Tertius (sandbank)

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Tertius (also known as ''Tertiussand'') is a sandbank located in the

Heligoland Bight The Heligoland Bight, also known as Helgoland Bight, (german: Helgoländer Bucht) is a bay which forms the southern part of the German Bight, itself a bay of the North Sea, located at the mouth of the Elbe river. The Heligoland Bight extends f ...

off the coast of

Dithmarschen Dithmarschen (, Low Saxon: ; archaic English: ''Ditmarsh''; da, Ditmarsken; la, label=Medieval Latin, Tedmarsgo) is a district in Schleswig-Holstein, Germany. It is bounded by (from the north and clockwise) the districts of Nordfriesland, Schle ...

belonging to the

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

state of

Schleswig-Holstein Schleswig-Holstein (; da, Slesvig-Holsten; nds, Sleswig-Holsteen; frr, Slaswik-Holstiinj) is the northernmost of the 16 states of Germany, comprising most of the historical duchy of Holstein and the southern part of the former Duchy of Sc ...

. Formerly a ''Hochsand'' (a sandbank rising above the

ordinary high water mark A high water mark is a point that represents the maximum rise of a body of water over land. Such a mark is often the result of a flood, but high water marks may reflect an all-time high, an annual high (highest level to which water rose that ...

, effectively an island), Tertius has been reduced in elevation by

coastal erosion Coastal erosion is the loss or displacement of land, or the long-term removal of sediment and rocks along the coastline due to the action of waves, currents, tides, wind-driven water, waterborne ice, or other impacts of storms. The landwa ...

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. Tertius seehundbank vor buesum 22

Tertius lies about 10 km west of the popular tourist destination of

Büsum Büsum () is a fishing and tourist town in the district of Dithmarschen, in Schleswig-Holstein, Germany. It is situated on the North Sea coast, approx. 18 km southwest of Heide. Büsum is also the administrative seat of the ''Amt'' ("collec ...

in the

Meldorf Bay The Bay of Meldorf

, bordering the tidal channel '' Piep'', which serves as the access waterway to the port of Büsum. To the south lies the island of

Trischen is an uninhabited island in the Meldorf Bay, about off the North Sea coast of Dithmarschen in north Germany – about from the ''Trischendamm'' embankment. The island belongs to the municipality of Friedrichskoog and is only occupied from ...

, and to the northeast lies the ''Hochsand'' of

Blauort Blauort is one of Germany's uninhabited North Sea sandy islets off the coast of Dithmarschen (near Büsum), and measures about 1,200 m from north to south and 500 metres from east to west. It is surrounded by the sandbank of ''Blauortsand'', whic ...

. According to the Schleswig-Holstein National Park Office in

Tönning Tönning (German; Low German ''Tünn'', ''Tönn'' or ''Tönnen''; Danish: ''Tønning''; North Frisian: ''Taning'') is a town in the district of Nordfriesland in the German state of Schleswig-Holstein. History Tönning was destroyed in the ...

, Tertius, like Blauort, belongs to the parish of Hedwigenkoog in the district of

. However, the state government of Schleswig-Holstein has not yet officially confirmed and authorised this, so the sandbank technically remains an unorganised location. Tertius, when not submerged, provides a resting ground for seabirds and seals. Sightseeing tours are sometimes organised from Büsum to observe these animals. Though the sandbank is not part of the highly protected Zone 1 of the

Schleswig-Holstein Wadden Sea National Park The Schleswig-Holstein Wadden Sea National Park (german: Nationalpark Schleswig-Holsteinisches Wattenmeer) is a national park in the Schleswig-Holstein area of the German Wadden Sea. It was founded by the Parliament of Schleswig-Holstein on 1 O ...

, public access to Tertius is subject to restrictions. The only man-made structure on the island is a

daymark A daymark is a navigational aid for sailors and pilots, distinctively marked to maximize its visibility in daylight. The word is also used in a more specific, technical sense to refer to a signboard or daytime identifier that is attached to ...

, which serves as an optical navigational aid for ships. Frisian Islands Dithmarschen Wadden Sea Sandbanks of the North Sea Landforms of Germany {{SchleswigHolstein-geo-stub