Question

Module 10: Seismology/Earthquakes & tsunamis Magnitude/Amplitude/Energy conversions: According to the Richter scale, a series of earthquakes have a foreshock of magnitude 4.0 with an amplitude of 10 mm and an energy equivalent to 30 tons of TNT. The amplitude for a magnitude 3.0 aftershock will be millimeters. The energy for a magnitude 6.0 mainshock will be tons of TNT.

Answer 1

the - The amplitude for a magnitude 3. o after shock will be 0.001 millimeters • The scale was calibrated by defining a magni- tude 3 shock as one that Iroduces (at a distance on 100km (62 mi)) a maximum amplitude of (1 um, or 0.001 millimeters) or a seismogram recorded by a Wood- Anderson torsion seismograph, Ans. The energy for a magnitude 6.0 mainshock will I be 6 270 tons of TNT. A magnitude 4.0 earthquake is only equivalent to about - 6 tons of INT explosives, but because the Richter & cale ů a base - 10 logarithmic scale, the amount of energy released increases quickly: A magnitude 5.0 earthquake is about 200 tons & INT, magnitude 6.0 is 6,270 tons of TNT and so on.