The Year 11 visit to Holderness.
We visited the Holderness coastline, Europe’s fastest eroding coastline, on a cold March day this year.
The first place visited was the hamlet of Aldbrough Cliffs, a small cluster of housing with a pub.
Here the natural processes of coastline erosion were taking place and we saw evidence of erosion. The road (and protective railings) were disappearing down the cliffs of soft boulder clay, and a derelict water main (for a house that was no longer there) stuck out of the cliff. A wall was cracking up as it to started to slide into the sea.
Aldbrough cliffs
erosion is moving them away
North cliffs protected by wide beach ^
The south cliffs ^
At Mappleton, just to the north the small village and secondary road had been protected from erosion by the construction of rock armour groynes. These were made of huge blocks of granite that had been imported from Norway.
These huge groynes had slowed the process of longshore drift and built up a wide beach to their north that protected the boulder clay cliffs from erosion. These cliffs are now covered with grasses and other plants.
By contrast, to the south, the cliffs were steep and bare, a product of erosion.
The effect of the groynes was to make the beach narrower and erosion by hydraulic action, hydraulic pressure and abrasion has increased and the land has eroded even more quickly. Destructive waves could easily reach the cliffs. The groynes have stopped the necessary movement of the protective beach sand by longshore drift.
The rock armour groyne ^
The groynes and sea wall
Hornsea is a small holiday town that has prospered for 150 years. The railway that brought the tourists has now closed and trippers come from the Yorkshire industrial towns by car.
To protect the soft boulder clay cliffs that the town has been built on there are a series of traditional sea defences.
Strong, but expensive, concrete sea walls have been built along most of the front. These need periodic maintenance to make sure they are fit for purpose.
To build up the beach a series of wooden groynes have been placed at regular intervals. Like the rock armour groynes of Mappleton they have encouraged more rapid erosion of the cliffs to the south of the resort.
There is also a section of rock armour by a low section of the wall which is close to Hornsea Mere.
As we were leaving the sun came out – what a contrast to the piercing winds of Aldbrough Cliffs.
