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Welcome to Life Noggin.
You probably think of volcanoes as huge mountains that erupt red hot lava and kill everything
around them.
And yeah, volcanoes can do this, but that doesn’t happen very often.
There are about 1500 active volcanoes on Earth, and one erupts every week on average!
You just don’t hear about them because most eruptions aren’t that big or explosive.
See, a volcano is simply any place where material inside a planet or moon that is warmer than
its surroundings erupts to the surface.
On Earth, that material is typically ash, gas, and liquid rock known as magma, which
is called lava after it erupts.
Magma is created when rock in the Earth’s lower crust and upper mantle melts.
This molten material is less dense than when it was solid, causing it to rise above the
denser rocks surrounding it and eventually, out through fissures or vents to the surface.
The size of the eruption depends on the thickness of the magma and how much gas is trapped inside.
All magma contains gases like water vapor, carbon dioxide, and sulfur dioxide.
When the magma rises, gas bubbles are released, putting pressure on the material and helping
force it to the surface.
If the magma is thin and runny, the gases escape easily and you won’t see a huge eruption.
But if the magma is thick, watch out.
Have you ever shaken a soda bottle and given it to a friend?
By shaking it, you’ve helped separate out the carbon dioxide.
When the cap is removed, the pressure is released, and the gas tries to escape quickly.
Boom — soda everywhere.
This is how a volcano works.
If a big volcano erupts, you don’t want to be anywhere near it.
The lava can reach almost 1100 degrees Celsius and reign terror by literally raining down
hot chunks of lava.
A mixture of mud, water, and other debris, called a lahar, can flow down and bury nearby
cities.
The volcanic gases can cause difficulty breathing, increased heart rate, and death.
Even worse is the damage caused by pyroclastic flows.
These are avalanches of rock and ash up to 700 degrees Celsius that typically move more
than 50 miles an hour, destroying everything in their path.
The biggest volcanic explosion in recent history was the 1815 eruption of Mount Tambora in
Indonesia.
It expelled ash over 620,000 square miles and shot volcanic gases more than 20 miles
into the air.
Sulfur dioxide lingered in the stratosphere and reflected sunlight away from Earth.
This lowered global temperatures and changed weather patterns so much that 1816 was considered
the year without summer.
About 92,000 people died due to pyroclastic flows, a tsunami triggered by the eruption,
and famines from the weather changes.
Amazingly, Mount Tambora is just the tip of the iceberg...I mean, tip of the volcano.
There are even larger supervolcanoes.
One is right underneath Yellowstone National Park and has had three mega eruptions in the
last 2.1 million years.
If Yellowstone erupts again, it could eject about 10 times more material than Mount Tambora.
Most of the United States would be covered with ash, with Montana, Idaho, and Wyoming
likely buried under several feet of the stuff.
Volcanic gases would again affect global climates.
It would be catastrophic.
But don’t get into your underground bunker quite yet.
The probability of a giant Yellowstone eruption in any given year is about 1 in 730,000.
And scientists have set up monitors around the park to detect changes in heat that would
indicate volcanic activity.
Plus, most eruptions aren’t nearly that bad.
So don’t worry.
Just sit back and think about how awesome it is that you live on a planet with exploding
mountains.
Are you scared of volcanoes, or do you think they’re pretty cool?
Let me know in the comment section below.