Around the world, over 600 million people live near one of 1500 active terrestrial volcanoes. Who's keeping them safe from potential future eruptions? The women and men who study these gas-and-ash-and-lava belching windows into the center of the earth: volcanologists.
You might not be sure what volcanologists do or why they matter—especially if you live thousands of miles away from one of these fiery mountains. So, Mental Floss went searching for answers from four volcanologists working in various capacities around the country, who shared their experiences in the field, under the ocean, and gazing far out into space.
1. THEY STUDY EVERYTHING FROM MAGMA COMPOSITION TO VOLCANIC GASSES AND BEYOND.
"When I tell people what I do, 95 percent of the time they ask, 'What is that?'" says Arianna Soldati of the University of Missouri, who researches lava flows.
Volcanology is the study of how volcanoes form, what they're made of, and what they eject, among other areas of research. Many volcanologists have degrees in geology; some, like Soldati, are physical geologists, collecting samples on site and then analyzing them to figure out their composition. Others are geophysicists who study tectonic plates and their role in volcanic eruptions and earthquakes. Geochemists and petrologists study volcanic gasses and minerals, and geodesists look at deformations on and around volcanoes to figure out if magma is pooling up underneath them. All these disparate disciplines work together, Soldati says, to "understand how the planet works, so we can understand how eruptions work."
2. THEY WORK WITH OTHER VOLCANOLOGISTS AROUND THE GLOBE IN THE NAME OF SAFETY.
Jacob Lowenstern is Chief of the Volcano Disaster Assistance Program at the United States Geological Survey (USGS), a government agency that monitors our country's 169 active land volcanoes, largely via observatories in Hawaii, Alaska, Washington, and Oregon. But it also offers assistance and training to volcanologists in other countries because, as Lowenstern points out, an active volcano system respects no human borders. The program helps keep people and animals safe from the destruction wrought by lava flows, mudslides, and gas: When eruptions happen, localities issue alerts based on data from USGS.
Underwater volcanoes can create shipping hazards, like floating chunks of pumice, but a land-based volcano can create serious chaos worldwide. When Iceland's Eyjafjallajökull erupted in 2010, its miles-high ash cloud grounded aircraft to and from Europe and Britain for about a week. "We didn't even know what concentration of ash it was safe to fly through, because no one had studied it before," Soldati says. (They do know now, although the answer depends on how long the aircraft is aloft [PDF]). Back when Tambora erupted in Indonesia in 1815, it kicked off the Year Without a Summer, as ash circled the globe and blocked out the Sun, resulting in crop failures, famine, and a total of 100,000 human deaths. "At some point, something truly global [like that] is going to happen again," Lowenstern says. Volcanologists aim to be prepared.
3. SOME OF THEM WORK UNDERWATER ...
An estimated 80 percent of eruptions happen beneath the oceans' waves. It hasn't been easy for volcanologists to research them—for starters, there was no comprehensive map of the ocean floor until just a few years ago. And not being able to see a volcano that's 3000 feet underwater makes observation … challenging. Historically, scientists mostly monitored underwater volcano activity using fickle, battery-operated equipment installed on the seafloor, which could only store (rather than transmit) data. The first complete footage of an underwater eruption wasn't captured till 2009.
William Wilcock says technology has finally caught up to the thirst for information. He studies the Pacific Ocean's Axial Seamount—the most active volcano in the Northeast Pacific—via the Cabled Array ocean observatory, 550 miles of fiber-optic cable equipped with sensors that allow scientists to to monitor the Juan de Fuca ridge off of Oregon's coast. Using the array, they can monitor the chemicals and temperature in the water column, measure the volcano's magma chamber, and keep tabs on earthquakes, which could signify an eruption.
