The cliff collapse at Barton-on-sea

The reasoning of the cliff collapse at Barton-on-sea, was due to many different causes in this blog there will be the developed causes and what effect this could have had on any residents in the area, the local tourism, the wildlife and also the physical landscape. There will also be some information on what the previous coastal defences were and the ones that are employed currently and have been since the 1970's when the largest cliff collapse occurred.


What happened at Barton-on-sea?


This picture was taken in 2008 on May 29th after the collapse had occurred, though it is thought that the land slide had started from the 15th as that is when the first cracks in the cliffs started appearing.

However this area was lucky in the aspect of cliff collapse as previously in 2004 it had all been grass area and so no buildings in this part were affected too much. The other areas were on the other hand
were not as fortunate as they had buildings and properties there.

The types of cliff collapse that occurred at Barton-on-sea were that of sliding and a rotational slumping. 

Many extensive defences had been placed at the coast prior to the landslip in 2008, due to this landslide there was a renewed concern about the vunerability of the cliffs in this part of the coast. An older development of housing in Barton Court is now just 20 metres from the edge of the cliff tops. It has been predicted by the local authorities that these houses will be lost due to coastal erosion during the next 10-20 years.

What defences were put into place at Barton-on-sea?

Some coastal protection measures at Barton were installed in the late 1930s but fell into disrepair during World War II. In 1964 a series of timber groynes and a cliff drainage system was installed along 300m of the sea-front. This was followed in 1965-8 by a timber revetment backed by large rocks; an extension to the drainage system; and some rock groynes.  Later improvements have consisted of replacing the timber groynes with rock groynes; and replacing the timber revetment with a rock structure of dark grey limestone boulders to protect the toe of the cliff. Today’s cliff slip problems are largely due to inland water seepage. There have been recent experiments with vegetation defences (planting shrubs, plants and trees on the cliff face) to prevent rotational cliff slump, and therefore slowing the retreat of the cliff towards land which is in use.

What causes were there for the landslip?

-The rocks that the cliffs consist of are made up of gravels, sands and clays. This means that they are easily eroded and have little strength to resist collapse.(gravels and sands are permeable and they will absorb any water content that enters it. Clay is however impermeable and though this is the case, it becomes extremely slippery when it comes into contact with water, this causes land mass movements such as slides and slumping)
-The arrangement of the rocks will cause the water to pool up within the cliffs and then the water pressure within the cliffs will encourage cliff collapse.
-The area of the coast has a south-westerly pevailing wind, this means that long shore drift will occurr and pass the sand towards the hurst castle spit.
-In the same continuum, a large groyne or barrier has been built at Bournemouth, this means that any long shore drift that should bring a replenishment of sand, is being caught up at Bournemouth beach. This causes the destructive waves to have more effect on the cliff faces because there is less friction on the beach to slow the waves down.

-There are several small streams (bunnys) that run towards that area of the coast, however they dissapear into the permeable sands before they can reach the sea, this causes a larger build up of water in the cliffs.
-The large number of buildings that are situated on top of the cliffs will add weight to them, this will make them more vunerable to collapse, it can also interfere with any natural drainage systems inside the cliffs.     Becton Bunny

Effects that this had on people and the area

-The properties of people would have been endangered, destroyed or in the very least circumstances, damaged some beyond repair.
-There will be a reduced tourism industry as the beaches will not have as pleasant aesthetics in comparison to other beaches and the beaches that Barton-on-sea had prior to the cliff collapsing.
-It could have made the cliffs weaker to future coastal erosion that may occurr.
-The resident's housing may have been destroyed and they may have had to move or relocate because of this.
-Any industry in the area may have been damaged which could also mean that employment could decrease as if there are less buissinesses, less people will need to be employed by them.