Re: why did the 1994 kobe earthquake have more destruction than the northridge

Hello Janet,
There are a number of different reasons why the Japanese earthquake was more distructive than the Northridge, California quake.

Probably the most important reason was the difference in magnitudes (sizes)of the two quakes. Earthquake magnitude is recorded as a simple number on a measurement 'tool' called the Richter Scale.

The Northridge quake measured 6.7 on the Richter Scale. The "Kobe" quake measured 7.2. That doesn't seem like very much difference, does it?? However, because the Richter Scale is 'Logarithmic', it means that the Kobe quake generated more that 6 times the destructive energy of the Northridge quake! You can imagine how that alone would cause so much more damage.

The link below explains how the Richter Scale works. It gets pretty complicated and technical, but look at the table that describes the destructive power of all different values of the Scale.

http://www.seismo.unr.edu/ftp/pub/louie/class/100/magnitude.html

Another big factor in the difference of the destruction of the two quakes is the nature of the buildings that were present. Most of the modern buildings in the area of the Kobe quake survived fairly well, because they were designed to resist earthquakes. Unfortunately, the area had many old wooden structures that fell apart in the quake. Many fires were ignited after the quake and added to the loss of life.

Most of the buildings in the Northridge quake were much more modern, and built to earthquake resisting standards. There were very few fires after this quake. Because of this, there was very little loss of life in this quake, compared to the one in Japan.

As a personal note, I lived just a few miles from Northridge at the time of the quake. Many items inside my house were destroyed, but my family and the house itself were OK.

I hope that this helps!

Jay Shapiro