Calcite precipitation is a phenomenon occuring in most hardwater lakes
world-wide. On May 5th, 1990, a whiting in Lake Constance was observe
d by LANDSAT for the first time. Physical, chemical and biological gro
und data sets prove that the observed structures are caused by calcite
precipitation. This satellite observation provides information about
the patchiness of calcite crystals suspended in the surface water of t
he lake western basin.