To explain further, what stops lakes from simply seeping into the dirt, and thus vanishing? As a follow up question, what stops water from getting evaporated, and then the clouds move somewhere else and rain, thus depriving the lake of the water it lost?
In: Earth Science
Geologist here. There are at a few basic reasons the water won’t seep into the ground beneath lakes (from what I can remember off the top of my head).
1. Some lakes are a ‘window’ into an aquifer, where subsurface water has collected and sat for thousands of years. This water can be depleted but as long as the incoming water is greater than or equal to the outgoing water it will remain.
2. Soils (or bedrock) that make up most lakes have a low hydraulic conductivity (the rate at which water permeates through). Soils such as clay or glacial till are excellent soils if you wanted to create a lake. (Fun fact: many landfills are lined with specific types of clay for this exact reason so no pollutants will go into the surrounding earth). If you have terrain where water will pool and sufficient rain or streams, it will create a pond or lake.
3. A surface depression with incoming water may create a lake or pond as long as that water flow is enough to keep the water there. Over time dying plants and the deposition of silt and clay can create a hydraulically restrictive later, ie, peat and organic silts and clays.
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