Orting, Washington, is a lovely little town, tucked snugly under majestic Mount Rainier. But the town's towering neighbor holds a nasty secret. Beneath the 14,410-foot mountain's sugary caps, perhaps 100 miles down, lies a giant, smoldering pot of magma--liquid rock at 2,000°F. The magma is slowly cooking the rocky insides of Mount Rainier into unstable clay. At the same time, rain and melting snow are softening up the mountain from the outside. The result, geologists say, is a mountain gone "rotten."
Other mountains in such bad shape have erupted with deadly rage. One of them, Washington's Mount St. Helens, blew in 1980, killing 60 people. Although experts say Mount Rainier is unlikely to erupt soon, the simmering giant could cover the towns below with a major landslide.
"It's only a matter of time," says Dan Miller, a volcano expert with the U.S. Geological Survey (USGS), "before those towns near Rainier are buried."
A Hot Global Problem
So far, the most dramatic volcanic activity of the year seems to be taking place at movie theaters, where Dante's Peak and next month Volcano steam up
the screen. But real volcanoes are bubbling around the world. In Mexico the volcanic peak El Popocatepetl (pope-uh-cat-uh-petal) has lately begun to smoke and churn, threatening 500,000 people who live nearby. In Italy at least four active volcanoes are being watched, including temperamental Mount Vesuvius. In Japan 86 volcanoes are packed into an area smaller than California. Other volcanoes sputter and steam in Ecuador, Alaska, Iceland and Peru. At least 550 active volcanoes ring the globe, putting the lives of 500 million people at risk. An additional 1,000 volcanoes boil away under oceans.
"Someday, one of these mountains will erupt on a scale greater than mankind has ever seen," says Robert Tilling, chief scientist of the USGS Volcano Hazards Program. "That could be truly catastrophic."
But maybe not. The good news is that scientists can now help keep people safe. Researchers are developing ways to detect volcanic activity using satellites, sound sensors and very sensitive gas sniffers. In 1991 scientists took the pulse of Mount Pinatubo in the Philippines and correctly predicted that it was about to erupt. They persuaded officials to evacuate 35,000 people just two days before Pinatubo blew, saving thousands of lives.
High-Tech Detectives
After Mount St. Helens blew its top, the U.S. government flew into action, setting up full-time volcano labs in Menlo Park, California; Anchorage, Alaska; and Vancouver, Washington. One already existed near the Kilauea (kill-a-way-a) volcano in Hawaii.
A special quick-response force known as the U.S. Volcano Disaster Assistance Program was also created. Its members scramble to the scene of an awakening volcano within 48 hours of the first sign of trouble.
These days, satellites in space are watching our planet's volcanoes. Volcanologist Bernard Chouet works with a combination of ground instruments and space satellites. He puts more than 40 sensors at the base of a mountain. Next, he tunes the instruments to a military satellite orbiting the earth. The ground sensors listen for rumbles of materials moving within the mountain, and Chouet determines what those materials are. At the same time, the satellite locates the sensors so that a computer can pinpoint the materials' location. The system creates a nearly perfect picture of the mountain's interior.
"Volcanoes are singing when they're pressurized," he says. "I can follow that process right up to the surface."
In Alaska USGS researchers have placed satellite receivers along the sloping side of the Augustine volcano and tuned them to a satellite. Like any volcanic mountain that is filling with magma, Augustine is swelling slightly. The way the receivers move can help determine if an eruption is on the way. Researchers are using another satellite to monitor the energy given off by magma as it rises inside a volcanic mountain.
Keeping Out Of Harm's Way
Volcanologist Stanley Williams is developing a way to measure pre-eruption gases and predict just when a mountain is ready to blow. Scientists once had to climb almost directly into a volcano to measure its carbon-dioxide and sulfur-dioxide emissions. Williams and six other scientists were working in a crater in the Galeras volcano in Colombia in 1993, when it suddenly erupted. Only Williams survived. After
that awful tragedy, Williams began work on a remote gas sensor that can read a volcano's emissions from a plane flying nearby.
Volcanologists know that the only way to protect humans from an eruption is to get them out of harm's way. "Volcanoes are enthralling," says Smithsonian Institution volcanologist Richard Fiske. "You can't stop them. All society can do is learn to coexist with them."
How A Volcano Works
1 Hot liquid rock (magma) from deep within the earth carves out a chamber as much as six miles below the surface. As the magma rises, gases trapped in it expand and bubble off.
2 The gases exert tremendous outward pressure that pushes the magma upward. As the magma comes into contact with groundwater, the water turns into steam and exerts more pressure.
3 The magma and gases push through cracks in the mountain. (That's why warning signs of an eruption include higher levels of carbon dioxide, sulfur dioxide and other gases.) When the magma and gases reach the surface, the pressure is suddenly released. The volcano erupts, shooting out rocks, ash, gases and lava.
Danger Spots
Many of the world's volcanoes are clustered in the Ring of Fire, a region surrounding the Pacific Ocean. The region outlines a tectonic plate, one of
seven major movable pieces of the earth's crust. Molten rock can flow from deep in the earth into the spaces where this plate rubs against others. That's why volcanoes surround the Pacific.
Mt. Pinatubo Mud flows from Mt. Pinatubo in the Philippines are killing more people today than the mountain's eruption did in 1991
Indonesian Chain The Indonesian chain is home to at least 127 active volcanoes; Java alone has 35
Mt. Rainier Heat and water have turned parts of Mt. Rainier into unstable clay. A strong tremor could trigger a huge avalanche
Alaska & Russia Ash from Aleutian and Kamchatkan volcanoes can choke the engines of jumbo jets traveling in the nearby air corridor
Vesuvius In 1631 Italy's Vesuvius spread devastation. Today the still-explosive peak could claim 600,000 lives
El Popo Popocatepetl, near Mexico City, has had recent small eruptions. A larger one could threaten 500,000 people