Seiches induced by storms in the English Channel

Investigation of an extreme storm surge event revealed the presence of an oscillation in sea level with a period of 2–6 h. The English Channel is well known for its quarter- and sixth-diurnal tides, and it was expected that these oscillations were simply the result of tide-surge interactions. However, results of model experiments permitted the reproduction of oscillations from wind forcing alone. The forcing used was from an extreme wind event in December 1989. In this article we describe these oscillations, and in particular their spatial characteristics. It is shown that the dominant response is a transverse mode of the English Channel, with minimum amplitude in the central Channel and maximum amplitude in the Baie de Seine and the Golfe de St Malo.