2011 Tōhoku earthquake and tsunami for the event was based on a calculation that requires only about 3 minutes. This calculation is, in turn, based on the maximum amplitude of the seismic wave. The amplitude of the seismic wave is measured using the , which is similar to Richter magnitude scale. However, these scales "saturate" for earthquakes that are above a certain magnitude (magnitude 8 on the JMA scale); that is, in the case of very large earthquakes, the scales' values change little despite large differences in the earthquakes' energy. This resulted in an underestimation of the tsunami's height in initial reports. Problems in issuing
Kardashev scale Kardashev scale The Kardashev scale is a method of measuring a civilization's level of technological advancement based on the amount of energy a civilization is able to use. It was proposed by Soviet astronomer Nikolai Kardashev in 1964. The scale has three designated categories: The scale is hypothetical, and regards energy consumption on a cosmic scale. Various extensions of the scale have since been proposed, including a wider range of power levels (types 0, IV and V) and the use of metrics other than pure power. In 1964, Kardashev defined three levels of civilizations, based on the order of magnitude