28 November 2012

A damaging landslide in Whitby, England triggered by recent heavy rainfall

Posted by dr-dave

An exceptional period of rainfall, triggered by a pair of low pressures systems crossing a country with soils that were already saturated, caused considerable disruption across the UK over the weekend. The effects have been so significant that the Environment Agency has activated the Disaster Charter, which facilitates the collection and initial analysis of remotely sensed imagery after a disaster.  Activations in the UK are very rare.  In North Yorkshire, the historic fishing port of Whitby suffered a landslide that was not particularly large but has been quite damaging.  Whitby is located around the mouth of the River Esk, which has cut a steep valley into the local rocks.  The result is a large number of steep slopes upon which most of the old part of the town is built.  I have featured the landslides and rockfalls in Whitby before, although most of the the mass movements are associated with coastal erosion of one type or another.

My group has been studying coastal landslides and rockfalls at Whitby for a long time, and we have a number of long-term monitoring sites in the area.  Separately I can recommend a very nice cottage to rent in the old part of the town near the sea if you would like to pay a visit to Whitby ;-)

During the heavy rainfall a landslide occurred on the east side of the river valley, affecting the gardens of a row of Victorian (19th Century) cottages.  The Whitby Gazette has the story, with a good image of the site:

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Whilst the Guardian has a good image from the other side of the river:

Photograph: John Giles/PA

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The row of houses, called Aelfleda Terrace, has been condemned by the local council and will need to be demolished.  The problem is not that the houses are damaged – indeed the Whitby Gazette report suggests that they are unaffected by the landslide, but that there is the potential for further movement.  Collapse of the properties would put at risk the houses downslope of the terrace.

Of course this is heart-breaking for the owners of the houses (although according to the Whitby Gazette article they seem confident that the property loss will be covered by their insurance).  According to the article, local people are blaming instability in the area on apparently flawed drainage works, with suggestions of a more global issue associated with the placement of fill during construction of a car park.  It is impossible to say without a more detailed evaluation whether either of these issues is a factor.  The BBC News website indicates that the private water company Yorkshire Water have been in discussions with the house owners prior to this event.

For info the image below shows the Google Earth imagery for this area, collected in 2009.    The resolution of the imagery is not good enough to see whether the slope in question was showing signs of distress at this time:

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According to Rightmove, one of these properties sold in 2007 for about £200,000, suggesting that about £1 million worth of property has been destroyed.