Wildfires on permafrost are ravaging Yakutia - or the Sakha Republic - the largest and coldest entity of the Russian Federation. The scale is mesmerizing. There are some 300 separate fires, now covering 12,140 square kilometers - but only around half of these are being tackled, because they pose a threat to people. The rest are burning unchecked.

Russia's Aerial Forest Protection Service is trying to suppress 136 fires over 43,000 hectares. Firefighters are using explosives to contain the fires and seeding clouds with silver iodide to encourage rain.

This tadpole-shaped gash in the Earth's surface - around one kilometre long, and 800 metres wide - is enlarging by up to 30 metres a year.