How frequent are 6.0 and higher earthquakes?
What is the average duration of time BETWEEN such a quake, and the next one, 6.0 or greater?
There are on average about 150 earthquakes world wide that have magnitudes greater than 6.0 on an annual basis. Just using an average interval between all of them would indicate that we should experience a magnitude 6.0 or greater, somewhere on the planet, about every 2 and a half days.
On a specific fault or within a specific region, the interval between magnitude 6.0 or greater events is likely to be on the order of decades or centuries. For example, for the Parkfield segment of the San Andreas fault, there was an average interval of 22 years between magnitude 6.0 events. Based on that, they made a prediction. They were off by about 11 years I think it was.
What are the causes of the Yushu earthquake?