Tertius is a sandbank located in the Heligoland Bight off the coast of Dithmarschen belonging to the German state of Schleswig-Holstein.
Formerly a Hochsand , Tertius has been reduced in elevation by coastal erosion in recent decades. As a result, the sandbank is frequently submerged and devoid of terrestrial vegetation. Recent satellite images show that Tertius is often even awash at low tide. Like all unprotected islands, Hochsände, and sandbanks off the west coast of Schleswig-Holstein, Tertius is migrating steadily eastwards.
Copyright: CC 3.0