Tsunami - a study regarding the North Sea coast
Bork, I.; Dick, S.; Kleine, E.; Müller - Navara, S. (2007). Tsunami - a study regarding the North Sea coast. Berichte des Bundesamtes für Seeschiffahrt und Hydrographie, 41. Bundesamt für Seeschifffahrt und Hydrographie (BSH): Hamburg, Rostock. 77 pp. Part of: Berichte des Bundesamtes für Seeschiffahrt und Hydrographie. ISSN 0946-6010, more |
| Authors | | Top | - Bork, I.
- Dick, S.
- Kleine, E.
- Müller - Navara, S.
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| Abstract | North Sea storm surges with water levels of 4 to 5 m NN (German ordnance datum) are annually recurring events that are dealt with by the official prediction services. The subject of this study is the behaviour of a hypothetical tsunami of comparable height traversing a wide, shallow shelf. The period of a tsunami ranges between that of wind waves and that of thesemidiurnal tide dominating in the North Sea. Analytical wave theories, which have been developed for sea and swell, do not describe tsunami completely. Numerical models used to forecast storm surges are suitable in principle to simulate the propagation of medium-length waves in the North Sea. This mainly requires an adaptation of grid spacing to the shorterwave lengths. As an example, the propagation of three positive signals with a period of 1800 s, which is typical of tsunami caused by slope failure, and wave heights of 5 to 8 m, has been simulated. Models of this type have limited applicability on the continental slope and are not suitable for near-shore areas. Despite all restrictions regarding the analytical estimations and numerical simulations used, the conclusion appears justified that significantly less wave energy would be present in the German Bight after a hypothetical tsunami has crossed the wide and shallow shelf of the North Sea than be the case on a coast with a steep, narrow shelf that was hit by a comparable tsunami. |
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