Undersea survey will shed new light on coastal erosion

The bathymetric survey, which started in January, is examining the terrain and contours of land under the sea and so far has covered three-quarters of the East Riding’s coastline.

Coastal engineer Neil McLachlan from East Riding Council said: “The beach is just a narrow strip and most of the sand movements are occurring under the sea, so this will give us a much better picture of what’s actually happening along the coast.

“Some people have said our erosion is partly caused by dredging which occurs some distance offshore. Our view is that it isn’t, but this survey will give us a much clearer picture.

“If we can show there are some sandbanks offshore and they have stayed there and there are healthy supplies of sand offshore it must be something that’s just happening at the cliff face.”

The survey is carried out using sound pulses which are transmitted and collected by a survey vessel as it repeatedly travels up and down the coastline. The on-board equipment uses the time the sound beam takes to return to calculate the seabed distance and, as the number of passes increases, a complete picture of the seabed is produced.

The work is being supervised for the council by Pell Frischmann, a national consultancy firm, and carried out by NetSurvey Ltd, a specialist seabed survey company. The results will be used to update the Hydrographic Office’s charts of the area.