This is an image of a pyroclastic flow going down the slopes of a volcano to the sea.
Click on image for full size
Image from: U.S. Geological Survey, photo by B. Yount
Mt. Pelee is not a very tall volcano, in fact it is an example of what is called a "lava dome".
An extremely destructive
eruption of Mount Pelee occurred in 1902. A coastal town, about 4 miles downslope to the south,
was demolished and nearly 30,000 inhabitants were killed almost instantly.
During the eruption, a burning cloud of hot ash and gases swept into the town at a speed of 100 miles per hour. This picture illustrates the same kind of flow coming down an Alaskan volcano.
Survivors of this eruption included one man who was in an underground jail cell, as well as sailors who were off-shore and witnessed the destruction of the city from a distance. Comments by these eyewitnesses included the following:
- "The mountain was blown to pieces, there was no warning."
- "It was like a giant oil refinery."
- "There was hurled straight toward us a solid wall of flame. It sounded like a thousand cannon."
- "The wave of fire was on us and over us like a flash of lightning. It was like a hurricane of fire."
- "The town vanished before our eyes."
Shop Windows to the Universe Science Store!
You might also be interested in:
Ash is made of millions of tiny fragments of rock and glass formed during a volcanic eruption. Volcanic ash particles are less than 2 mm in size and can be much smaller. Volcanic ash forms in several ways...more
Cinder cones are simple volcanoes which have a bowl-shaped crater at the summit and only grow to about a thousand feet, the size of a hill. They usually are created of eruptions from a single opening,...more
Lava can move in broad flat lava flows, or it can move through tight channels or tubes. Lava flows tend to cool quickly and flow slowly. The fastest lava outside of channels moves at about 6 mi/hr an easy...more
Plates at our planet’s surface move because of the intense heat in the Earth’s core that causes molten rock in the mantle layer to move. It moves in a pattern called a convection cell that forms when...more
Many kinds of surface features are clues that our lithosphere is sliding. Two types of features can form when plates move apart. At mid ocean ridges, the bottom of the sea splits apart and new crust is...more
Magma consists of remelted material from Earth's crust and fresh material from other regions near the Earth's surface. When magma is erupted onto the surface in the form of lava, it becomes silicate rock....more
As the Earth cools, hot material from the deep interior rises to the surface. Hot material is depicted in red in this drawing, under an ocean shown in blue green. The hotter material elevates the nearby...more