Saturday, March 05, 2011

Aftershocks sample pack

In the last six months since September 4th (Quake#1) I have slowly become quite an expert, I feel, on the experience of earthquakes. To be specific, it's aftershocks that I've come to know intimately. Aftershocks are smaller magnitude earthquakes that happen after a larger earthquake. It really is semantics because, as we found out on December 26th (Quake#1.5) and again on February 22nd (Quake#2), an aftershock is not necessarily less damaging than its proud parent quake. In the case of Quake#2 there is however some argument amongst experts about whether it really was an aftershock of the Quake#1 or not.

I would actually faint with surprise if a consensus were reached on the 'aftershock-or-not' question because, when it comes to earthquakes, it is becoming rather alarmingly obvious that everything is a guess. Even someone with a PhD in earthquakeology, that watches a seismograph instead of TV, and sits in their backyard with a stethoscope pressed to the earth in their spare time and plots both the moon and the corona holes, and has named their child 'Geo' could not tell us when or where a quake will happen, at what depth or how strong it will be or, afterward, whether it was a new quake or an aftershock. The 'experts', whether of the hard science or 'fringe' persuasion, are good at arguing about who is right or wrong, but not really very useful when it comes to telling the general population what is going to happen or on what day to leave town. My thinking is that it's just a very inexact science and that earthquakes happen as a result of a number of interacting natural forces (or perhaps even unnatural ones, e.g. HAARP), which will probably never be sussed out because the 'perts are too busy marking their territory by pissing on each other to sit down and brainstorm.

I also have developed, all by myself, another highly exact theory based around the fact that my nieces birthday coincides with Quake#1 and my nephew was born the day before Quake#2. I predict that quakes happen on the birthdays of my nieces and nephews. Don't knock it. So far it's been very accurate. Going by my empirically proven theory, we should expect another big quake on or around July 16th. I cannot be more accurate because I'm a terrible aunty and have forgotten the exact date of my older nephews birthday.

Lately I have been discussing with other Cantabrians the various 'types' of aftershock. They are not all the same, there are flavours. Allow me to educate you. This is what's in your aftershock sample pack today:

* The 'slow-burner' - usually starts with a warning rumble (imagine a freight train in the distance) followed by slow shaking which builds to a crescendo with deafening noise (freight train running through the room) and then dies away. Quake#1 was like this, the first machinations just woke us up 'relatively' gently, then the serious shaking and noise kicked in.

* The 'gotcha' - goes from nothing to violent shaking, no warning noises, just woah to go. Quakes #1.5 and #2 were like this. I think this is a feature of quakes that are very close. 'Gotcha' quakes seem to cause more damage.

* The 'bomb' - sounds like an underground explosion, usually accompanied by some sort of jerking movement, but sometimes it is just noise and very little movement. Sometimes they sound very deep and faraway and sometimes they nearly make you soil yourself.

* The 'grind' - sounds like the earth creaking and groaning. You can almost imagine the plates of the earths crust grinding against each other. Sometimes loud, sometimes not very. Usually you get a sort of 'swaying' motion with this noise. Sometimes a 'grind' ends with a 'bomb'.

* The 'skipping bass' (or maybe, but not quite 'machine gun') - the noise is 'duh-duh-duh-duh', like someone playing a single note on the bass guitar, very quickly. It's also a bit train-like 'cha-cha-cha-cha'. The movement can be anything - side to side, up and down, usually quite jerky. The noise can start in advance of the quake or come on at the same time in a 'gotcha' fashion.

* The 'visitor' - this quake seems to move around. It can sound and feel as if it came in the bedroom window and left by the back door, rattling everything on the way but hardly moving the lounge at all.

* The 'just kidding' - loud noise, very little to no shaking. These are very disconcerting. You are bracing for a biggie, but then nothing happens.

* The 'rock you to sleep' - slow sway, maybe a soft noise. Really not traumatic, if you are used to quakes.

* The 'bounce' - bounces you straight up and down, usually with the 'skipping bass' noise.

* The 'wiggle' - small, fast side to side movements that makes all the glass tinkle but doesn't knock much over.

In the time I've been writing this post there have been three aftershocks (10.45, 10.49 and 11.00pm), all of them 'wiggles' with a common, garden variety aftershock rumble (freight train). At the moment, as I was explaining to Shauna in a rather rambling, sleep deprived email, we are having a) Quake#1 aftershocks (yes, still.. now and then), b) Quake #2 aftershocks and c) aftershocks on any aftershock that was big enough to warrant its own aftershocks. That's quite a bit of rocking and rolling. The other possibility is that the government has actually installed a subway. Right under my house. Nothing would really surprise me these days - except a night of uninterrupted sleep. How about it mother nature? You do that for me and I'll say something nice about you in my blog tomorrow. Deal?










4 comments:

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  2. Comment spam.... pfft.

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  3. HATE comment spam!

    Try to get some sleep, love. Just the right amount of wine will help...not too much though, because you know that always gives you the "wide-awakes" around 3:00am. Which sucks.

    I really hope you get a quiet few hours.

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