As more seismograph stations were installed around the world, it became apparent that the method developed by Richter was strictly valid only for certain frequency and distance ranges.

• 随着在全世界范围内越来越多的地震检测站的设立，这个由里查德提出的方法显示出了一定的局限性：它仅对特定频率和距离范围内的地震起作用。