Peak ground acceleration design basis earthquake ground motion (DBEGM) is often defined in terms of PGA. Unlike the Richter and moment magnitude scales, it is not a measure of the total energy (magnitude, or size) of an earthquake, but rather of how hard the earth shakes at a given geographic point. The Mercalli intensity scale uses personal reports and observations to measure earthquake intensity but PGA is measured by instruments, such as accelerographs. It can be correlated to macroseismic intensities on the Mercalli scale but these correlations are associated with large uncertainty. See also seismic scale. The peak horizontal acceleration (PHA) is the
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