Saturday, March 28, 2015

Why I love Earthquakes even if that might make me a terrible person

A few weeks ago, I was complaining about having nothing to write about on Saturdays. That's still sort of true, but at the time two persons gave me a topic. The first was "Life in Japan" and you can find the resulting crazy post here, It's called "Life in Japan or why I might never be an adult but I don't care"
The second topic was Earthquakes, probably due to the fact that I shared Earthquake as a facebook status several times that day. The thing is as I lost the habit to have a post on Saturdays it took me all that long to get this one done. Lame! I know! But anyway here you go, my relationship with Earthquakes.

I think I first discovered Earthquake in SVT class. For the non french person out there SVT means Science and Life of Earth and that's the sort of Equivalent to Biology class with some tectonics added to it. I'm not talking about the music here, I'm talking about: 
    Tectonics (from the Late Latin tectonicus from the Greek τεκτονικός, "pertaining to building")[1] is concerned with the processes which control the structure and properties of the Earth's crust, and its evolution through time. In particular, it describes the processes of mountain building, the growth and behavior of the strong, old cores of continents known as cratons, and the ways in which the relatively rigid plates that comprise the Earth's outer shell interact with each other. Tectonics also provides a framework to understand the earthquake and volcanic belts which directly affect much of the global population. Tectonic studies are important for understanding erosion patterns in geomorphology and as guides for the economic geologist searching for petroleum and metallic ores.
(Thanks Wikipedia)
You got it? Sounds like fun? 
Well sure it was. I was in love with plates tectonics. I was Acing every single test and I can probably explain to you why we have Earthquake so often in Japan. If you ask, are you asking? Really? 
So here you go. The planet is not a uniform ball made of dirt, surprise, surprise. It's actually pretty complicated. It's made of several layers. At the very center you have a ball of iron, pretty hot stuff. Then it's cover with magma, which is rather liquidish and viscous and hot like hell and like to go out to the surface through volcanoes. And then you have the crust. If you really want a picture to visualise it, in your hand take a ferero rocher and slip it in two. Don't eat it yet, I need to explain first! 
So what interest us today are the Earthquake and the guilty part involved are the magma, because it moves and the Crust because it's broken. 

The core of the planet is really hot so the magma at the bottom is pretty hot too, everything hot want to go up to the magma at the bottom be like:
Magma at the bottom 1 : "Hey, it's so hot in here, let's get some fresh air."
Magma at the bottom 2 : "Sure I'll go with you!" 
They both go up pushing the rest of the colder magma to the side. At the mean time the magna at the top feels rather cold so:
Magma at the top 1 : "Hey, it's so cold in here, let's get downstairs a bit, I didn't say hello to iron core for a while."
Magma at the top 2 : "Sure I'll go with you!"
They pretty much always agree with each other on the temperature. See I found you a picture to illustrate. The motion of the magma is called convection.
Now if you look closely at the picture, they called something the Lithosphere, that's what we have been calling crust all along. There are two different types of crust. One is made of basalt, it lies under the oceans. The other is the continental crust and I'm not telling you what it's made of because you don't want to know or at least it's irrelevant for the topic. The only thing you need to remember is that the oceanic crust is lucky us heavier than the continental crust. 

Are you still with me here? If not just complain in the comments.

So we have the magma moving under our feet and under the crust. So of course the crust is slipping on it. Let's analyze the possibilities of the different plaque of crust hitting each other:
1) Oceanic crust hit Continental crust.  The Oceanic crust being a lot heavier, it will go down, enter the magma under the continental crust and be liquefied by the hotness of the magma. Then the Continental crust goes up and you got mountains like Cordillera de los Andes.
2) Oceanic crust running away from Oceanic crust (yes they are scared of each other) There are a little part in between them where the magma comes up to cool down in the middle of the sea (that makes sea volcanoes, pretty cool)

3) Continental crust hit Continental crust. We got mountains, like the Himalayas! (Sorry, I haven't been there yet.)


Japan doesn't have 2 plates fighting each other under it's feet, it has 4:  The Philipine plate, the north American plate, the Pacific plate and the Eurasian plate. And like that's not even enough, part of the plates themselves are kind of unsure who they want to be with. So the Eurasian plate has the Amur plate and the Yangze plate refusing to behave the same way and so making more of a mess. And the Okhotskplates is not sure if it still wants to be part of America. 
That's 6! See the problem here?

So yes, when one decide to move it's likely to wake up the others and so they all start moving which means we end up having earthquake pretty often. At first seriously I wouldn't even notice. It's a lot of few quick shakes and now I'm like : "Hey, Earthquake!" Like I can feel them in my body.

And I really think Earthquakes are pretty cool. For a minute or the length of the earthquake everything stop. People look at each other maybe thinking how long it will last, holding their breath and suddenly everything goes back to normal. It's like a small ride of checking ground. 

Now I still have some pet peeves about the way earthquakes are described in movies.
1) Earthquakes are silent! There are no rawring coming from the depth of Earth. You won't hear the Earthquake coming for you. It's be shacking you first.
2) The house is not going to fall on your face! Ok, maybe sometimes it does if you are pretty unlucky and it's a big shake and your house is near the beach and there is a tsunami coming at you. But hey, if we talk about just shake here. During the March 11 Earthquake few years back I only had one thing falling of my shelves and  suspect that it was because it was able to roll. Of course, I saw a lot of shelve down in stores especially if you go up in the buildings. But the house won't fall on your face the instant the Earthquake starts and you'll have time to get out or stand near a wall or get under a desk. I think Earthquakes are a lot more destructive in places where people are not used to them. In Japan, it's pretty safe.

Don't freak at the Earthquake people, if you had as many people as the earth does walking on your face, I'm sure you'll want to quake them too from time to time.

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