Chile Earthquake 2010 | The Conservation Report

Chile’s 8.8-magnitude earthquake—which resulted in scores of aftershocks stronger than a magnitude of 5—is among the strongest earthquakes ever recorded.

The strongest earthquake ever recorded occurred in Chile on May 22, 1960, which measured 9.5 on the Richter scale. According to a scientist from the USGS’s National Earthquake Information Center, “The [most recent] Chile quake released 500 times more energy than the quake that hit Haiti.”

Earthquakes are measured on the Richter Scale, which illustrates the amount of energy released during an earthquake:

Most people have heard of the Richter Scale for measuring the ‘size’ or ‘strength’ of an earthquake. This scale is quantitative and based on the amount of energy released by an earthquake.

The inferred energy of a quake is a function of both the amplitude and the duration of a single wave. The seismogram below shows waves with a wide range of amplitude (up to +/- 350) and duration (the first big wave cycle – up, down, back to zero – started just after 8 minutes on the chart and ended nearly 40 seconds later; other waves lasted only seconds).

So when you do all the math, here is what you get.

One unit on the Richter Magnitude Scale corresponds to a tenfold increase or decrease in the amplitude of the wave on the seismogram – 350 in this example would become either 3500 or 35! This change, when summed over all the wavelengths and wave types, translates to a 30 times increase in energy.

So a seismograph (the instrument) that recorded a 1 cm deflection on a seismogram (the tracing) for a magnitude 5 earthquake would show a 100 cm deflection for a magnitude 7 quake that released 30×30 = 900 times as much energy. You do the math for a magnitude 8 quake!

However, the strongest earthquakes aren’t necessarily the deadliest. From Voice of America:

Throughout history, the most powerful earthquakes have not necessarily been the deadliest. The deadliest earthquake of modern times was recorded in 1556 in central China. More than 830,000 people were reported killed in that quake, which had an estimated magnitude of 8.

More information on the massive Chile earthquake is available from the National Earthquake Information Center, and tsunami warnings are available via NOAA’s National Weather Service. To learn about supporting disaster relief in Chile go here. Images from the Chile earthquake can be found at a real-time image search via Twitcaps. The U.S. Department of State has a Chile Task Force, which may be contacted via email at ChileEarthquake@state.gov or by calling 1-888-407-4747. Google has a set up a person finder for the Chile Earthquake at http://chilepersonfinder.appspot.com/.