The bottom substrate (sediments) that provides a habitat for burrowing organisms. 2. Physical and Chemical Dynamics

Most natural lakes in North America were formed by glaciers, though Maryland, for example, is notably missing natural lakes because it was never glaciated.

Deep lakes often form a three-layered structure in summer: a warm upper layer ( epilimnion ), a middle transition layer ( metalimnion ), and a cold bottom layer ( hypolimnion ).

Lakes are often temporary features on a geological timescale, created by glacial, tectonic, or volcanic processes, and eventually filled in by sedimentation.

The shallow area near the shore where sunlight reaches the bottom, allowing for rooted aquatic plant growth (macrophytes).

A new dataset offers detailed 3D bathymetry for 510,530 global lakes, representing 98.9% of global surface water storage. Lakes and Reservoirs | U.S. Geological Survey - USGS.gov