The volcanic ridges also periodically erupt hot lava to form new ocean floor, as was the case here last June.

To date, Dr. Koski said, less than 1 percent of the volcanic ridges have been studied close up.

Both plants are situated in the Hengill region; an active volcanic ridge.

The path nearest the palace takes walkers along the base of Salisbury Crags, a volcanic ridge.

It appeared just like the others: volcanic ridges and ravines, heavily overgrown with dense jungle.

They are on a chromium catwalk which follows the peak of a volcanic ridge.

The caldera has an elliptical form (14 x 9 km) and is surrounded by a steep volcanic ridge several hundred meters high.

The town lies in a small valley surrounded by steep volcanic ridges.

They occupied all the commanding places from the western edge of a volcanic ridge stretching eastwards along the high ground.

The federal government has focused exclusively since 1987 on Yucca Mountain, a volcanic ridge that lies on federal land adjacent to a nuclear test site.