The array sends underwater volcanologists data in real time—fast enough that they can sometimes deploy autonomous vehicles for a closer look at eruptions as they happen. In April 2015, the project's team was able to witness an entire eruption of Axial Seamount from start to finish, leading to “the most detailed observations ever made” of an undersea volcano, as Wilcock told The Washington Post. The data they gleaned helped them understand how the seamount's caldera falls during eruptions and then reinflates with gases and magma before reaching a particular threshold, at which it erupts. Understanding how that inflation works is important for land volcanoes too, which is part of why data from the array is posted on the internet for scientists around the world to use.
4. ... AND SOME STUDY VOLCANOES IN SPACE.
The only scientist NASA sent to the moon was geologist Harrison “Jack” Schmitt, who flew on Apollo 17. (All of the other astronauts were military men-turned-NASA test pilots.) Schmitt—who was actually allergic to regolith, a.k.a. moon dust—helped prove that the moon was once volcanically active. This fact makes NASA's Alex Sehlke incredibly proud—and envious. He's a volcanologist who conducts research in Idaho's Craters of the Moon National Monument in preparation for the agency's planned return there in a few years. Craters of the Moon is geologically similar to our actual moon, in part because it was formed by lava erupting from the middle of the continent, not a juncture where two plates meet; moon volcanos were likely formed in a similar fashion, since the moon is covered, basically, by a single giant plate.
Volcanologists like Sehlke usually play supporting roles in space exploration. They test equipment and speculate about how, say, Craters of the Moon's lava tubes are like those under the surface of the actual moon and might make for a good base of operations. "Imagine looking at the surface of the moon [from Earth] when you're planning a mission and saying, ‘Hmm, looks alright,'" Sehlke says. "But there are questions we need to answer before we go—maybe the terrain is treacherous."
They may also offer guidance from mission control to astronauts (often about areas that look like they might be interesting to explore), and analyze data from probes—like the first images of an ice volcano erupting on Saturn's moon Enceladus, captured by the Cassini spacecraft in 2005.
5. SOME OF THEM ARE LOOKING FOR THE BEGINNINGS OF LIFE.
Hydrothermal vents—openings in the seafloor where water enters, becomes heated, then spurts back out—support a lot of weird microbes that Wilcock says may be similar to the first organisms that ever existed on our planet. Studying them and the conditions that created them may help us understand how to look for life on other planets and moons—one of NASA's primary objectives. But Sehlke and others are also looking for life by scanning data from probes exploring our solar system: "Wherever volcanoes sit, on Enceladus or elsewhere, there is heat or fluids that maybe provide the necessary environment for microorganisms like the ones we know on Earth," Sehlke says. Volcanoes like these "give us the highest chance of finding life" out in space.
6. THEY ALSO WANT TO UNDERSTAND HOW TO SUSTAIN THE LIFE WE ALREADY HAVE.
While volcanoes created Earth's original atmosphere by emitting the carbon dioxide and nitrogen necessary for life, other volcanic gasses, like sulfur dioxide, increase the ability of our current atmosphere to retain heat [PDF]. "Learning how these things balance out is hugely important to understanding our future" on the planet, Soldati says. That's why new studies are looking at the links between volcanic activity and climate change, and how they may exacerbate each other.
Some volcanologists are particularly concerned about Iceland, where melting ice caps may be releasing pressure on magma chambers, contributing to more—and more explosive—volcanic eruptions in the future. The effect of the reduced pressure is similar to how “the cork of a champagne bottle flies into the air when it has loosened sufficiently,” geophysicist Magnus Guðmundsson told Hakai magazine. Another new study urged those making models of our climate future to include volcanic eruptions as a variable, which they find are under-sampled in such models but can have big effects on temperatures, sea levels, global radiation, and ocean circulation, among other key elements of the climate.
