The Holbeck landslide, south of Scarborough in North Yorkshire, attracted considerable interest when it destroyed the four-star Holbeck Hall Hotel between the night of 3 June and 5 June 1993. A rotational landslide involving about 1 million tonnes of glacial till cut back the 60 m high cliff by 70 m. It flowed across the beach to form a semicircular promontory 200 m wide projecting 135 m outward from the foot of the cliff.
The likely cause of the landslide was a combination of: rainfall of 140 mm in the two months before the slide took place; issues related to the drainage of the slope; pore water pressure build up in the slope and the geology.
The first signs of movement on the cliff were seen six weeks before the main failure, when cracks developed in the tarmac surface of footpaths running across the cliffs. These were filled to stop ingress of water to the cliff, but when the cracks reopened, shortly before the main failure, the council closed the cliff paths below the hotel. At this time a small part of the hotel garden was also observed to have suffered a minor movement.
There was originally 70 m of garden between the hotel and the cliff edge. At 6 am on the 4 June a guest saw that 55 m of the garden had disappeared. The hotel was evacuated and the landslide continued to develop, culminating in the collapse of the east wing of the hotel by the evening of 5 June.
The landslide is a rotational landslide degrading to a mud/debris flow which covered the rocks on the beach (platform).
The cliff consists of Glacial Till (sandy, silty clay) resting on a low cliff of the Middle Jurassic Scalby Formation. The Scalby Formation comprises Scalby Mudstone and Moor Grit (sandstone).
The landslide is National Landslide Database ID 10741/1. Here are a selection of photographs of the landslide:
Forster, A. 1993. Scarborough Landslip. Geoscientist Vol. 3. No.5. pp 2-3 and cover photograph.
Forster, A, and Culshaw, M. 2004. Feature: Implications of climate change for hazardous ground conditions in the UK, Geology Today, v.20 issue 2, pp. 61–66
Lee, E M. 1999. Coastal planning and management: the impact of the 1993 Holbeck Hall landslide, Scarborough : East Midlands Geographer Vol 21 pt 2 1998 & v.22 pt1, p78–91
Contact the Landslide Response Team
British Geological Survey
Telephone: 0115 936 3143
Fax: 0115 936 3276
The section covers
- Hard Engineering
- Soft Engineering
Managing coasts can be tricky. Techniques can be divided into hard engineering and soft engineering.
Advantages and disadvantages of hard engineering schemes
- Sea Wall: Placed at the base of a cliff to reflect the waves energy. They are very expensive at approximately £10,000 per km, but extremely effective at protecting areas from flooding. Environmentally ugly.
- Gabions: Cages of wire filled with rocks to absorb the waves energy, they are effective and cheap but environmentally ugly.
- Groynes: Can be made of wood or rock and are long vertical structures placed at right angles to the beach to trap sediment. This builds up the beach and protects the cliffs from erosion. They are effective at building up the beach therefore protecting cliffs from wave attack. Can result in areas further down the coast being starved of beach material resulting in more erosion! Only last 25-30 years.
- Rip Rap (Rock armour): Large rocks placed at the bottom of the cliff to absorb the wave energy, they are effective at dipersing the waves energy and cheap. Environmentally ugly and may put off tourists.
Examples of hard engineering
Soft Engineering is a less environmentally noticeable way of managing the coastline.
- Beach Nourishment: Large amounts of sand are added to beaches to build them up and help absorb wave energy. This protects tourism as well as the coast and is easy to carry out and fairly cheap. But it does not last very long as sand will continue to be transported along the coast by longshore drift.
- Managed Retreat: This allows the natural erosional processses of the sea to occur, areas of low value land are allowed to flood hopefully protecting more important areas further down the coast.
- Cliff Stabilisation: Cliffs are covered in matting and vegetation planted to help make them more stable and resistant to erosion.
- Do nothing: Obviously the cheapest and most environmentally friendly option! However, you have to weigh up the COSTS (to people, tourism and buildings) against the BENEFITS (advantages of letting the area return to its natural processes). If the costs greatly outweigh the benefits e.g. by having to rehome many people or losing valuable tourist facilities then other options will have to be looked at.
The Holderness Coastline in East Yorkshire is the fastest eroding coastline in the world
Case Study: Holderness
The Holderness coast is threatened by fast rates of erosion and in addition the beach areas, which are important for tourism around Mappleton, are being depleted at an alarming rate. (In some areas it is as fast as 5m per year)
Why? The cliffs are made of soft boulder clay therefore they are quickly eroded by the power of the sea and sun aerial processes (physical and biological weathering).
- 29 villages have been claimed by the sea in 1000 years
- Farmers are losing valuable farmland Holiday caravans have collapsed into the sea
- In June 1993 the Holbeck Hall Hotel slumped into the sea
- Sea defences at Mappleton are causing problems further along the coast as there is less sediment to travel down
- £2 million was spent on putting in a ‘rip rap’ large granite blocks to absorb the waves energy at Mappleton
- 2 rock groynes were erected to build up the beach at Mappletopn
- A sea wall has been erected at Eastington to protect the gas station
- Offshore reefs of old tyres along the coastline
A dairy farm is threatened by coastal erosion at Holderness, East Yorkshire
This video shows a dairy farm on the Holderness coastline in Yorkshire is being lost to the sea through coastal erosion. The farmer is interviewed and explains how much land and how many farm buildings have been lost and what the impact of this has been. Aerial photography is used to show how much land has been washed away during an 8 year period.