Heat reveals history’s markings
The UK has experienced the longest heatwave in five years. The hot weather started on 24 June and lasted until 9 July, which meant for 16 days in a row temperatures reached above 28°C. The highest temperature in the UK so far this year was recorded in Porthmadog in north Wales, where it reached 32.6°C.
The unusually long period of sunshine has had some surprising benefits. Although many people have been enjoying barbecues and going to the beach or park, Dr Toby Driver has been flying above Wales looking for long-lost historical sites that are now visible thanks to the hot, dry weather.
Driver works as an aerial investigator for the Royal Commission on the Ancient and Historical Monuments of Wales and has been mapping cropmarks. These are patterns on the ground that reveal the presence of buried archaeological remains, which show up when the land becomes very dry. For example, the remains of a stone wall could lie just below the surface. If rain is scarce, crops on top of the remains won’t grow because their roots can’t reach deep enough to find water, and the shape will show up yellow. A filled-in ditch dug long ago for defence will still hold more moisture than the ground around it, revealing its form in lush green. Driver has identified several new Iron Age (800BC – AD43) and Roman (AD43 – 410) settlements and monuments.
However, the hot weather has not been good news for everyone. In Ireland, a hosepipe ban has been introduced because water levels are running low. This ban means people can’t use a hose to water their plants, wash their cars or fill up ponds or paddling pools. In Scotland, a water company has asked customers not to have baths, to keep showers short and to turn off the tap while brushing their teeth to help save water until it rains again. A hosepipe ban is also in place in Northern Ireland. English and Welsh authorities are thinking about whether to introduce a similar ban, and are moving water from north Wales to north-west England to help with a water shortage in the region.