Getting the Facts: The Volcano

Almost everybody out here has seen or heard of volcanoes.  Most of our experiences are come from movies, or pictures. Some of us may even remember making volcanoes out of soda bottles and then adding baking soda to the vinegar and hurrah!  But sadly these are not the best examples.  Anyone who has seen the movie 'Dantes Peak' for example may already know just how many misconceptions are out there.  But for those who don't remember your Earth Science classes, here a list of the wrongs and the rights about volcanoes.

Misconception:  Volcanoes only form on land

Obviously someone hasn't paid any attention in school.  And I am not just addressing all you slackers in this country.  Every American should know this is false because one of our freaking states is a volcano in the ocean.  Also, many other places prove this point too, so its not just you lazy Americans that get this wrong!

Truth: 

Volcanoes can form on land, or in the ocean.  The best example of an oceanic volcano is Hawaii.  Everyone knows that Hawaii (all of it) is formed by a hot spot under the crust that consistently releases lava.  This lava builds up on top of itself forming a bigger and bigger pile of rock.  Eventually this rock breaks the ocean surface and becomes an island.  The reason Hawaii has multiple islands is plate tectonics (Something I will discuss another time).  Basically there is a single hot spot and the plate that Hawaii is built up on is moving.  Taking a quick look at this photo (below) shows you that Hawaii had more islands long ago, but they have since shrank back into the ocean thanks to erosion.

Another point to add is the mid Atlantic ridge.  This is a volcanic ridge that runs along the middle of the Atlantic ocean.  Although there is no visible signs of volcanoes on the surface, under the water there are little volcanoes spewing lava onto the ocean floor and actively pushing Europe away from North America.

Misconception: Volcanoes only form in Hot Climates.

Yeah haven't you heard this one before?  I sure have.  It's like everyone assumes that since volcanoes release hot things, they must be in hot places.  That makes perfect sense.  But its also totally wrong.

Truth:

Volcanoes can form in any climate, as long as there is enough heat to melt rocks and push it up to the surface.  A perfect example of this is Iceland.  In Iceland even in the summer your average high is in the 50's.  This is certainly not a hot climate.  So where does this misconception come from?  I honestly don't know.

Misconception: Volcanoes are randomly located all over the Earth's surface.

Sure I get it know.  I told you that volcanoes can be in the ocean.  Then I told you that volcanoes can be in cold climates.  So now you're all like, I got this, volcanoes can be anywhere I can think of!  Well no.  Although both of those things earlier are true, volcanoes are still limited to specific places.

Truth: 

Volcanoes form along plate boundaries and hot spots.  I have mentioned earlier that plate tectonics played a role in how Hawaii was formed.  I should also note that plate tectonics is responsible for MOST volcanoes.  If you look at the map below you will see a bunch of red triangles.  Each one of those triangles represents a volcano.

Now look at this map of plate boundaries...notice anything?

Some of those same plate boundaries are surrounded by volcanoes.  Yet others have none at all.  So what gives?  Well I will spare you the entire lecture on plate tectonics (for now) and say this.  Most of the volcanoes on that map are at convergent boundaries.  Meaning one plate is being pushed against another.  As one plate gets pushed it begins to sink down and slide under the other plate.  As a plate sinks it is exposed to more heat and pressure.  This helps melt the rocks, which in turn are pushed upwards and form a volcano.  So aside from a few hot spots volcanoes are anything but randomly placed around the world. 

Misconception: All Volcanoes Erupt Violently and/or Straight up Through the Top Vent.

This one is probably the most common misconception out there.  But I can see why.  Movies and pop-culture always show volcanoes erupting in this fashion.  It looks cool and we love to think about how awesome the Earth is.  I mean who wants to think that a volcano can just leisurely pour out some rocks and call it a day.

Truth:

Some do, some don't.  This video contains footage of a typical 'eruption' from Hawaii's big island volcano Mauna Loa. This is not to say that volcanoes don't go spewing molten rock into the sky...its just not necessarily the only thing that they do.  

Misconception: Humans sink into lava.

This one is a bit of a bonus. But we see this all the time.  In any movie where someone goes into the volcanoes cone you tend to see red hot lava, a guy falling in, and a guy just sinking into the bubbling lava.  So would a human body really do that?

Truth:

As this video proves, no.  

See humans are composed of 70% water.  And what happens if you rapidly heat water?  It turns into steam, which occupies a larger volume of space than water does.  So what do you get?  Not a slow motion sink into hot lava, but a pretty spectacular explosion. Then after the steam escapes you still have all the fleshing parts to burn up.  

So I hope that you leave today knowing not to trust everything you see and hear about volcanoes.  They are pretty damn cool though, so please go and check out more about them.  It never hurts to learn a more about something as cool as this.  If you feel that I have missed any major misconceptions please feel free to let me know.