• Next meeting: Jour Fixe 16.12.2022
  • Next field campaign: 05.-09.12.2022 

Contact (Spokesperson)

Prof. Dr. Gudrun Massmann
Carl von Ossietzky University of Oldenburg

Funding and duration

Funding: German Research Foundation (DFG)
Duration (1st Phase): 01.04.2021 -31.03.2025

Brief information

Brief information

What is it about?

A wide range of chemical, geological and microbiological processes take place in the sands beneath beaches, about which little is known to date. This dynamic underworld, in which saltwater and freshwater mix and which is termed the "subterranean estuary", is the focus of the research group DynaDeep ("The Dynamic Deep Subsurface of High Energy Beaches"). The German Research Foundation (DFG) is funding the project over four years with up to five million euros.

It is assumed that subterranean estuaries play an important role in the fluxes of nutrients from land to sea and that the dynamic mixing processes in beaches like at Spiekeroog can change this significantly. A better understanding of the subsurface processes in coastal regions therefore helps to advance the protection of our unique coastal ecosystems.

The researchers in DynaDeep hope to find answers to the following questions, among others:

  • How much does the beach change due to individual tides or storm surges?
  • What role do beaches play in the discharge of nutrients into coastal waters?
  • Which microorganisms live in the beach at greater depths and what environmental conditions do they have to deal with?
  • How much is the freshwater lens pushed inland by events such as storm surges?

What do we plan?

The subsurface on the north beach of Spiekeroog will be investigated using interdisciplinary approaches along a line from the foot of the dunes to the low water line - the so-called "investigation transect". This is new territory, because there are hardly any high-resolution investigations of high-energy beaches like Spiekeroog in terms of time and space.

  • Groundwater is extracted at measuring points with pumps and chemically analyzed - partly on site, partly in the laboratory. The results provide information about the composition of the water and the chemical processes taking place. Photo: Stephan Seibert
  • In addition, a crawler drill is used, which enables groundwater samples to be taken at many depths - this results in an even higher-resolution picture of the chemical conditions in the subsurface. Photo: Kai Schwalfenberg
  • Geophysical measurements enable the survey of the subsurface with high spatial resolution – this allows us to reconstruct freshwater and saltwater locations and identify the geological structure beneath the beach. Photo: Gudrun Massmann
  • Changes in the terrain surface - caused by wind and sea – will be recorded by drone flights. A large number of aerial photos enable the creation of a three-dimensional model of the beach. Photo: Jairo Cueto
  • Morphological changes, water levels, wave heights and weather information are recorded by modern sensor systems at the DynaDeep measuring pole - and thus provide information about the dynamics of the beach and the North Sea. Photo: Jairo Cueto

Why Spiekeroog?

There is a lot to be said for the green island of Spiekeroog as a project location. The natural conditions that characterize Spiekeroog make it a so-called "high-energy beach". This means that the energy of the sea in the form of wind and waves makes large and rapid changes to the beach. Those who have regularly visited Spiekeroog may have already noticed that the relief and location of the beach can change significantly from year to year. These are ideal conditions to study the influence of a changing coast on the subsurface processes in a short time. Furthermore, and very importantly, Spiekeroog offers excellent research infrastructure that has proven itself for many years and is what makes research work possible in the first place.

DynaDeep is supported and enabled by:

Who is involved?

The DynaDeep project is divided into six sub-projects. Researchers from different institutes carry out field studies and experimental work together in the sub-projects. Among other things, the knowledge gained is integrated into mathematical models that contribute to a better understanding of the processes in the beach subsurface. The DynaDeep team consists of researchers from the following research institutions:

  • Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven
  • Institute for Biology and Environmental Sciences, University of Oldenburg
  • Institute for Chemistry and Biology of the Sea, University of Oldenburg
  • Institute for Geosciences, University of Kiel
  • Leibniz Institute for Applied Geophysics, Hanover
  • Max Planck Institute for Marine Microbiology, Bremen

Where can I find more information?

  • Information about the DynaDeep team and the project partners can be found here
  • Information on the sub-projects in DynaDeep can be found here
  • Information on the „Subterranean estuary observatory” can be found here
  • Information about activities in DynaDeep can be found here
  • Information about publications in DynaDeep can be found here

You are welcome to contact us during our investigations. We welcome questions and will try to give you an answer if possible.

Also note the announcements in the Spiekerooger event calendar . Our sampling campaigns are usually accompanied by a "walk on the beach" during which a researcher provides closer insights into and around the field investigations in DynaDeep.

(Changed: 11 Nov 2022)