blue Lake (South Australia)
• Hartbeespoort Dam
• Lake Kasumigaura
• Lake Sélingué
• Manasbal Lake
• Roodeplaat Dam

See also

• Thermocline