One of the fundamental things I’m interested in with my /obits/ obsessions is what type of contributions to the world are worthy of publishing the day after you die? One type is the improvement. It’s one thing to be Charles Richter and come up with the Richter Scale.
It’s another to improve such things incrementally, less eponymously.
Keiiti Aki, 75, Is Dead; Developed a Way to Measure the Strength of an Earthquake – New York Times.
He was widely known for his concept of the “seismic moment,” which he developed in the 1960’s as a means of measuring the magnitude of earthquakes.
While studying a huge earthquake that struck Niigata, Japan, in 1964, Dr. Aki devised a calculation that considers the area affected by an earthquake, the rigidity of the underlying rock and the distance the rocks slip.
The result – the seismic moment – is a measure of the energy released by an earthquake, and is used in addition to the moment magnitude scale, now the standard measurement announced to the public after disasters like the earthquake-generated tsunamis in December.