The day was April 5th, 1815, before the Industrial Revolution began. The majority of the population were farmers, raising crops to feed themselves and others. But farmers depend on good weather, with abundant rain, sunlight and warmth. This year, they wouldn’t have enough of these key weather elements to ensure a good crop. Food prices would rise and many would go hungry. Thousands would die around the world.
So, what happened on April 5th, 1815? The largest volcanic eruption in human history, registering a Velocity Explosivity Index or “VEI” of 7 out of 8. By comparison, Mount St. Helens, the largest volcanic eruption in recorded American history, rated a VEI of merely 5.
When volcanoes erupt, there’s more going on than spewing forth hot lava, although it is that lava which receives all the attention. Copious amounts of gases and ash are ejected into the upper atmosphere, causing even more serious problems than the lava does. Lava is merely a local event, while the fine ash from a volcano can travel around the world, taking months to come back down to earth.
The two-week long eruption of Mount Tambora in Indonesia spewed 19 cubic miles of ash into the atmosphere. By comparison, Mount St. Helens releases ¼ of a cubic mile. Much of that ash, especially the larger particles, came down within a few miles of the volcano, dropping a layer of ash 12 feet thick over an area one hundred miles on a side. But it was the finer ash which caused widespread problems, for it went higher into the upper atmosphere, but stayed up there, causing a volcanic winter.
Ash was so thick in the ocean, that shipping had to struggle to push through it. Several tsunamis were also caused by the eruption, causing widespread damage and destruction.
Opinions vary, but climate scientists state that the overall temperature of the earth lowered by between one and three degrees Celsius. But that figure is an average. In Europe and New England, weather patterns were severely affected, causing heavy snow on June 6th, 1816. Drifts of 18 to 20 inches high were recorded in Philadelphia.
Tons of fine ash particles were blown into the stratosphere, where they blocked the sun’s rays. In addition to the ash, there was sulfur dioxide, which combined with water vapor to create sulfate aerosols that reflect the sun’s rays, adding to the problem caused by the ash.The colder temperatures and lack of sunlight affected crop growth. Between the two, there wasn’t enough sunlight to warm the earth or for plants to use to grow properly. But it wasn’t just the newly founded United States that was affected. Wet conditions in Europe and Asia rotten many crops in the field, before they could mature to harvest.
These widespread agricultural problems caused countless people to die of starvation. There is really no accurate count as to how many suffered and died for lack of food. But that wasn’t the only thing that people were struggling with, as disease flourished in the altered climate. It is quite likely that the Cholera epidemic of the 19th century owes its success to the Mount Tambora eruption.
While the impact of the volcano’s eruption were widespread and devastating, they were also somewhat short-lived. By 1817 temperatures returned to normal and the volcanic winter was over. But for many people, the effects of that eruption changed their lives forever.
Could it Happen Again?
There are still approximately 1,500 volcanoes in the world today, not counting the belt of volcanoes on the ocean floor. Many of those volcanoes are located along the Pacific Rim, in what is known as the “Ring of Fire,” a region of geologic instability, due to converging plates.
As the Mount Tambora eruption proves, even those volcanoes on the other side of the world, could have a devastating effect on us. But those aren’t the greatest danger, as here in the United States, we have 169 volcanoes which scientists consider to still be active. The majority of those are located in Alaska, the Northwestern part of the country and Hawaii. Eruptions in Alaska happen virtually every year; but they go largely unnoticed, due to the low population of Alaska.
However, the biggest and most dangerous American volcano isn’t in these areas; it’s in northwest Wyoming . The Yellowstone Supervolcano, which scientists have been warning us is overdue for an eruption, sits in the midst of one of the country’s top vacation destinations. Yet underneath the ground, the heat which causes all the beauty that people go there to see creates a very dangerous situation.When the Yellowstone Supervolcano finally does erupt, it could rival Mount Tambora for its destructive power. There is really no way of knowing, until it happens. While scientists know and can measure some of the precursors to an eruption, that only gives a few day’s notice. There is no known was of predicting volcanoes beyond that narrow window.
It is estimated that an eruption of the Yellowstone Supervolcano would spew ash for over 1,000 miles, with the first 600 miles from the volcano receiving enough ash to kill crops and even animals. People living within a couple hundred miles of the volcano would have little chance of survival, while those living farther away would survive, but only to struggle though the volcanic winter that the eruption would cause.
A large part of the ash that would be spewed out of the volcano would land in the Midwest, blanketing the Breakbasket of America, the country’s and the world’s most productive farmland.
While the actual chances of an eruption are extremely low in any one year, Yellowstone will eventually erupt. When that will happen is anyone’s guess, and has been the source of much apocalyptic writing. How severe is another guess, as the volcano could have a much smaller eruption, rather than the massive one that everyone expects. In either case, those who are closer will obviously feel the heat much more than the rest of us.
Should a massive eruption occur in Yellowstone, there is the possibility that it could rival Mount Tambora or even surpass it. Should that happen, we might find ourselves in a volcanic winter that lasts several years, causing incredible damage and millions of deaths.
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