Nuees Ardentes

One of the more frightening of volcanic eruption phenomena is the nuee ardente, or glowing cloud. It happens quickly and is hard to escape from; one of the reasons why it is wise to evacuate people from volcanoes that erupt explosively.

Nuees ardentes are billowing masses composed of incandescent dust and ash buoyed up by hot gases. A nuee starts with an explosive volcanic eruption that spews the hot material upward or obliquely outward from a vent. After expanding upward hundreds or thousands of feet, the boiling, angry-looking cloud spreads out and falls downslope with ever-increasing speed and, "at the same time," one viewer said, "developing upward in cauliflower convolutions of dust and ash. These convolutions grow with an indescribably curious rolling and puffing movement which at the immediate front takes the form of forward-springing jets, suggesting charging lions."

With searing temperatures that may exceed 500°F the nuee races downhill at speeds in excess of a hundred miles per hour, typically killing all animal life in its path.

The most famous of all nuees is one that swept several miles down the slopes of Mt. Pelee in 1902 to kill all except two of 30,000 persons in the town of St. Pierre, Martinique. One survivor was in a house on the fringe of the hot cloud, though several others in the same room were killed. The other known survivor was a convicted criminal locked into a subterranean cell. Even there he suffered severe burns and shock. Later he was pardoned and became a celebrity because he had survived. This proves, it has been said, that crime pays.