Looking at the Dangers

Understanding the science was only part of the team’s mission. They also wanted to share their data—not just with the scientific community—but with the people who lived in the shadow of Santa María.

More than 1.9 million people live within 10 kilometers (6.2 miles) of the active lava domes. If there is a massive eruption, that’s a lot of people living in harm’s way.

Massive eruptions can cause a lot of damage. 

While most of the eruptions are small, two dangers occur with some frequency: lahars and pyroclastic flows.

The lava domes produce a large volume of ash and volcanic rock. When water or ice mixes with these, it forms a muddy liquid that flows down the volcano. It typically follows river valleys. There are three types. “Dirty water” happens when river levels don’t rise, but water is discolored by ash. “Currents” are pulses of ash‑rich water that flow along the rivers. “Lahars” are currents of a soupy, ash‑rich mixture flowing down river valleys.

Lahars are a major hazard as this region gets a lot of rain. The mixture of water, ash, and volcanic matter can rush down river valleys and destroy whole towns.

Another danger is pyroclastic flows. They are scorching clouds of gas, ash, and rock. They flow like liquid down the volcano. They move over the ground with such speed you can’t outrun them.

Spreading the Word

Many local people have grown up with myths about the volcanic system. The team created a museum exhibit and held talks to deliver scientific information and correct misconceptions.

People began to see where some of their myths came from as they learned the science behind their unruly neighbor. To them, the lava domes are full of cultural significance. Armed with new knowledge, the people can work toward developing warning systems and other safety measures.

The team still has a lot of work to do. Analyzing all of their data may take a long time. Already the team can “see” activity that they weren’t able to catch just by looking. It is their hope to discover patterns that reveal how the volcano and its lava domes act and what changes may come in the future.

El Caliente

Santa María

This bridge is used by local people who cross it daily. But it is also one of the bridges that is frequently destroyed by eruptions.