Friday, March 11, 2011

Understanding the Earthquake Richter Scale

The terrible earthquake and subsequent Tsunami that hit Japan is truly devastating- it is still unfolding as I write this post. We send our thoughts and prayers to all affected, and hope there is minimal loss of life.
Living in Southern California, and virtually adjacent to the San Andreas fault line, we know that its not a matter of "if", but rather "when" THE BIG ONE will come locally.

Have you ever wondered what those Richter Scale earthquake rankings really mean? I'm sure there are some scientific descriptions available, but I found some easy to understand information, believe it or not, from the Scholastic Web site. Here is how Scholastic differentiates the different ranking levels:

9.0 — Causes complete devastation and large-scale loss of life.
8.0 — Very few buildings stay up. Bridges fall down. Underground pipes burst. Railroad rails bend. Large rocks move. Smaller objects are tossed into the air. Some objects are swallowed up by the earth.
7.0 — It is hard to keep your balance. The ground cracks. Roads shake. Weak buildings fall down. Other buildings are badly damaged.
6.0 — Pictures can fall off walls. Furniture moves. In some buildings, walls may crack.
5.0 — If you are in a car, it may rock. Glasses and dishes may rattle. Windows may break. 
4.0 - Buildings shake a little. It feels like a truck is passing by your house.
3.0 - You may notice this quake, if you are sitting still, or upstairs when the quake hits. A hanging object in the house might swing.
2.0 - Trees sway, small ponds ripple, doors swing slowly. You can't tell an earthquake is to blame.
1.0 - Earthquakes this small aren't felt, they usually happen below ground level.
I read somewhere that the Richter scale grows by powers of 10. If it increases by 1 point, that means the strength of a quake is 10 times stronger than the prior level. 

For example:
If an earthquake registers 2.0 on the Richter scale, it would  be 10 times stronger than an earthquake registering 1.0. A quake registering 3.0 is 10 X 10 or 100 times stronger than a quake registering 1.0  A 4.0 is 10 X 10 X 10 or 1,000 times greater than 1.0, so it is really something when thy get that high on the scale. Let's hope and pray we never see one that high.

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