Increase In Earth Quakes?

If you havent been under a rock you have heard about the Japan Earth Quake and Tsunami disaster. The massive earthquake measured an incredible 8.9 on the ricter scale and was centered several hundred kilometers off the east coast of Japan. To give you an idea of the power of an 8.9 earth quake, its roughly 100x more powerful than the North Ridge, California earth quake of 1994. The Japan quake was the 5th largest Earth Quake in recorded history and released as much energy as 336 million tons of TNT. Its truly an event of almost biblical proportions. The quake triggered a massive tsunami that has completely devastated cities and communities all up and down the coast, particularly in Northern Japan.

The government of Japan predicts that there will be a death toll in the thousands.

You may have noticed that there have been several major earth quakes over the last few years and especially in the last year. Since the begining of 2010 we have seen major quakes in Haiti, Chile, China, Indonesia, Mexico and most recently New Zealand. The 2010 quake in Haiti was one of the highest death tolls in history for an earth quake, with over 200 000 killed. We have also seen major volcanic eruptions in Iceland and Indonesia. I cant forget to mention the massive 9.0 indonesian quake that trigged the 2004 boxing day tsunami disaster. The boxing day tsunami killed over 220 000 people in Thailand, Indonesia, India and several other countries in the region.
The question is: Are there more earth quakes now than ten or twenty years ago? Could we be heading into some kind of era of increased seismic activity? Interestingly there were more major quakes in 2010 than any year in the last decade with roughly 26 significant quakes.
 

According to the US geological survey, there has not been any statistical increase in the total amount of ‘tremors’ in the last decade compared to the 1990s or the 1980s. Here is what is interesting though; in the 70s, 80s and 90s there were no quakes measuring more than 8.5 on the ricter scale. Since 2000 there have been at least 5 earth quakes measuring over an 8.5. Quakes measuring over 8.0 in the ricter scale are also more frequent over the past decade. Since 2000 there have been at least 14 quakes measuring over 8.0, in the 1970s, 80s and 90s there were a total of just 16.

So according to the data there seems to be a real trend of frequently stronger earth quakes. The increase is likely in part due to increased proliferation of seismic measurement equipment, as well as population growth. Its important to note that 10 years is a very small period of time for these types of events and things could very well even out over the next few decades.

I think an interesting postulation is that when a large earth quake takes place it can trigger quakes in other parts of the world. You can see examples of this when you look at the data, quakes often occur within days of one another. In one week in November of 2004 there were 3 major Earth Quakes between Japan and New Zealand.