The UK (and many other areas of the world) has been experiencing a prolonged heatwave this summer. Some love it, and some hate it, but it’s clearly been fantastic for archaeologists. In the dry weather, grass and crops dry out at different rates depending on what the soil underneath is like – where there was a wall at some time in the past, the grass dies more quickly, leaving parch marks. These parch marks have led to the discovery and re-discovery of past structures across the country.
Here’s a diagram from the Royal Commission on the Ancient and Historical Monuments of Wales on how this works:
This BBC article also explains how the parchmarks work, with a series of amazing pictures – the most significant find is the discovery of a new henge structure at Newgrange in Ireland.
This is not my area of specialism at all, but I’ve been fascinated by all the images that people have posted on twitter in the past couple of weeks. They’re still coming thick and fast, so you might want to check the #parchmarks hashtag to keep up with developments. In the mean time, here’s a round-up of some of my favourite heatwave archaeology images from the UK.
I think this first one might be my favourite – a Roman fort appears!
If you’re not excited by a Roman fort, how about an entire mansion?
The weird irregular shape of a fort on the contemporary map is 100% confirmed by the parch marks:
A smaller scale example, as the pattern of paving of a Roman road appears:
A First World War POW camp in the Scottish Borders:
Ghostly buildings appear outside King’s College, Cambridge (check the thread for more info about what these buildings were):
A Roman road appears near Silchester:
WWII air raid shelters on Jesus Green, Cambridge:
Featured image: Mark Walters, Skywest Surveys. Creative Commons License NC-ND 4.0. @MarkWalters_