Mean depth can be a more useful indicator than maximum depth for many ecological purposes. Unfortunately, accurate mean depth figures are only available for well-studied lakes, as they must be calculated by dividing the lake's volume by its surface area. A reliable volume figure requires a
bathymetric survey. Therefore, mean depth figures are not available for many deep lakes in remote locations. The average lake on Earth has the mean depth 41.8 meters (137.14 feet) The
Caspian Sea ranks much further down the list on mean depth, as it has a large
continental shelf (significantly larger than the oceanic basin that contains its greatest depths). Of the 129 registered lakes; 69 are known to be
cryptodepressions. These include:
Vostok{{cite news |publisher=The Conversation |title=What Lies Beneath Antarctica's Ice? Lakes, Life and the Grandest of Canyons |url=http://theconversation.com/what-lies-beneath-antarcticas-ice-lakes-life-and-the-grandest-of-canyons-61748 |date=July 17, 2016 |first1=Christine |last1=Dow This list contains all lakes whose mean depth is reliably known to exceed 100 metres (328 ft). The following table uses the template to permit sorting of numeric values. Without this approach a value of 101 meters would sort higher than 1000 meters. Example: To enter a cell value of 923 meters, place in the meters column. To enter a value that includes non-numeric characters, use the template; this allows you to specify a sort value that does not exactly match the text displayed. Example: To enter a cell value of >900 meters, place >900 in the meters column. See
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Template:ntsh --> ==Greatest maximum depth by continent==