Going up in the world, Devon village that’s rising by 2cm a year – and nobody can figure out why
WITH its thatched cottages and cosy pub it’s no surprise that Willand is an up-and-coming place to live.
The trouble is it’s not just house price that are on the rise. Many of its buildings are too... by about 2cm a year, to be more precise.
The uplift is puzzling geologists who have used satellite images to see that a domeshape is forming across about a square mile of the community.
Experts have unflatteringly described Willand as a ‘pimple on the face of Devon’ and believe the answer to the ‘weird’ phenomenon can only lie deep underground.
The change was detected from more than 2,000 radar images acquired by the European Union’s Sentinel-1 satellites.
From these images, experts created a map to reveal hazardous areas of subsidence and uplift, such as those created above former mine tunnels.
Dr Andy Sowter, 56, of Geomatic Ventures Ltd, which carried out the survey, said: ‘We did a two-year survey and over that period, from October 2015 to October 2017, it rose on average 2cm per year maximum. It’s like we can see a dome, in the middle it is rising 2cm per year and 0.2cm at one side.
‘The rate at which it is rising is increasing towards the centre and decreasing on the other side. The villages around Willand are not rising at the same level.
‘But it is important because it straddles the M5 and a major railway line. We see similar rises in coal mining areas, we have done extensive surveys over the Midlands and up to Northumberland. ‘Mines fill with water if you don’t pump them and when they are pumped they dry out like a sponge. If you fill them with water again they swell, that results in uplift.
‘That’s what we have seen in Willand, which is not a mining area. That is why this is a little odd, it is consistent with the rise caused by underground water.
‘We don’t exactly know what’s happening here. The level of rise is very small still so it’s not likely to be noticeable to the general public and unlikely to affect buildings.
‘But what is interesting is if this is a symptom of underground water rising then it is affecting water underground, and that is more important, because as it rises to the surface it could affect agriculture.’
Dr Sowter has contacted the Environment Agency and they are investigating.
A relative deformation map of the United Kingdom has been created from 2,000 images and it shows an average vertical height change in millimetres per year.
The map has also revealed a subsidence bowl more than 500 metres across at Kennington Park, quite close to the The Oval in London. The Team believes it was due to the sinking of a shaft for the Northern Line extension last November.
The peatlands of Caithness and Sutherland in the north of Scotland are subsiding in what is called Flow Country.
As they subside they release greenhouse gases into the atmosphere.