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Once volcanoes start to erupt, nobody can stop them.
But by studying them, we can lessen the damage. Information about a volcano’s past tells scientists how it may act in the future. Volcanologists study volcanoes. They look at old lava flows, ash layers, and other clues. They make a history of eruptions over millions of years.
Volcanologists also study the daily life of volcanoes. That helps them find the warning signs of new eruptions. Some signs are easy to see. Those include more ash or fumes coming from the crater. Other signs, like little earthquakes, are so small that only special instruments can notice them. These methods are not perfect, but they are getting better. And it beats just guessing!
▲ A volcano observer climbs Indonesia’s Mount Merapi for five hours. Then the scientist tests the volcano with a temperature probe. It measures the heat of escaping gases. Indonesia has 130 active volcanoes. A staff of observers keeps track of them.
◀ Geologists use a theodolite (thee-ODD-uh-lite). That’s a telescope that lets scientists measure a landscape. They look for changes in a volcano’s crater. Keeping track of the changes can help them predict an eruption.
▲ Dante the robot looks like a spider, with eight legs and six eyes. It was built to crawl into a volcano called Mount Erebus. That’s in Antarctica. Dante’s job is to study lava and gases.
◀ Scientists predicted a 1975 eruption in Russia. They tracked small earthquakes to figure out when the Tolbachik volcano would erupt. They got it right, too. So right, TV cameras were there when it happened!
▲ A scientist in a fire-resistant suit takes lava samples. Experts track changes in the lava. It helps them learn more about how a volcano works.
▲ Studying active volcanoes can be dangerous. Volcanologist David A. Johnston was killed in the 1980 eruption of Mount St. Helens. He had been watching the volcano. An eruption was likely, but no one knew when it would come or how big it would be.
◀ A Hawaiian woman makes an offering to Pele. Pele is the goddess of volcanoes. Island folklore says that when she’s angry, she sends waves of lava from the underworld. We now explain volcanoes with science. But Pele is still important in Hawaiian folk tradition.
▲ In Japan, some places are in the path of active volcanoes. People living there practice evacuation drills all the time. They know predictions won’t help if they’re not ready for disaster.
◀ Thomas A. Jaggar had the idea to put permanent laboratories on the sides of volcanoes. He founded an observatory on Hawaii in 1912. Now there are dozens more around the world.
Check It Out!
Every year, about 50 volcanoes erupt on land or in shallow water. But how many could actually erupt?
There is no exact answer. That’s because each volcano has its own special history. For some volcanoes, the time between eruptions might be days. For others, it could be hundreds or even thousands of years.
