1. NORTH NORFOLK COASTAL EROSION
Charles Lydon & Jonathan Staley

2. GEOLOGICAL BACKROUND
Glacial depositions along region during the Pleistocene period
Loose heterogeneous sedimentary rock south of Sheringham
Chalk outcrop at Overstrand shown in wave-cut platform

3. GEOLOGICAL FEATURES These are examples of the cliffs at Happisburg
Above shows the soft sedimentary rocks of Glacial Origin
On the right shows the wave cut platform made of clay
Coast retreating at 5m per year

4. PHYSICAL PROCESSES
Wave erosion undercutting small cliffs e.g Happisburgh (<10m)
Water Quickly erodes weak material and transports it away
Steep cliff face maintained
Translational Failure in areas of larger cliffs (20m)
Groundwater percolates through loose gravels and ponds on top of impermeable clay
P.W.P increases
Shear strength decreases

5. HUMAN USE
Large population living in coastal towns of Cromer and Sheringham
Beaches Provide tourist industry in area, feeding the local economy
Lots of static caravan sites in cliff top locations
Bacton Natural Gas Terminal supplies lots of the country’s natural gas, therefore industrial importance
Cliff erosion not only a threat to the local communities of North Norfolk but also to the national economy
Therefore must be managed and controlled

6. ALTERNATIVE APPROACHES
Beach Nourishment
Managed Retreat
Sea Walls
Groynes
Breakwaters – permeable or detached
Maintaining spits
Soft Engineering

7. SHERINGHAM – Hard Engineering
Important business/shopping/ tourism centre
Sea wall constructed in 1994 costing £6.4mil
Earlier defences reached end of life
Metamorphic rock imported from Norway

8. HOLME – Soft Engineering
Sea levels increasing and area is low lying (all >50m a.s.l)
Main defence is fragile sand-dune ecosystem
Back of the dunes were planted with Corsican pines & Marram grasses
Beach Nourishment attempted in 90’s but proved to be ineffective
Experimental protection work showing gabions, chestnut fencing and conifers

9. HAPPISBURGH Managed Retreat
Under current N.N.D.C. Shoreline Management Plan , Happisburgh is designated as a coastline where a policy of MANAGED RETREAT is in operation.
 Erosion seemingly accelerates and properties disappear  
The original 1950's sea defences with wooden revetments ,wooden groynes and steel piling have not been maintained
Hydraulic action by waves behind the steel piling has undermined the sea wall