Huge 100-tonne rock chunk crashes off 150 million-year-old cliff after stormy weather

A huge chunk of rock weighing around 100 tonnes has broken off from a 150 million-year-old cliff, smashing into the waves below.

Incredible pictures from Portland Bill on Dorset’s Jurassic Coast show the exposed cliffside after the dramatic event.

The break comes after recent stormy weather, with locals commenting they could see the rock beginning to crack under the pressure from the incoming winds.

Strong waves whipped up by south westerly winds have crashed against the base of the cliff, ultimately causing the massive block of rock to break off.

Portland resident Jeffrey Webb noticed the dramatic fall walking his dog on Wednesday night.

He returned with his camera on Thursday to capture it the aftermath.

The fall happened about 25ft from Red Crane, a fisherman’s crane erected on a disused stone loading quay which is an ancient monument, and the whole area is popular with walkers and visitors.

Marcus Dampier-Smith, who owns an old coastguard cottage on Portland Bill, said: “This chunk of rock has been marked for falling for a while now.

“We’ve seen the large cracks running through it and knew it was only a matter of time.

“We’re lucky here that we have relatively little erosion in comparison to further along the Jurassic coast. But when chunks go here, they tend to go big.

“People love Portland Bill and walking over the rocks, but should pay attention to cracks and keep back from the edges. People do take risks.”

A similar rock fall happened further along the Portland coast just over a year ago and in 2014 Pom Pom rock, an ancient rock stack on Portland that weighed hundreds of tonnes, was destroyed by high seas in a storm.

The whitbed limestone is a hard rock but has natural fissures which the weather erodes.

Dane Gould, from Portland Bill Coastguard team said: “The rock falls we get are not as big as some further along the coast, but they look very dramatic because the rock falls away in big chunks.

“This one is about 100 tonnes. The stone has natural fissures through it and the weather and waves have got in between the cracks and undermined it, gradually working it loose and then a big wave has got the pressure around the stone and pulled it away.

“A big wave can have a lot of power, people underestimate it. It could be dangerous if you walk on the wrong part, because it could fall away at any time.”