The Volcano That Changed the World

Mount Tambora sits on the island of Sumbawa, which today is part of the nation of Indonesia. In 1815, perhaps 50,000 people lived on Sumbawa, a beautiful land of rushing streams, gentle hills, and thick jungles. Looming over the northern side of the island was Mount Tambora, a quiet mountain dotted with villages and rice farms. Nobody had any reason to suspect that the peaceful mountain was in fact a volcano, that underneath its velvety green slopes were snaking tunnels filled with lava and explosive gases. Like many volcanoes, Tambora looked like an ordinary mountain and had been dormant—asleep—for centuries. But on April 5, 1815, Tambora woke up. 

The first eruption shook the island and sent up great plumes of fire and ash. But that was nothing compared with what would come five days later, on April 10. 

Kaboom!

The volcano exploded with terrible fury, spewing out great towers of fire. A tremendous cloud of gas and ash shot high into the sky. The day turned midnight black, but the mountain glowed red as rivers of lava gushed down the slopes. The eruption went on for more than three days, a deadly storm of fire, gas, ash, and rock. In the eruption’s terrifying final stage, a wave of flames and gases swept down the mountain at speeds of 400 miles per hour. This pyroclastic surge devastated everything in its path.

Mount Tambora sits on the island of Sumbawa. Today the island is part of a country called Indonesia. In 1815, perhaps 50,000 people lived on Sumbawa. Looming over the northern side of the island was Mount Tambora. It seemed like a quiet mountain dotted with villages and rice farms. Nobody had any reason to think that the peaceful mountain was in fact a volcano. Underneath its velvety green slopes were snaking tunnels filled with lava and explosive gases. Like many volcanoes, Tambora looked like an ordinary mountain. It had been dormant––asleep––for centuries. But on April 5, 1815, Tambora woke up.

The first eruption shook the island. It sent up great plumes of fire and ash. But that was nothing compared with what would come five days later.

Kaboom!

The volcano exploded with terrible fury, spewing out great towers of fire. A huge cloud of gas and ash shot high into the sky. The day turned midnight black. But the mountain glowed red as rivers of lava gushed down the slopes. The eruption went on for more than three days. It was a deadly storm of fire, gas, ash, and rock. Finally, a wave of flames and gases swept down the mountain at speeds of 400 miles per hour. This pyroclastic surge devastated everything in its path.

The eruption instantly killed at least 12,000 people living on and around Mount Tambora. Ash and lava ruined the island’s soil and poisoned its rivers and streams. Rice paddies were destroyed. No fruits or vegetables would grow. There were no fish to catch; almost every animal had been killed. Trapped without food on their ruined lands, more than 90,000 people on Sumbawa and the nearby island of Lombok slowly starved to death. 

The eruption of Tambora in 1815 was the deadliest and most powerful volcanic eruption in human history. Its explosive energy was 10 times stronger than that of Krakatoa, history’s most famous volcano, which erupted in 1883, also in what is now Indonesia. 

And yet, incredibly, few people outside the blast zone learned about this terrible disaster. News and information traveled very slowly in 1815. The only way to get a letter (or a person) across oceans was on a sailing ship. The voyage from Sumbawa to New York or London would have taken perhaps four months.

Eventually, reports of the eruption did make it overseas, but few people paid attention. Somehow, the deadliest volcano in history was ignored by most of the world—and then forgotten. 

What people were paying attention to a year later, in 1816, was the terrible weather—snowstorms in the summer, floods that turned wheat fields into lakes, frosts that blackened millions of acres of farmland around the world. Farmers up and down the East Coast lost their crops. In Europe, farmers grew desperate. In Paris, mobs of people broke into warehouses where grain was stored, risking their lives to steal sacks of flour. In China, starving families could no longer feed their children. Floods in India triggered an outbreak of a disease called cholera, which killed millions. 

The eruption instantly killed at least 12,000 people living near Mount Tambora. Ash and lava ruined the island’s soil. It poisoned the rivers and streams. No fruits or vegetables would grow. There were no fish to catch. Almost every animal had been killed. People were trapped without food on ruined lands. More than 90,000 slowly starved to death.

The eruption of Tambora in 1815 was the deadliest and most powerful volcanic eruption in human history.

And yet, incredibly, few people outside the blast zone learned about this terrible disaster. News and information traveled very slowly in 1815. The only way to get a letter (or a person) across oceans was on a sailing ship. The voyage from Sumbawa to New York or London would have taken about four months.

Eventually, reports of the eruption did make it overseas. But few people paid attention. Somehow, the deadliest volcano in history was ignored by most of the world. And then forgotten.

