Are earthquakes getting worse?
Ever since a devastating earthquake struck Haiti on January 12 followed by others in Chile, Baja California and Indonesia, many people have asked the question, “Are earthquakes getting worse?” The answer is a firm and unequivocal “No.”
I know it’s hard to believe given the devastation these earthquakes have caused and the intense level of media attention they have received. However, it turns out that large earthquake frequency has not changed at all over the last 20 years.
But don’t take my word for it. Go to the United States Geological Survey website and see for yourself. As of April 25, 2010 is on pace to have approximately 18 earthquakes larger than a magnitude 7 on the Richter Scale.
That sure sounds like a lot, but it’s only one more than last year and very close to the 15.4 large earthquakes per year that Earth has averaged over the last 20 years. Of course, some years are more active than others, but that is to be expected.
In fact, in 1995 there were 20 of these large earthquakes, but nobody talks about that year as being particularly lively. The fact that several of this year’s large earthquakes occurred near populated areas only adds to the perception that the overall frequency or intensity of earthquakes has increased.
Before the earthquake in Haiti, there hadn’t been an earthquake of that size in over two months. This ebb and flow of earthquakes is completely natural. And what about volcanic eruptions? USGS records show they have also remained constant since the 1960s, with between 50 and 70 eruptions each year.
Over the last few days, another misconception began to emerge when CNN published an opinion article by author Alan Weisman titled “Is the Earth striking back?” The piece outlined a theory that, as glaciers melt due to global warming, the Earth’s crust will begin to stretch and rebound.
It goes on to imply that this stretching could cause not only earthquakes, such as in Haiti and Chile, but also volcanic eruptions. The article even suggests this process is responsible for the recent eruption of Eyjafjallajokull in Iceland with its neighbor, Katla. “threatening to detonate next.” Do these studies exist? Yes. Is this really what they say? No.
Most scientific papers do not lend themselves to sound bites or headlines.
We can leave that to self-defined skeptics who read less than journalists.