It streaks like a spirit down the mountain,
this dark cloud of heat and ash
incarnate above the landscape. Doomsday,
you might call it. The very planet quakes — and yet
this tide, too, recedes. This night, too, lifts
like a curtain before the proscenium
to reveal the scenery renewed, the dense
forest growing richer through the dust.
— Matthew Kosinski
Inspired by Hot Springs, this month’s Ignite story uncovers the bright side of Earth’s volcanoes. While these magmatic mounts often strike fear into our hearts, they’re actually integral to the proper functioning of our worldwide ecosystem.
In the early 20th century, Japanese poet Yosano Akiko was having a rough go of it. An outspoken feminist and pacifist, Yosano wrote poems that frankly discussed the experience of being a woman in a repressive culture. Her boldness made her a lot of enemies, who accused her of “corrupting public morals” through her verse.1
When she needed reprieve from the slings and arrows of her cruelest critics, Yosano often turned to the hot springs of Japan, especially the baths at Shiratori Onsen on the island of Kyushu.2 It may well have been after a soak at Shiratori that she wrote one of her more famous tankas:
After my bath
At the hot spring,
As rough to my skin
As the world!3
In this poem, as in many others, Yosano contrasts the roughness of the outside world with the restorative and relaxing waters of the hot springs. She finds momentary refuge from the social order that seeks to silence her in everyday life. Paradoxically enough, she finds that refuge in a bath made possible by one of nature’s most destructive forces: volcanoes.
Kyushu is home to many hot springs. Those that are too hot for human use are called “jigoku,” or “hell.” Pictured here is Kamado Jigoku; Source: KamadoJigoku
Kyushu is a place of intense volcanic activity. The island’s hot springs — indeed, many hot springs around the world — are the direct result of this activity. WIthout the hot gas and rock produced by Kyushu’s volcanoes, there would be no heat source to yield such pleasantly warming waters.4
The Very Air Is Volcanic
Like so many natural gifts, we tend to take hot springs for granted. Yet, when you stop to think about it for a second, there’s something deeply ironic about a devastating environmental entity producing something so soothing.
Then again, maybe it only seems ironic because we humans often interpret the world in terms of absolutes: good vs. bad, friend vs. foe, useful vs. useless. Nature, however, is far more nuanced than that. Even its most terrifying aspects — a grizzly bear hulking through the woods, or magma welling up through the crust — have a part to play in keeping the ecosystem operating.
Volcanoes in particular are one of the key reasons why complex life forms are even able to exist on this planet at all.
Alaska’s Cleveland Volcano, photographed from the International Space Station. Source: Wikipedia
Take water, for example — something that virtually every living thing on Earth needs to survive. But geological evidence suggests liquid water didn’t show up on our planet until about 4 billion years ago. So how did it get there?
For years, one of the most popular theories held that water came from outer space, deposited here by comets that crashed onto our terrestrial doorstep. But there are problems with this theory. First, the timeline’s not perfect. The oldest mineral on earth, zircon, formed between 4.3 and 4.1 billion years ago through the interaction of magma and liquid water. This suggests liquid water predates the barrage of comets, which scientists believe happened around 3.9 billion years ago. Another problem: Given the amount of energy released by a comet’s impact, it’s likely that much of the water carried on any given comet would be vaporized instead of settling on the planet.5
“During volcanic eruptions, water would be released as vapor, which would condense into clouds, which in turn rained the water back down onto the planet’s surface.”