What people were paying attention to a year later, in 1816, was the terrible weather. Snowstorms in the summer. Floods that turned wheat fields into lakes. Frosts that blackened millions of acres of farmland around the world. Farmers up and down the East Coast lost their crops. In Europe, farmers grew desperate. In Paris, mobs broke into warehouses. They risked their lives to steal sacks of flour. In China, starving families could no longer feed their children. Floods in India caused an outbreak of a disease called cholera. Millions died.

In 1816, not even the most brilliant scientists would have believed that these weather problems were somehow connected—that all these disasters had been caused by the eruption of a volcano few had heard of. Little was known about climate or volcanoes. But today, scientists know that volcanoes can have a major impact on weather worldwide. They have learned by studying recent volcanic eruptions, like Mount Pinatubo in the Philippines. 

Scientists monitored every phase of Pinatubo’s eruption in June 1991. It was not as powerful as Tambora’s. But the eruption was still monstrous, one of the most powerful since Krakatoa. 

Using satellites and computers, scientists tracked the volcano’s huge eruption cloud as it rose into the sky. Most volcanic clouds quickly break apart and fade away. But in a very powerful eruption, the cloud rises so high that it mixes with water and other gases in the stratosphere. It turns into a foam and remains high in the sky. Scientists observed Pinatubo’s cloud as it spread across the world. Like a layer of sunscreen slathered across the sky, the cloud blocked out some of the sun’s heat and light. Temperatures dropped, and storms became more violent. It took three years for Pinatubo’s foamy haze to clear. Tambora’s cloud would have been even bigger, its effects more devastating. Indeed, like an invisible beast, Tambora’s cloud hovered in the sky for about three years. By the time the climate returned to normal, as many as 30 million people had died from Tambora’s effects. And many more lives—like the Hoisingtons’—had been forever changed. 

In 1816, even the most brilliant scientists would not have believed that these weather problems were connected––that all these disasters had been caused by the eruption of a volcano. Little was known about climate or volcanoes. But today, scientists know that volcanoes can have a major impact on weather worldwide. They have learned by studying recent volcanic eruptions. Mount Pinatubo in the Philippines is an example.

Scientists monitored every step of Pinatubo’s eruption in June 1991. It was not as powerful as Tambora’s. But the eruption was still monstrous.

Using satellites and computers, scientists tracked the volcano’s huge eruption cloud as it rose into the sky. Most volcanic clouds quickly break apart and fade away. But in a very powerful eruption, the cloud rises so high that it mixes with water and other gases in the stratosphere. It turns into a foam and stays high in the sky. Scientists watched Pinatubo’s cloud spread across the world. Like a layer of sunscreen slathered across the sky, the cloud blocked out some of the sun’s heat and light. Temperatures dropped, and storms became more violent. It took three years for Pinatubo’s haze to clear. Tambora’s cloud would have been even bigger, its effects even worse. Like an invisible beast, Tambora’s cloud hung in the sky for about three years. By the time the climate returned to normal, as many as 30 million people had died from Tambora’s effects. And many more lives had been forever changed. Like the Hoisingtons’.

John and his family survived the loss of their crops. But they gave up their farm and moved west to Ohio. They started their trek in June 1817, traveling in an oxcart piled with their possessions. 

Tens of thousands of other New England farmers made similar journeys, all driven west by the hardships of 1816. It was one of the biggest migrations in U.S. history. Most migrants went to Ohio, Indiana, and Illinois. 

The Hoisingtons’ 1,000-mile journey took three months. John’s older sister Sabrina recorded the trip in her diary. She described the family’s meeting with Native people, long days of slogging through mud, and some enjoyable visits with friends they met along the way. They arrived in Ohio in August and were soon settled into life on their new farm. 

Meanwhile, 10,000 miles away, the volcano that had nearly destroyed their lives went back to sleep, sitting in silence to this day—until it wakes again. 

John and his family survived the loss of their crops. But they gave up their farm and moved west to Ohio. They started their trip in June 1817. They traveled in an oxcart piled with their belongings.

Tens of thousands of other New England farmers made similar journeys after the hardships of 1816. It was one of the biggest migrations in U.S. history. Most of them went to Ohio, Indiana, and Illinois.

The Hoisingtons’ 1,000-mile journey took three months. John’s older sister Sabrina recorded the trip in her diary. She described the family’s meeting with Native people and long days of slogging through mud. They arrived in Ohio in August and were soon settled into life on their new farm.

Meanwhile, 10,000 miles away, the volcano that had nearly destroyed their lives went back to sleep, sitting in silence to this day. Until it wakes again.

This article was originally published in the December 2020 / January 2021 issue.