Blazes during the past decade have caused some of the worst bushfire devastation seen in Australia, with hundreds of thousands of hectares destroyed, some 180 people killed and thousands of homes and buildings lost. Extreme fire conditions increased the severity and intensity of fires and prompted the creation of a new fire alert level – catastrophic

There are many ways a bushfire can start, but for a fire to keep burning it needs fuel, oxygen and heat. Hot, dry and windy conditions and a large amount of dry vegetation can turn a small spark into a destructive blaze that can take weeks to bring under control

The interactives below show the course of four recent, terrible bushfires. They track conditions over time, including the number of fire hotspots*, wind speed and direction, temperature and the usual average temperature. The coloured dots show the most recent fires at the fire front (yellow), movement of that fire in the past 24 hours (red) and its path of destruction over the previous week (grey)

*These are hotspots detected from satellite are gathered by NASA, and in some cases include sources of heat other than bushfires. A single fire will often result in many hotspots