  Articles and gems - Protecting sandy coasts - Wadden Sea
This is one of the sandy coast pages (first page).
Norderney is one of the Wadden Islands, a string of barrier islands starting with
the Dutch island of Texel in the west, continuing through Germany to Denmark in the east. The
Wadden Sea is the tidal sea between the barrier islands and the mainland. The Wadden Sea
area (Waddengebied) is a unique area of tidal flats of which there is no equivalent
in the world. 8,000 km2 of tidal flats. There is no vegetation, only silence, seals and
birds. Most parts of the area are tide-dominated, but wave-dominated and wind-dominated
areas occur as well.
More information about the Wadden Sea:
Most of today's sandy coasts are the results of a global sea
level rise that started about 15,000 years ago. Although the rapid rise of sea level
ended some 5,000 years ago, there has been a more recent slow rise of several centimeters.
The Wadden Sea also developed as a result of the sea level rise, a combination of
subsidence and eustatic sea level rise. About 10,000 years ago, the local sea level was about
25 meters lower than it is today.
That was the end of the Weichselian glaciation or glacial in what is now western Europe
(What's a glacial?). Almost all water was still tied up
in ice. The Wadden Sea area as a whole (its position)
remained relatively stable since about 6,000 years ago. (Within the Wadden Sea area, change
was and is continuous. It's a highly dynamical area.) Its water depth did
not increase during the past 2000 years, indicating that sedimentation kept up with sea level rise.
A terminal moraine of the earlier Saale glaciation was located relatively close to Norderney.
The cores of three of the North-Frisian islands (Sylt, Föhr and Amrum) are remainders of
that moraine.
The Eemian interglacial followed the Saale. The
Weichsel glaciation came after the Eemian. The melt water of the Weichselian continued to
erode the Pleistocene. This Pleistocene source material was redeposited on the coast as
Holocene sediments, partly as spits connected to the older Pleistocene. Sand dunes later
developed on these spits: the beginning of the Wadden Islands.
The Wadden Islands became more densely populated between roughly 1000 AD and 1200 AD, but
there is little documentation about it. Only the developments since the 15th and 16th century
are sufficiently documented. In the middle ages, much of the Dutch Wadden area and most of
what is now the Dutch province of Noord-Holland was covered in peat. Sphagnum is the
main vegetation in peat areas. A large lake - Flevo Lake - drained into the North Sea. It was
fresh and non-tidal.
After the Dutch started colonizing the peat areas, mostly for agricultural purposes, much
of the Sphagnum died. The areas subsided and became more vulnerable to storms and
waves. The thus increasing area of water surface lead to the development of larger waves.
The inhabitants did build dikes and dams, but most did not help much. By the middle
of the 14th century, about half of the land present at the beginning of the 10th century
had become inundated. Flevo Lake was increasingly influenced by the sea. Two Pleistocene
Islands (Texel and Wieringen) and several small barrier islands remained.
A similar development took place in Germany.
So, humans were a major influence in the development of the Wadden Sea area (the drowning of the peat areas).
Other factors that determine the development of the Wadden Sea area are:
- the tides
- the wind
- the waves
- geology
- biology.
The sandy coast pages:
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Most recent changes to this page:
November 24, 2007
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