There is a lot of hot weather in various parts of the world. It is put
down to global warming or other things. But it is a long while since we have
had a really big volcanic eruption. This refers to 1816 but there was another
in 1883.
Perhaps we are overdue for a big one to cool things down?
HOW A VOLCANO ERUPTION WIPED AWAY SUMMER
The biggest volcanic eruption ever recorded in human history took place nearly
200 years ago on Sumbawa, an island in the middle of the Indonesian
archipelago. The volcano is called
Tambora, and according to University of Rhode Island volcanologist Haraldur
Sigurdsson, the eruption is one of the most overlooked in recorded history.
Tambora's explosion was 10 times bigger than Krakatoa and more than 100
times bigger than Vesuvius or Mount St. Helens. Approximately 100,000 died in
its shadow. "The eruption went up
about 43 kilometers into the atmosphere. That is about 30 miles — much higher
than any airplane fly[ing] today — and emitting a volume that is about 100
cubic kilometers of molten rock in the form of ash and pumice," Sigurdsson
says. "That volume is by far the largest volume of any volcanic eruption
in life on earth."
Global Cooling
But it was the enormous cloud of gas — some 400 million tons of it —
released by the eruption that produced the "year without
summer." When the gas reacted with
water vapor in the atmosphere, it formed tiny little droplets of sulfuric acid
that became suspended in the stratosphere, creating a veil over the Earth,
Sigurdsson says.
This veil of gas acted like a mirror, bouncing radiation back into space
and decreasing the amount of heat that reached the Earth's surface, causing
global cooling, he says. Of course, no
one knew that at the time, and few people know about it even now. It wasn't
until the early '80s, Sigurdsson says, that he caught the Tambora bug. In that
decade, researchers taking core samples in Greenland's ice made an amazing
discovery.
"You drill down through the ice, and you can count the rings just
like in a tree. And people started doing research on the layers, and they found
there was a whacking great sulfur concentration at one particular layer:
1816," Sigurdsson says. "That
was first evidence that Tambora had global reach … and that it was
unstudied," he says, adding, "We needed to get much more info on what
really happened here."
The Year Without Summer
The year after Tambora erupted, Europe was trying to cope with the
aftermath of the Napoleonic Wars. There
was a mass demobilization of soldiers flooding into the labor market.
Patrick Webb, a dean at Tufts University's Friedman School of Nutrition
Science, describes the socio-political climate after the wars. "You had economies disrupted,
infrastructure damaged, governments in limbo," Webb says. "And so the
conditions were already ripe for something to go wrong." And something did go wrong in 1816, known as "the
year without summer." Temperatures dropped, crops failed and people
starved.
"Hundreds of thousands of people died. People were reduced to
eating rats and fighting over roots," Webb says. "Most of these
people were killed by epidemic disease, [such as] typhus and other things
related to starvation. They simply couldn't find enough food." In America, New Englanders saw snow well
into the summer — the average temperature in July and August was 5 to 10
degrees below normal, according to Webb.
A Bad Vintage Year
Even the wine from 1816 was bad.
Alain Vauthier, who owns one of the oldest vineyards in Bordeaux,
France, keeps a fair bit of wine from each vintage in the cellar. He has an
impressive collection, which stretches back to the beginning of the 19th
century, but there are only a few bottles from 1816. Vauthier says that's as it
should be.
"It is not a good vintage," Vauthier says. "It is a bad
time, bad weather, bad summer."
Daniel Lawton is the owner of Bordeaux's oldest wine brokerage house.
His assessment of the 1816 vintage is even less charitable. "Detestable, you understand?
Horrible," Lawton says. "A quarter of the normal crop. Very difficult
to make good wine. Just a terrible year." All of this was triggered by a
volcanic eruption that happened on the other side of the world.
Reading the Layers of Earth
For more than two decades, Sigurdsson, the volcanologist, has been
gathering information from the Indonesian island. His first trip to the
volcano, Tambora, was in 1986, and his most recent trip was just a few months
ago. His task is made easier, he says, by the scrupulous record keeping done by
the earth itself. The layers of the soil on the island are not unlike the
layers of ice in faraway Greenland.
"Each layer [is] like [a] page in [a] book. These layers are really
a graphic representation of the eruption," Sigurdsson says. "They are
drawing out for us, writing down for us, the history of the volcano. And they
don't lie." While he was digging, Sigurdsson discovered something else:
artifacts and remains carbonized when Tambora erupted. He calls his excavation
site "The Lost Kingdom of Tambora" — a find he also refers to as
"The Pompeii of the East."
"I have studied deposits in Pompeii and Herculaneum, from the great
destruction of Vesuvius in 79 A.D. [It's] the same mode of destruction, the same
mode of death. But [the] difference here [is] that the human remains are much
more carbonized—almost entirely carbonized," Sigurdsson says.
"The bones are a piece of charcoal," he says. That tells
scientists that it was a much bigger explosion — with much higher
temperatures. The explosion was hot
enough to melt glass, and it happened so fast, Sigurdsson says, that people
living on the island had no chance to escape. The carbonized remains of one
woman recovered at the site confirm this.
"She is lying on her back with her hands outstretched. She is
holding a machete or a big knife in one hand. There is a sarong over her
shoulder. The sarong is totally carbonized, just like her bones,"
Sigurdsson says. "Her head is resting on the kitchen floor, just caught
there instantly and blown over by the flow."
The Lessons of Tambora
All the big volcanic eruptions — Tambora, Krakatau, Pinatubo — have
ended up cooling the Earth, causing temperatures to drop.
And that, Sigurdsson says, has some people thinking about replicating
the Tambora effect in an effort to slow global warming.
"People have proposed that we induce artificial volcanoes by
bringing sulfur up into the stratosphere to produce this effect,"
Sigurdsson says.But, he warns, "Do you want to counter one pollutant with
another one? I don't think so. But that's been proposed."
Still, Sigurdsson thinks that lessons from eruptions like Tambora can be
applied to models used to study global climate change.
Global warming is viewed by many as the most pressing, most dangerous
threat. But Sigurdsson warns that catastrophic climate change might come from
an unexpected, yet familiar, direction.
"Somewhere on the Earth, with[in] the next 1,000 years, there will be
a comparable eruption. And we'd better be aware of the consequences," he
says.
He notes that another giant volcanic blast would release large amounts
of gases, creating interference in the atmosphere that could cause major
disruptions in telecommunications and aviation.
Sigurdsson hopes to study and learn more about Tambora when he returns
next year.