A trio of explorers sit atop Guatemala’s Santa María volcano, looking down on one of the world’s most active lava-dome complexes. They’d climbed 12,375 feet (3,772 meters) of steep terrain, lugging cameras, tripods, tents, and enough water for the entire expedition strapped to their backs. Ready to begin their research on the formation, they’d set up their camp at the volcano’s summit.
Santiaguito, a complex of four lava domes—round mountains made of viscous lava—lies at the base of the volcano. Since 1922, there have been small but nearly continuous volcanic eruptions from the lava domes, expelling jets of gas and ash. In November 2017, Stephanie Grocke, Gabby Salazar, and Ross Donihue—all National Geographic explorers—set out on a month-long expedition with local guides and tourism police to study these active volcanoes, test a new method to monitor lava dome activity, and develop methods for predicting eruptions. (See Why a Volcano Has Erupted Almost Every Hour for 94 Years)
On a mission to collect data about volcanic behavior, the team took a multilayered approach, blending scientific and media tools used by the three explorers: a volcanologist, cartographer, and photographer/filmmaker.
“Santiaguito is truly a great natural laboratory for doing this expedition,” said Grocke, a volcanologist. During the expedition, Grocke used cutting-edge photogrammetry techniques. “I was doing ground-based, time-lapse photogrammetry, which involved taking nearly continuous time-lapse images of the surface of the active lava dome,” said Grocke.
To accomplish this, she set three cameras with telephoto lenses and radio receivers on tripods at three different locations around the region. She triggered the cameras remotely using a transmitter so each one would be taken simultaneously from a separate vantage point. “We can bring all those photographs together into a time-lapse, which will be used to help track and quantify the surface motions of the volcano,” said Grocke.
She’ll use those photographs to create a 3D digital elevation model and reconstruct the activity of the volcano. “I did this before with [my academic advisor], but we perfected this method with the expertise from Gabby and Ross,” Grocke said.
For nearly five days, the team worked together to run the cameras. The set-up and maintenance was difficult and the group worked constantly, through total darkness and high winds.
“We were camped out on the edge of the volcano with all cameras pointed at the most active lava dome, called El Caliente, which erupts quite frequently. It’s part of the Ring of Fire and is going through an active cycle now,” said Donihue, a cartographer specializing in map-based storytelling. “The Ring of Fire is essentially this area where plates are colliding and creating this subduction zone where one plate is going beneath another and creating these rifts.” (Related: Learn How Volcanoes Work)
Donihue joined the team in Guatemala during a break in his graduate school program. “Before going, I had some concepts in mind, downloaded some base data, and identified the perspective to show the complex as a whole and the anatomy of the volcano.” To add to that information, he took GPS readings and used a drone to collect data and take aerial photographs. “My main duty was to get the maps and infographics done,” Donihue said.
The team hopes to learn how the dome reacts before, during, and after an eruption—information that may be helpful in predicting eruptions. “If we can improve our understanding of future volcanic activities then we can give people more warning,” said Donihue.
Salazar, a photographer and videographer, documented the expedition by taking thousands of photos and recording the group’s activities, but she was also crucial in the scientific data collection. “Her expertise as a photographer helped with the science too. By getting better images, setting up the cameras at night and in the daytime, she helped us collect better data,” said Grocke.
The team gathered the data and images they needed after summiting the volcano twice, but they weren’t finished with their work. They wanted to share what they’d learned with the people living in the shadow of the Santa María volcano, so they created and installed a photo exhibit highlighting life near an active lava dome.
Nearly 1,259,600 people call the 18.6 miles (30 kilometers) around the volcano home, according to a report by the Smithsonian Institution’s National Museum of Natural History Global Volcanism Program. “For locals, this volcano has been erupting in their backyard for over ninety years pretty continuously,” said Grocke. “The photos tell the story about what it’s like to live with active volcanoes, plus the benefits and hazards posed by volcanic activity.”
“Eruptions can happen in Guatemala that can be very devastating and we can’t yet predict or forecast what is going to happen. We were there as a reminder and educational tool, trying to instill a general awareness,” Grocke said.
The photo exhibit was donated to El Instituto Guatemalteco de Turismo. "One of my favorite parts of the exhibit was watching Stephanie answer questions about volcanoes using the photos and infographics—the audience was fascinated by her responses and the visuals helped facilitate their understanding of many complicated concepts, including plate tectonics and volcanic hazards," said Salazar.
Having returned from the expedition, the team has yet another task: analyzing the data, creating a 3D model, and hopefully helping the community predict these eruptions.
“The easy part’s over, and now we need to figure out how to analyze the data. Since the technology is sort of new, so is the data processing that comes after collecting the data. Right now, we are trying to get the most out of the data we have, so we can create 3D elevation models,” says Grocke. The team plans to compare their most recent images and data to information Grocke collected two and four years ago. Through this analysis, they hope to closely monitor the domes’ changes over time. “It’s a really dynamic, evolving system and we are starting to recognize cycles of how the volcano inflates and deflates,” she says. “By speeding up the process through time-lapse photography, we can start to see those changes that are occurring before eruptions.”
The end goal is both scientific and humanitarian. She explains, “We are trying to get a better idea [of] when the next big eruption may happen.”
Lauren O'Brien is a digital news writer at National Geographic, covering topics related to culture and exploration.