mb:Ms Screening Revisited for Large Events

Event screening of large‐magnitude events ( M w ≳5) based on m b : M s is revisited to account for the effect of the source corner frequency relative to the fixed frequencies of the long‐period M s and short‐period m b . For large events this source effect increases the slope of m b : M s relative to the 1:1 value expected for small events. The effect is demonstrated in the large earthquake m b : M s population and in the behavior of large theoretical explosions that are consistent with the more limited explosion population. The behavior is used to create a more conservative screening criterion that ensures large explosions are not inadvertently screened out by m b : M s , while not appreciably decreasing the number of screened earthquakes. This change also makes the variance of the earthquake and explosion populations more equal, which is of utility in statistical analysis. A slight trend in the explosion population and a case study of two large U.S. underground nuclear tests provide support for adopting a more conservative approach.