Paul S. Cilwa

Is The Number of Earthquakes Increasing?

I've been monitoring the USGS earthquake site for several years, now—just a hobby. Recently I downloaded a list of all earthquakes above magnitude 3, that have occurred since 1973. What I found shook me up a bit (pun intended: we may as well laugh about it!).

Here's a chart that shows how the sheer number of earthquakes has increased dramatically, starting in 1992:

This is not an artifact of "improved seismographs". Our ability to detect earthquakes has not improved since the fifties; the equipment is smaller, but not more sensitive.

This next chart shows from where the increase in earthquake numbers has come: mostly from magnitude 4.

Here's a graphic showing where all these 'quakes occurred:

I'm not prepared to say what's happening...but it is clear that something is. However, it may have reached its peak in 1996. This does bear continued observation, however. Check here for updates as they come available, and at the USGS site for the latest earthquake information.