Yellowstone – Super
Volcano In The Heartland
By James Donahue
Many of us have had the privilege of visiting Yellowstone National Park, a vast wilderness
in the mountains of Wyoming that offers lakes, rivers, geysers, hot bubbling springs, deep gorges, wild buffalo, moose, elk,
bear and breathtaking scenery.
Of all the
national parks in the United States, Yellowstone is probably the most popular. And if geologists and other scientists are
right, it may be among the most dangerous. That is because it rests about 125 feet directly over a hot bubbling cauldron of
lava linked to what is believed to be one of the largest volcanoes in the world.
Almost the entire park hides
a huge magma chamber located just below the surface. The steam vents, the hot bubbling mud lakes, the steaming pools of clear
water and the geysers, including Old Faithful, are all caused by a constant release of pressure from everything going on below.
Experts refer to Yellowstone
as a “Super Volcano.” They have determined that it erupts once every 700,000 years, and when it does, it sends
enough molten lava, rock, steam, smoke and ash shooting for miles into the atmosphere to kill every living thing for hundreds
of miles in every direction, block out sunlight all over the Northern Hemisphere, and affect not only the climate but all
life, possibly all over the world, for months if not years.
Experts say the last major eruption occurred about 640,000 years ago. Diedtra
Henderson of the Denver Post once wrote that geologic forces have been active at Yellowstone for millions of years. At least
three different eruptions have created mountains and erased landscapes over time.
A research team from the University of Utah recently reported to the American
Geophysical Union during a meeting in San Francisco that the volcano’s cauldron is much larger than it was
once believed. Professor Robert Smith said the caverns of molten lava stretches over 55 miles wide and contains from 200 to
600 cubic km of molten rock.
It is a giant monster lying
quietly. No one knows when it might erupt. But research teams are keeping a constant vigil, recording temperature changes
and other signs of possible activity.
Alarms were sounded about ten years ago when the water temperature at one hot pool rose about
20 degrees, and park officials discovered a bulge on the lake floor that rose 100 feet and stretched the length of six football
fields. They said the floor of the lake was acting like a lid on a pressure cooker. The concern then was that a hydro-thermal
explosion could occur at any time.
Not only has the surface remained elevated, but there has been a sudden rise in the release of Helium-3, a rare
type of Helium that is known to be present before a major eruption.
Yet another indicator that something is afoul at Yellowstone
this spring . . . herds of bison have been seen running along public highways, all going in the same direction. We assume
it is away from the core of the volcano.
The park area also has been the scene of many minor and a few major earthquakes in recent years.
A 7.5 quake in 1959 killed over 28 people, caused $11 million in damage, and a landslide blocked the flow of the Madison River
and created what is now called Quake Lake.
Science writer Natalie Wolchover addressed the Yellowstone threat in a recent article. She
says we don’t need to worry because “a rough estimate based on geological records indicates there’s a 1-in-10,000
chance of a ‘supereruption’ at Yellowstone during our lifetimes.”
Wolchover calculates that if the volcano does blow
and spews over 1,000 cubic kilometers of magma, it would be enough to cover most of North America in a blanket of ash. The
damage would be worse in a 2,000 mile radius but beyond that the ash blanket would be at least a trace.
She quotes Stephen Self, director
of the Volcano Dynamics Group of Open University in the UK. He said the worst problem would be the ash hanging in the air
for days after the eruption, making it difficult for people and animals to breathe. “And that blanket of ask covering
the country would smother vegetation and pollute the water supply, quickly leading to a nationwide food crisis. A lot of people
would perish,” Self said.
The ash cloud and sulfur gas would wrap around the entire world, casting the planet in shadow and altering the
very chemical composition of the atmosphere for at least a decade. But if there is enough natural rainfall to clear the ash
off the land, new vegetation will start to grow about 10 years after the eruption.
Yellowstone’s super volcano probably can't
wipe out all life on Earth. But if it blows, the impact will certainly mean a significant reduction in population everywhere.
It would change our lives as we know them for a very long time.