What Is a Earthquake Recurrence Interval

The recurrence interval, or return period, is the average time span between earthquake occurrences on a fault or in a source zone.

What are recurrence intervals?

The recurrence interval (sometimes called the return period) is based on the probability that the given event will be equalled or exceeded in any given year. For example, there is a 1 in 50 chance that 6.60 inches of rain will fall in Mecklenburg County in a 24-hour period during any given year.

What is a recurrence interval How is it used in earthquake prediction?

When geologic events are random or quasi-random, it is helpful to represent their frequency as an average time between past events, a “recurrence interval” also known as a “return time.” For instance, there have been 7 subduction zone earthquakes in the Pacific Northwest in the past 3500 years, giving a recurrence …