7. THEY GET TO USE A LOT OF COOL EQUIPMENT ...
Volcanologists use a lot of very high-tech equipment in their line of work. Seismometers measure earthquakes on volcanic slopes. Infrared cameras measure the heat of lava flows. Correlation spectrometers measure the amount of sulfur dioxide in the air, which is released when magma is rising to the surface (and so can signal when a volcano might be ready to erupt). Tiltmeters measure, literally, the tilt of the land around a volcano. If instruments like these, having been mounted on a volcano, fall apart during an eruption, "we sometimes use helicopter drops to put new equipment on the ground," Lowenstern says. More and more, though, volcanologists monitoring land volcanoes rely on equipment mounted on aerial or space-based unmanned craft, "so we don't put people in harm's way." This includes technology called InSAR (Interferometric Synthetic Aperture Radar), which, from a satellite in space, can measure a volcano stretching and contracting. That helps scientists keep tabs on just what the magma inside a volcano is doing—and whether it's about to come up.
8. ... BUT ONE OF A VOLCANOLOGIST'S MOST IMPORTANT TOOLS IS A ROCK HAMMER.
Out in the field, Soldati says, her most important tools are her notebook, for jotting observations, and her steel rock hammer, which she uses both to chip away at rock and to gather samples of molten lava. To grab a sample, she swings into the lava with the pointed end of the hammer, then drops the molten material—which is around 2000°F—into a pail of water; quickly cooling the lava in this way turns it to glass (slow cool it, and it becomes rock), which she transports back to the lab.
Once there, Soldati relies on machines like a concentric cylinder viscometer, which melts lava samples so she can measure their viscosity—which tells her how explosive a volcano's eruptions are. Less viscous lava trickles out of a volcano, while more viscous, and hence more explosive, lava can blow out the whole side of a mountain, sending burning lava, rocks, and other debris flying.
9. IT DOESN'T LOOK LIKE THE MOVIES.
One thing field volcanologists almost never use: those clichéd silver flame-proof proximity suits. "They're heavy, and since you usually have to walk hours to get to your field site, no one wants to carry all that weight," Soldati says. Besides, "heat is almost never the hazard that matters in the situations in which we work," writes Aaron Curtis, a volcanologist working at NASA's Jet Propulsion Laboratory. (You have a greater chance of "being hit by ballistics, or getting gassed," he notes.) "The reason you see those suits so often is that they look really cool on TV."
So what do they wear? Jessica Ball, a Postdoctoral Fellow at the U.S. Geological Survey, writes that "sturdy boots, hard hats, work gloves, rip-resistant clothing with long sleeves, and sunglasses or safety goggles are pretty standard, and I will add a gas mask if I’m going to be in an area with lots of fumes. Also, sunscreen is always important, because I’m often out in the sun all day."
10. SOME OF THEIR WORK IS DANGEROUS IN UNEXPECTED WAYS.
Lava and flying debris aren’t the only hazards during fieldwork. Tina Neal, a volcanologist with the USGS, has reported that she’s had several encounters with bears while working at Ukinrek Maars in Alaska. She also says, "I think the aircraft work of volcanologists is as dangerous if not more so than the active volcanoes we visit and study." Geologist Christina Heliker has described the most fearful moments during her time on staff at the Hawaiian Volcano Observatory as being those that involved flying in a helicopter over continuously active Pu`u `O`o. Once, while trying to return to camp after mapping lava flows, “It was almost dark, and we were sandwiched between an incandescent field of `a`a [lava] and this thick layer of clouds that were glowing orange from the reflected light of the lava,” she told an interviewer. “I was plenty relieved when the pilot decided to give it up and fly out to somewhere else.”
11. THEY WANT YOU TO KNOW: VOLCANOES AREN'T ALL BAD.
Volcanologists aren't drawn to their work only because of the destructive power of their research subjects. "[Volcanoes] also have a positive impact on our life," Soldati says. She points out that volcanoes fertilize the soil—some of the most productive crops on our planet are grown in mineral-rich volcanic ash. They also create new land; the Hawaiian volcano Kilauea has added 500 acres to the Big Island since 1983. So don't say volcanoes never give back.