Rest and Be Thankful (A83) landslide, 2013

Rest And Be Thankful location

Following a period of heavy rain, on 3 October 2013 a debris-flow landslide occurred along the A83 Rest and Be Thankful pass (Argyll and Bute, Scotland). It was reported that 27 mm of rain fell in a few hours on the morning when the landslide occurred.

It was also reported that 100 tonnes of material blocked the road that was subsequently closed in both directions resulting in a long diversion.

The BGS Landslide Response Team made a visit to the landslide on 4 October 2013 to record the failure. Information collected for the BGS National Landslide Database (ID 18954/1).

Rest and Be Thankful A83 landslide. October 2013. Photograph courtesy of Strathclyde Police/PA.

Road closures

October 2013 Rest and Be Thankful A83 debris flow landslide.  Taken from the road looking upslope.  The landslide debris has been removed from the carriageway.

This is the seventh time the road has been closed in the last five years:

Landslides are frequent occurrences along this busy transport route causing considerable disruption and expense when the road is closed.

To ease this situation, an Emergency Diversion Route has been completed partially utilising the route of the Old Military Road. Additionally, a route study report and associated consultation feedback paper were published on 22 February 2013:

Geology

The area in which these failures have occurred is steeply sloping ground underlain by rocks of the Beinn Bheula Schist Formation. These are composed of psammite and semi-pelite rocks that are metamorphic in origin. These are composed largely of quartz, feldspar and mica minerals. These rocks are commonly intensely foliated and spectacularly folded; extensive quartz lenses and veins also occur.

The bedrock plays little part in the landslide activity on these slopes. The recent landslides here have largely been associated with slope deposits, including peat and topsoil as well as the underlying layers of colluvium. The colluvium comprises sandy to gravelly silts and clays, with varying amounts of cobbles and boulders. The colluvium deposits on this slope represent earlier phases of slope instability.

Additional photos

Remains of the landslide that blocked the A83, October 2013. Debris has been removed from the carriageway.
Rest and Be Thankful Oct 2013 debris flow landslide above the road.  Debris has been cleared from the carriageway.

Contact the Landslide Response Team

British Geological Survey
Keyworth
Nottingham
NG12 5GG
E-mail: Landslides team
Telephone: 0115 936 3143
Fax: 0115 936 3276