In the study of natural disasters—be they tornadoes, hurricanes, snowpacolyses, or Florida on a weekday—the event’s magnitude is just as vital to our understanding as its duration and frequency.

We know an earthquake is severe when it has a high magnitude number. The 1985 quake that devastated Mexico City was an 8. The quake that shook central Mexico this week was a 7.1. But what exactly is ...

Earthquakes are measured on the Richter scale. It was named after Charles Richter, who in 1935 developed a mathematical scale of measuring the relative size of quakes. On the Richter scale, magnitude ...

What is the "Richter scale," and what do its numbers mean? -- R.M.B., Tulsa. Although still part of our vernacular, the Richter magnitude scale is no longer specifically used to rate earthquakes. The ...

The Richter scale is perhaps the most famous of earthquake magnitude scales. But it was only intended for limited use, according to the United States Geological Service (USGS). Created by Charles ...

An earthquake rattled much of the Northeast on Friday morning, with shaking felt across the New York City metropolitan area and in communities from Baltimore and Philadelphia up through New England.

The earthquake that rattled Californians on Friday night measured a 7.1 magnitude, which doesn’t sound much worse than the 6.4-magnitude quake that struck a day earlier. But it was. The small ...

Scientists measure both the energy released in an earthquake and its damage. In 1902, Italian scientist Giuseppe Mercalli introduced a scale that measures the intensity of an earthquake based on its ...

There are a number of ways to measure the magnitude of an earthquake. Most scales are based on the amplitude of seismic waves recorded on seismometers. These scales account for the distance between ...