![]() ![]() ![]() Each number on the magnitude scale indicated an earthquake 10 times stronger than the last-which means the quake strength between each increment of one on the scale grows as the numbers climb. Richter's idea was to track the amount of energy released by a quake the way an astronomer would measure the brightness of a star. The Richter Magnitude Scale is the method of earthquake measurement widely used in the United States last century. "My amateur interest in astronomy brought out the term 'magnitude,' which is used for the brightness of a star," said Charles Richter-the scientist behind the well-known scale of the same name-in a 1980 interview. The answer, it turns out, begins in outer space. So why do geologists talk about earthquakes this way? Why not use a scale that operates more like the ones used to measure weight, or length, or temperature, or any number of other natural phenomena? And a 7.0 releases 31.622 times as much energy as a 6.0. But no! In reality, a 6.0 quake releases 31,622.776 times as much energy as a 3.0 quake. This is what a casual observer of earthquake magnitude scales would expect: that an earthquake of 6.0 packs twice the punch of a 3.0. On a linear scale, we know that four is twice as big as two and eight twice as big as four. Here's how Jesse Singal explained it over at New York magazine earlier this year: None of this jibes with the linear way people use numbers for most measurements in daily life. Which means a 6.1 magnitude quake like the one that shook Northern California over the weekend is about twice as big as the 5.8 earthquake that rattled Washington, D.C., in 2011-and nearly three times as strong in terms of the amount of energy it released. Some more context: The 7.0 earthquake that devastated Haiti in 2010 was eight times bigger than the Northern California quake, and released 22 times more energy. But that number is based on a logarithmic scale, and can be hard to grasp.Įarthquakes aren't measured linearly, but in orders of magnitude. Today, along with those accounts, we would also get a number: the magnitude of the earthquake. These details help convey the staggering scale and reach of what was a remarkable geologic event. Two hundred years ago, Missouri was rocked by an earthquake so severe it made the Mississippi River flow backward and set off church bells in Boston more than 1,000 miles away. ![]()
0 Comments
Leave a Reply. |