The three explorers met by chance.

Stephanie Grocke 


Gabby Salazar


Ross Donihue


The three explorers met by chance at National Geographic headquarters three years ago. They were attending a meeting of scientists and adventurers. It took only a few minutes for them to realize they would make perfect partners. Stephanie Grocke was a volcanologist. Gabby Salazar was a photographer. Ross Donihue was a cartographer. Grocke wanted to tell the story of a volcanic system she had been studying in Guatemala. Soon, Salazar and Donihue were hooked on the idea, too.

An Explosive Start

In 1902, the Santa María volcano in Guatemala had a major eruption. The event destroyed the surrounding landscape. It left a huge crater in the mountainside. It also left a lot of ash and rock. Later, lava flows began erupting at the base in 1922. Over time, the lava created a group of lava domes named Santiaguito.

Pumice is a lightweight volcanic rock.

A plume of ash from an eruption rises above the clouds.

Lava domes form when sticky magma erupts from a vent. It pours onto Earth. On Earth’s surface, magma is called lava. The lava here is too thick to flow far. So, it piles up, making a large dome. Caliente was the first dome. La Mitad, El Monje, and El Brujo followed.

A Place to Study

Since 1922, there have been many eruptions among the four lava domes. They happen so often, they feel normal to those who live nearby.

To Grocke, this is the perfect place to study active volcanoes. She wanted to test a new way to check on lava‑dome activity.

Photogrammetry is a type of time‑lapse photography. It allows you to observe changes over time. She knew Salazar could help with this.

Donihue would map their expedition. He would also make infographics about the lava domes and take pictures from a drone.

Santiaguito Complex

The 1902 eruption of Santa María produced a huge crater. Over time, four lava domes formed at its base.

seismic monitoring station

Santa María

El Caliente

La Mitad

El Monje

El Brujo