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Re: [Phys-l] Earthquake near Sendai



Richter arbitrarily chose a magnitude 0 event to be an earthquake that would show a maximum combined horizontal displacement of 1 µm (0.00004 in) on a seismograph recorded using a Wood-Anderson torsion seismometer 100 km (62 mi) from the earthquake epicenter. As a log energy scale, it scales with 3/2 power of displacement per unit. This apparently leads to a step multiplier of 31.4, though I have seen a X60 multiplier and a X10 multiplier used in print definitions... At any rate, Richter is giving way to a more closely defined scale of late. (Magnitude Moment, is it?)

Brian W


On 3/11/2011 12:43 PM, Bob Sciamanda wrote:
How does one calibrate a seismometer in Richters?
Where does one get a standard “One Richter” earthquake? :~)