A cryptic title I know though there is a point to it being vague lots of things cause shaking. If you are shaking then well I can suggest you should stop drinking so much coffee and sleep instead... after reading the rest of this. of course you could just be cold or nervous or something boring like that though that's not really what this is about.
As a citizen of Christchurch New Zealand I can safely say I have felt an earthquake or two in my life well thousands really to be honest. what causes them though? well here is a quick and simple explanation followed by my own observations of what its like to be in an earthquake.
An earthquake is caused by the fault lines that run though the surface of the earth rubbing up against each other slipping dramatically when there is too much stress on the fault. For example if you get two pieces of fabric and push them together and rub the two surfaces together with some pressure they will suddenly slide past each other once a certain level of stress between them has been reached.
This stress can be built up by any number of things glaciers for example can causes seismic stresses, however the most common one is just the gradual movement of the tectonic plates, this movement is extremely small. However due to the mass of the plates and the size of them when the stress is too great and there is a failure of the fault then all the energy has to go somewhere, some of it into heat and sound but most of it is released in a kinetic or physical form this being a the shock wave we know as an earthquake this wave is not unlike the wave in a swimming pool its energy moving in a physical medium.
Now as I said before I would write about my own experiences of earthquakes. I have my reasons for this mostly because having had experienced a few I can safely say that they are nothing like I would have imagined or even like what movies show them to be like well at least some aspects of them.
First of all I have to say when an earthquake hits I can say that everything you have learned about what to do in a earthquake either packs its bags and goes a on a quick dash out the window or it takes over and you just react the former leaving you either stunned to a standstill or just ambivalent of the disaster happening around you.
I can certainly say that my first earthquake was a rude awakening leading me to wake up and think 'I think this is an earthquake ok doorway it is then' and then fail miserably to got to my door I made it to the wardrobe and introduced my self to it with my head then made it to the doorway.
first thoughts on what that was like are to be honest if you think earthquakes are quiet you are so so wrong imagine a small train crashing into a pot factory then you have got an idea of how loud a earthquake. then there is the shaking now this isn't like a vibration kind of shaking its like your standing on a raft that someone is then pulling back and forth underneath you rather violently.
Now the unfortunate thing is that the more of these events you go through the less you react to them. I was at work having a drink upstairs in the staff room and there was a 5. something I don't for the life of me remember the exact size and in all honesty my only concern was that I didn't want to spill my drink (I didn't). please note this is not the correct reaction the correct reaction is to get under a desk or something sturdy or next to something bigger than you that can protect you (not a wall) now if you are in a supermarket when one happens DO NOT run to the end of an isle stand in the center of the isle and avoid the parts of the isle with glass items on the shelves moments after an earthquake the ground will be slippery this is why running is a bad idea. If you are in bed lie next to your bed or get under a desk. No matter what move as little as possible. walking or running is very difficult when the ground is shaking.
Now I shan't bore you further with my accounts of earthquakes unless you specifically ask me to write more about them then comment. In fact if you want me to write about something then comment and suggest it and I will try get on to it.
