A massive landslide has occurred along the eroding Jurassic Coast in Britain, just weeks after a significant 300-foot-long crack developed at the cliff’s summit.

Thousands of tons of rock and earth have cascaded onto the beach at Charmouth, Dorset, swallowing a portion of the well-trodden South West Coastal Path.

A 30-foot-wide segment of the towering 450-foot cliff has detached from the mainland, now resting roughly 20 feet below its previous position.

Enormous mounds of mud have tumbled onto the beach, rendering it inaccessible for visitors.

This incident adds to a series of substantial rockfalls along these rapidly eroding cliffs in recent weeks.

Specialists attribute the dramatic shifts in the 175-million-year-old cliffs to weeks of persistent rainfall.

Coastguards are urging members of the public, especially fossil hunters, to keep away from the base of the cliffs as another landslip could happen at any time.

They have closed the stretch of coastal path at Stonebarrow and the beach below to prevent future tragedies.

An aerial view of an ongoing landslip on Stonebarrow Hill at Charmouth in Dorset which has closed the South West Coast Path

 The 30ft wide section of the 450ft tall cliff has split away from the mainland and is now about 20ft lower than it

Experts believe the dramatic movement in the 175-million-year-old cliffs is the result of weeks of relentless rain

Fossil hunter Chris Moore said: ‘It’s very impressive. If you go down to the beach in Charmouth there’s now a pile of mud and trees which stretch out to sea.

‘I looked from the top and about 30ft of coastal path has gone, as the front of the cliff has dropped by anything between 5ft and 50ft down the cliff face.

‘It is a bit like one of those arcade games, push penny things, where the top slips and it pushes every layer below which eventually ends up on the beach, replenishing it with fossils.

‘The next bout of rain we get, they are going to slip further down the cliff, so people should never stand on the cliff edge and also should look out for any lines or tears in the grass which means that a section is about to go.’

Dorset Council had been monitoring the area for movement for some time after a large crevice appeared on the land at the top of the cliff several years ago.

A council spokesperson said: ‘There’s been a large cliff fall and mudflow at Stonebarrow, Charmouth.

‘The coastal path is currently closed and we are working on a diversion.

‘Rockfalls and landslips can happen at any time.

‘The Jurassic Coast is a UNESCO World Heritage Site recognised for its outstanding rocks, fossils, and landforms.

‘It is a 95-mile long stretch of coastline within the counties of Dorset and Devon.

‘It looks the way it does because of erosion from weather and the sea. Rockfalls and landslips are part of the movement which makes up the unique nature of this coastline.’

Coastguards are urging members of the public, especially fossil hunters, to keep away from the base of the cliffs as another landslip could happen at any time

The stretch of coastal path at Stonebarrow and the beach below has been closed off to prevent future tragedie

 Dorset Council had been monitoring the area for movement for some time after a large crevice appeared on the land at the top of the cliff several years ago

Earlier this year, a sizeable section of the 150ft cliff at West Bay in Dorset collapsed without warning while members of the public walked close by.

Witnesses reported hearing loud cracks in the cliff face seconds before it gave way, giving them enough time to run for safety.

Around 500 tonnes of rock and boulders the size of small cars fell onto the popular beach, sending a huge dust cloud into the air.

When it cleared it revealed a 30ft pile of sandstone rock that cut off the beach.

And coastguards are monitoring an ‘active and ongoing’ landslip taking place on the 150ft cliffs above Monmouth Beach in Lyme Regis.

A spokesperson for Lyme Regis coastguard said: ‘We strongly advise all members of the public to stay well clear of this area. Do not attempt to climb the slip or walk near the base of the affected cliffs.

‘The cliffs along the Jurassic Coast are naturally unstable and can crumble without warning.’

In 2012 holidaymaker Charlotte Blackman, 22, was crushed to death by a rockfall as she walked under the cliffs further along the beach at Burton Bradstock.