A competing theory has gained steam — pun intended — in recent years. According to this theory, water was always present in minerals in the Earth’s mantle, the part of the planet that lies between the innermost core and the outermost crust. As these minerals were melted by magma, the water would dissolve into the magma, which then carried that water to the surface. During volcanic eruptions, water would be released as vapor, which would condense into clouds, which in turn rained the water back down onto the planet’s surface.6
This same process also helped form Earth’s atmosphere, which provides the oxygen and protection life needs to thrive on land. As large bodies of water appeared on the planet, they would react to ultraviolet radiation from the sun. Through this process, oxygen molecules were released from the water and into the atmosphere. Over time, the oxygen formed ozone, which provides defense against solar radiation. With oxygen to breathe and a buffer between themselves and the sun, early single-celled ocean life was able to emerge onto the land and begin evolving into more complex organisms.7
Lava flowing during the eruption of Kilauea, a volcano on the island of Hawaii; Wikipedia
Like Living on Dry Land? Thank a Volcano
That there was land at all for the organisms to climb onto is also thanks in large part to volcanoes. More than 80 percent of Earth’s surface area, above or below sea level, comes from volcanic activity.8
In its earliest days, Earth’s surface was highly volatile, made primarily of molten rock — almost as if the entire planet were made of magma. Over time, alongside the accretion of the atmosphere and bodies of liquid water, the planet cooled, and its molten surface became a solid crust.9
New land is still created to this day, often through the eruption of underwater volcanoes. As magma comes into contact with water, it cools and hardens. Over time, as more and more eruptions occur, the magma slowly builds up a sizable surface area. As it rises upward and out of the water, it becomes the dry land we stand on.10
And volcanoes don’t just give us land — they also give us the ability to farm that land. Volcanic soils, which are made from volcanic ash and magma, are only present on about 1 percent of the world’s surface. However, this soil is so fertile that the food grown from it can support as much as 10 percent of the world’s population.11
Hunga Tonga-Hunga Ha'apai, pictured above, is one of the newest islands on Earth, formed from a volcanic eruption in 2015. While scientists are unsure whether the island will last, flowers are already growing and birds have begun to nest there. Source: BBC.com
Volcanic ash and magma are rich in nutrients like calcium, magnesium, potassium, and phosphate. As the volcanic detritus settles into an area, it is broken down through a process called “chemical weathering,” by which moisture and atmospheric gases slowly release these nutrients into the soil. Volcanic rock is more susceptible to chemical weathering than other forms of rock, so more nutrients are released faster during this process.12
Volcanic soils also help capture carbon from the climate. Through the chemical weathering process, carbon dioxide in volcanic rock is transformed into bicarbonate, which in turns gets washed into the ocean, where it dissolves into the water and stays trapped there. A team of scientists led by the University of Sheffield has recently proposed using this fact to our advantage to fight climate change. By spreading pulverized volcanic rock across farmlands, these scientists say, we can not only fertilize plants but also create a widespread system of volcanic carbon sinks. The scientists estimate this method could remove as much as 4 billion metric tons of carbon dioxide from the atmosphere per year.13
What the Volcano Said
Volcanoes have been as equally vital to humankind’s psychological landscape as they’ve been to the physical world. Since practically the dawn of mythology, humans have been telling stories about volcanoes. In the process, these ferocious figures have become purveyors of cultural memory, fluid symbols that can be used to pass meaningful messages from generation to generation. And these myths can be more accurate than modern science.
“Since practically the dawn of mythology, humans have been telling stories about volcanoes.”
Early morning clouds, not an eruption, over Nabukelevu or Mount Washington, Kadavu Fiji. Source: ZoomFiji
In an article for BBC, Jane Palmer recounts the story of geologist Patrick Nunn, who heard the Fijian myth of the chief Tanovo. Tanovo loved to walk along the beach and admire the sunset. One day, Tanovo’s rival — chief of the very real Nabukelevu volcano — used his mountain to block Tanovo’s view of the sunset.14
At first, Nunn assumed this myth referred to a volcanic eruption at Nabukelevu. According to his investigations, however, the volcano had not erupted in 50,000 years. Given that Kadavu Island, where Nabukelevu is located, was settled in 2000 B.C., Nunn thought he was mistaken. No humans would have been around to record Nabukelevu’s eruption in the mythological record.15
“The cultural memory was right, and our scientific surveys were wrong.”
Years later, ancient pottery was discovered near the base of Nabukelevu, buried under layers of volcanic ash. This new evidence proved an eruption had occurred much later than 50,000 years ago, during a time when humans did inhabit the island. As Nunn puts it, “The cultural memory was right, and our scientific surveys were wrong.”16
Humans have long used myths to preserve information, and volcano myths are particularly useful ways of recording environmental data. The natural world is subject to all sorts of physical forces. Erosion, chemical weathering, and other processes can erase nature’s tangible traces on the landscape, but myths are not subject to nature’s pressures. Volcano myths have been a critical means of sharing knowledge with future generations to help them prepare for possibly cataclysmic events they may not otherwise expect. Recognizing this fact, Nunn and many other geologists now look to volcano myths as records that contain “missing data” that can help scientists better understand the world.17
Engraving of Ilopang, a volcano in El Salvador, from Appleton's Annual Cyclopaedia and Register of Important Events of the Year 1891; Source: Wikpedia
Volcanoes Make the World Go ‘Round
It’s true that volcanic eruptions are devastating events. They can destroy people’s homes and snuff out lives. However, to think of Earth’s volcanoes as only sources of destruction would be to tell just half the story. From comforting an unfairly maligned poet to producing the air we breathe, the water we drink, and the food we eat, volcanoes have clearly done at least as much good for the world as bad.
In fact, if there’s one overarching lesson the volcano has to teach us, it’s that applying such dualistic categories as “good” and “bad” to the natural world is a mistake. The planet we live on is an intricate system, finely honed over billions of years. Every component has its rightful place, contributing in some way to the perpetuation of the whole.
Which brings us to another lesson we can learn from volcanoes: What role are we humans playing in this system? A lot of recent evidence suggests we’re tending more toward destruction than revitalization. If even volcanoes can be creative forces, then what’s stopping us from doing the same?