Question: Quakes over the last week

http://neic.usgs.gov/neis/bulletin/

I know very little of geological science. The question is should we have some concern over the # and scale of these quakes. Is this unusual or is it simply the day to day rumblings of our planet? Quite frankly, seeing all of these with 4,5, and 6 next to them is a bit unsettling but I'm not very knowledgable of the science behind it. Seems that the Sci/Tech forum was a good place to throw it out for feedback.

 

.

 

On the grand scale of things, these recent quakes are pretty normal. This one in the Indan ocean is not even the biggest of the last hundred years.


They happen. Nothing to get excited about.

- azimuth

 

Along with being an aging freak, I am an earth scientist, so I thought I might put in a comment here.


Earthquakes are classified by the amount of energy they release on what is called the modified Richter Scale. Each increase of a whloe number value, i.e. 8.0 to 9.0, represents an increase of 30X the magnitude over the lower number.

The largest quake since we have been measuring them occurred in 1960 on the coast of Chile. It was measured at 9.5. It generated tsunami that hit British Columbia, Hilo, HI and Japan with casualties.

The second largest was the so called "Good Friday Quake" in 1964, that was centered below Prince William Sound, Alaska. It was measured from 9.2 to 9.4 by various sources.

These are all part of a normal and regular process whereby large rigid portions of the Earth's crust, called plates move around on the surface of the planet. In placeswhere there are boundaries between the plates, seismically active areas exist, along with what are called volcanic arcs.

What we perceive as disasters are just part of the way the planet works. It has gone on for over 4 1/2 billion years, much longer than our history here and will continue with, or without out existance for the life of the Earth. We may be able to influence short term changes to the biosphere, but the planet will never notice any disturbance due to our interference.

 

Here's a real world evalution of what I think it might be like (I live in CA, so I've felt up to a 6.5):


2: Not even noticeable

3: Barely noticeable if you're in bed or sitting still, otherwise nope

4: Noticeable, but gentle and only a little rumble

5: Noticeable, makes you wonder if you should go outside, but you stay inside.

6: A little worried, glasses and plates rattle, go outside.

7: Get outside quick.

8: Violent shaking, think you might die.

9: Crazy

 

Thanks to all of you. This has been an ongoing curiosity and worry of sorts (based on hollywood movies). It's good to know that this is actually something quite normal.