Peak ground acceleration (PGA) is a measure of earthquake acceleration on the ground and an important input parameter for earthquake engineering, also known as the design basis earthquake ground motion (DBEGM)
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 in a given geographic area (the intensity). The Mercalli intensity scale uses personal reports and observations to measure earthquake intensity but PGA is measured by instruments, such as accelerographs, and it generally correlates well with the Mercalli scale. See also seismic scale.
The peak horizontal acceleration (PHA) is the most commonly used type of ground acceleration in engineering applications, and is used to set building codes and design hazard risks. In an earthquake, damage to buildings and infrastructure is related more closely to ground motion, rather than the magnitude of the earthquake. For moderate earthquakes, PGA is the best determinate of damage; in severe earthquakes, damage is more often correlated with peak ground velocity.
Read more about Peak Ground Acceleration: Geophysics, Seismic Risk and Engineering, Comparison of Instrumental and Felt Intensity, PGA Hazard Risks Worldwide, Notable Earthquakes
Famous quotes containing the words peak and/or ground:
“I think I’ve been good, but I want to be better. I think women reach their peak in their mid-thirties.”
—Mary Decker Slaney (b. 1958)
“And out of the ground made the Lord God to grow every tree that is pleasant to the sight, and good for food: the tree of life also in the midst of the garden, and the tree of knowledge of good and evil. And a river went out of Eden to water the garden.”
—Bible: Hebrew Genesis 2:9-10.