UK: A new surveying technique developed at the University of Nottingham is giving geologists their first detailed picture of how ground movement associated with historical mining is changing the face of our landscape.
The new development by engineers at the University has revealed a more complete map of subsidence and uplift caused by the settlement of old mines in the East Midlands and other areas of the country and has shown that small movements in the landscape are bound by natural fault lines and mining blocks.
It appears to support concerns that movement associated with historical mining is continuing far longer than previously anticipated.
The research has been led by Dr Andrew Sowter in the University’s Department of Civil Engineering. He said, “This method allows us to measure patterns of slow millimetre-scale movement across large regions of the landscape and, in the UK, almost everywhere we look is dominated by our industrial past. Large tracts of our land, including parts of our cities, towns and infrastructure as well as agricultural and woodland areas, are steadily creeping upwards over mines that were closed decades ago.”
The new development builds on existing technology that allows engineers to use satellite radar technology to measure points on the landscape over a length of time to assess whether they are moving up (uplifting) or sinking down (subsiding).
Previously, this has relied on using fixed, unchanging objects like buildings that can be accurately re-measured and compared against previous measurements time after time. However, the technique has not been practical for use in the rural landscape meaning that geologists could only get half the picture.
Now, Dr Sowter has developed a technique called the Intermittent Small Baseline Subset (ISBAS) method which adapts the same technology and extends it to rural areas by taking stacks of these radar images and identifying those more transient points in the rural landscape against which changes over time are able to be measured.
The technique is now being used by the British Geological Survey (BGS) , based in Keyworth in Nottinghamshire, which is the world’s oldest national geological survey providing expert services and impartial advice on all areas of geosciences for both the public and private sectors.