A Journey Into A Mysterious Siberian Crater

Scientists prepare to descend into the largest of the three craters on the Yamal peninsula.

A scientist rappels down the side of the crater to reach a frozen lake at the bottom. The expedition took place in winter because the freezing temperatures had stabilized the structure.

Researchers took measurements and samples from the crater. Initial research suggests that the crater was formed by melting gas hydrates, icelike substances below the surface of the Earth.

Scientists stand on the frozen lake at the bottom of the crater.

The team collected samples of ice and rock.

The view from the bottom

A researcher rappels down a frozen wall.