News Release

Lost European delta predicts the future of modern-day rivers

Peer-Reviewed Publication

Netherlands Organization for Scientific Research

Twelve million years ago the Eridanos flowed through what is now the present Baltic Sea, past modern-day Scandinavia, North Poland and Germany, over Denmark and the Netherlands, and into what is now the North Sea Basin. There it formed a giant delta which covered the entire North Sea. About one million years ago during the ice age, land ice destroyed the river and the North Sea and Baltic Sea were formed.

Geologists from Delft reconstructed the deposit patterns of the Eridanos Delta using seismic data. From a ship in the North Sea, geophysicists transmitted sound waves to the sea floor. Hydrophones picked up the echoes from the sound waves. Mathematical processing provided seismic lines, which could be interpolated into maps of the layers that Eridanos deposited. The maps provide insights as to what the course of the river must have been.

By comparing map data with climate data from the last nine million years, the geologists discovered that the climate had influenced the river. During warm, wet climates relatively little settlement reached the river, whereas during cold and dry climates the river had to process much sediment. During such periods the slopes were eroded quickly, as a result of which channels silted up and the course of the river changed.

The research results provided the basis for the development of numerical models, which predict river dynamics over periods of hundreds of years. The models can help to answer questions such as "How will the Netherlands Delta develop as the climate changes?" and "Will climate changes have consequences for nature development projects along our large rivers?"

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The research forms part of the NEESDI project. This is a large cooperative project, financed by the Netherlands Organisation for Scientific Research, between Dutch Earth Science faculties. NEESDI is an acronym for Netherlands Environmental Earth System Dynamics Initiative. The Netherlands Institute of Applied Geosciences (NITG-TNO) provided data.

For further information please contact Irina Overeem (Department of Earth Sciences, Delft University of Technology, now at the Institute for Arctic and Alpine Research in Boulder, Colorado, United States) tel. +1 303 735 0376 (8 hours behind Central European Time), fax +1 303 492 6388, e-mail i_overeem@yahoo.com or irina.overeem@colorado.edu. The defence of the doctoral thesis took place on 18 March 2002. Dr Overeem’s supervisor was Prof. S.B. Kroonenberg.


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