West Bay’s Cliff Falls Through Time
West Bay’s iconic golden East Cliffs are chiefly made up of Bridport Sands- rocks that formed from layers of sand in the shallow tropical Jurassic seas around 175 million years ago. Each metre of cliff took 20,000 years to form- and at about 43 metres high that means that when you look at the cliffs you are looking at an 860,000 year chunk of time!
Gradually sea levels changed and what was seabed eventually became exposed cliff face. The crumbly sandy rocks are now subject to all the forces of coastal erosion – wind, waves and weather and therefore huge chunks can tumble down dramatically at any time!
These crumbling cliffs have concerned people locally for a long time. We have newspaper reports from the Victorian era onwards:
A serious landslide occurred Bridport Harbour, Sunday morning, rendering the beach impassable. A thousand tons of the cliff are estimated to have fallen. Exeter and Plymouth Gazette Daily Telegrams – Tuesday 31 October 1876
An extensive landslip occurred on Monday East Cliffs, near Bridport. The debris has blocked the beach and promenade, except low water. Shields Daily Gazette – Wednesday 06 July 1881
West Bay sits in a geological fault so that the West Cliffs are of an entirely different age and composition than the East. Here water-resistant Jurassic clays are topped by sandstones which let the water percolate through. Increasing water pressure between the rock types can result in huge landslides meaning the West Cliffs are just as dangerous as the East:
… it is the cliffs of Dorset and East Devon that are most famous for slipping into the sea in huge masses… [At] West Bay, near Bridport, and further west at Charmouth and Lyme Regis, great falls occur from time to time. Owing the formation of the cliff they seldom go down whole but a big piece spills out into the sea, and then slowly but surely more follow until all the loose ground has taken a new position. Hundreds of thousands of tons fell in this manner at West Bay in October 1906, when for several hours long pieces of cliff some 150 yards deep gradually moved forward and down almost noiselessly. Sheffield Weekly Telegraph – Saturday 05 February 1916
Another great fall of cliff has occurred on the Dorset Coast, near Bridport. About 20,000 tons of cliff have fallen. The passage along the beach is completely stopped except at low water. Portsmouth Evening News – Wednesday 06 July 1881
Looking forward, because of the effects of climate change- such as more extreme weather conditions and rising sea levels, we are likely to see an ever-increasing number of cliff falls.
Our advice as always is to come and admire our beautiful unique cliffs- but from a safe distance.