It's the result of volcanic activity only three hundred million years ago.

In fact, the mid-ocean ridges form the largest volcanic systems on Earth.

The island was small, a single volcanic cone rising from the sea.

Obsidian is rare, of course, because of the lack of volcanic activity.

GNS video explainer on the volcanic alert level system in New Zealand

The tension went out of his attitude; the volcanic fires died down.

Police say eight people are still missing after Monday afternoon's volcanic eruption.

This goes with the recent volcanic hazards map prepared for the volcano.

And up ahead he saw the rising steam of the volcanic fields.

They knew that the central region of the Ika-na-Mani is essentially volcanic.

His splendid confidence, his volcanic enthusiasm carried me out of myself again.

The whole summit was enveloped in clouds of vapour and volcanic dust.

The whole mountain was enveloped in clouds of volcanic ashes and vapors.

Major natural disasters such as earthquakes, tsunamis, volcanic eruptions, and geomagnetic storms.

You had to be young, he supposed, to enjoy a volcanic eruption.

It seemed chiseled in the dark-red, volcanic lava of his Sooner wilderness.