The Yamal Craters
In 2014, helicopter pilots in Arctic Siberia spotted a giant hole in the tundra that hadn't been there before.
What was reported
In July 2014, helicopter pilots flying over the Yamal Peninsula in Arctic Siberia spotted a huge, deep, round crater in the tundra, about 30 metres wide, with soil scattered around its rim as if blasted out. It made news worldwide, with theories ranging from a meteorite to a missile.
Since then, around 20 similar craters have been found in the region.
Explanations offered
Scientists have concluded that the craters form when methane gas builds up under mounds of frozen ground as the permafrost thaws, until the pressure becomes too great and the ground bursts. Warmer summers in the Arctic are thought to be making them more common.
- When
- First found in 2014
- Where
- Yamal Peninsula, Russia
- Witnesses
- Helicopter pilots and scientists
- Status
- Mostly explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.