11 June 2008

Spurn cycles

Earlier on I mentioned that I’m looking into the phases of the moon and the rhythm of the tides at Spurn. Now I found out that not only the moon is waxing and waning but that Spurn is cyclic as well: "[Spurn] is a fluid feature, it is thought to undergo a life cycle of some 250 years, during which it gets destroyed, is reborn some metres further westward, stabilises, and then is destroyed again."

The story in more detail: Spurn is built by the sands and gravels eroded from the Holderness cliffs. These cliffs north of the peninsula recede about 2 meters per year. The eroded material is transported south by longshore drift. It forms a spit in lee with the coast line.
Later, when the north easterly waves eat further into the coast, Spurn itself becomes exposed and prone to erosion. It seems that the peninsula has been washed away in a cycle of about 250 years. It then reformed west of its former position to keep pace with the erosion of the cliffs.

Another more recent theory by the Institute of Estuarine and Coastal Studies suggests that only the link to the Holderness coast has changed. The tip of Spurn Point is anchored to glacial moraines dumped after the last ice age. So, it should be stable.*

Who knows? Probably Spurn will keep some of its secrets.
(amended 21 July)

*From: 'Sailing the Rails' by H. M. Frost