Chile, Haiti: The difference between 7.0 and 8.8, between 200 and 200,000

This post contributed by John Mutter, Professor of Earth and Environmental Sciences/Professor of International and Public Affairs and Director of PhD in Sustainable Development, Columbia University, NY, along with Belinda Archibong and Danni Pi, economics students at Columbia College.

Let’s imagine it is January 10th and I tell you that my seismologist colleagues and I have just found how to predict earthquakes. I can forecast that there will be two large earthquakes quite close in time, one of magnitude 7.0 in Haiti on January 12th and one of magnitude 8.8 in Chile on February 27th.

The well-known Richter scale measures amplitude of ground motion, not energy release; when comparing energy release, a magnitude 8.8 earthquake is about 500 times greater than a magnitude 7.0 earthquake, so those two are very distinct physical events.

But even though I can tell the time, location and magnitude of future earthquakes, even though I can rank them by their respective sizes, I don’t know how many people will die, or the financial losses, or any social outcomes. The difficulty to predict the consequences on the population constitutes an immense limitation to this imaginary forecasting.

How many people would have predicted that although the energy release was 500 times greater in Chile the loss of life would be a thousand times greater in Haiti –casualties were more than 200 in Chile, and in excess of 200,000 in Haiti. Also, how many would have suggested that looting would be so much greater a problem in Chile? (more…)