Some volcanoes explode with the force of an atomic bomb. Others spill rivers of gently flowing lava.
What causes volcanoes to erupt? How do scientists study them? Let’s explore one of the most powerful, destructive volcanic eruptions in history.
More than a century ago, the city of Saint-Pierre was known as the Paris of the Caribbean. Located on the island of Martinique, Saint-Pierre was a center of trade in rum, sugar, cocoa, and coffee. Its boulevards were lined with beautiful homes and shops.
But in the spring of 1902, all of that changed…
On the morning of May 8, the nearby volcano Mt. Pelée exploded in a burst. A swirling cloud of hot gas, ash, and rocks, called a pyroclastic flow, rushed down the mountainside at 480 kilometers per hour (300 mph). It burned everything in its path, including the town of Saint-Pierre and nearly all the ships in the harbor. Within two minutes, close to 30,000 people were dead.
“No one ever thought of fearing the volcano, which all thought to be extinct… the people wandered about by thousands, never dreaming that there was any danger.”
News of the disaster horrified the world. Geologists were drawn to Martinique to understand the science behind the tragedy. The American Museum of Natural History sent geologist Edmund Hovey.
Take a look at what Edmund Hovey saw and collected.
Nearly every Carribean island has its own active volcano. That’s because these islands lie above subduction zones, where one tectontic plate sinks, or subducts, beneath another.
Find out how subduction causes volcanoes to form.
“Mt. Pelée was incredibly explosive. It’s like twisting off the top of a soda bottle!”
It’s all a matter of chemistry. The way a volcano erupts depends on the amount of gas and silica (a molecule of silicon oxygen) in the magma below. Magma with lots of silica is thick and gooey, while magma low in silica is thin and runny. And in magma with lots of gas, bubbles form as it rises. The more bubbles that form, the more explosive the eruption!
Mt. Pelée was the most explosive type of volcano: it was high in silica and high in gas. This type of volcano is called a stratovolcano.
Explore how different shapes of volcanoes have different kinds of eruptions.