0:00 / 4:29
How Can Fires Burn Underground?
A TED-Ed lesson on 'zombie fires' — flameless blazes that smolder underground in peat for months. Learn the three things a fire needs, how smoldering differs from flames, and why peatlands are so flammable.
How it works
- Press play to start the video.
- Videos 5 minutes or longer pause once or twice for a quick check. Get it right and you're on your way. If not, you'll see a friendly explanation and the video simply keeps going. Short videos skip the checks.
- At the end there's a 4-question test. Score 60% or more to complete the lesson, and 80% or more to master it. You can always watch again and try for a higher score.