There has been increased quake activity on the west coast the last two days. Nothing above 4.1 as I see. Mag 4 tremblers are not unusual in California.
As I remember the Richter Scale is logarithmic and each integer represents a 10-fold change in energy. Checking with
wiki I see:
quote:
Magnetude
| Average Quake Effects
|
3.0—3.9
| Often felt by people, but very rarely causes damage. Shaking of indoor objects can be noticeable.
|
4.0—4.9
| Noticeable shaking of indoor objects and rattling noises. Felt by most people in the affected area. Slightly felt outside. Generally causes none to minimal damage. Moderate to significant damage very unlikely. Some objects may fall off shelves or be knocked over.
|
5.0—5.9
| Can cause damage of varying severity to poorly constructed buildings. At most, none to slight damage to all other buildings. Felt by everyone.
|
So lots of little quakes in the 3.0—3.9 are just noticeable but rarely cause damage, and even quakes in the 4.0—4.9 range rarely cause significant damage (depending on what things on shelves that fall off involve), and it is only when you get into the 5.0—5.9 range that you begin to get significant damage ... to poorly constructed structures.
This is what I was talking about it being an "alarmist" site rather than a conspiracy theory site (although it seems the author is willing to take that path), as he talks about pending quakes as posing a great danger yet most of the quakes he documents are under 4.5, and he makes it seem more dangerous than it is.
Nor should we be surprised by any links between quakes and volcanic activity as this link is very well documented along plate boundaries.
That being said, I found the global scale that he documented quite fascinating -- the earth is indeed in a rather constant state of flux and change, and if nothing else this is one way to show that fact.
I've only experienced one quake, while camping in California, and we didn't know what it was until we left in the morning and went to lunch. It was in the 3's as I recall.
Enjoy