In cases where there is no natural ordering of the traces, such as the global arrays of seismometers used to study earthquakes, the arrangement of the traces is arbitrary, and comparing neighboring traces does not have much meaning. For these earthquake seismographs, a given trace could be compared to all the other traces in the array. Naturally, the prediction filters will be longer in this case than for the examples shown here because larger delays are expected between events, but the same basic algorithm would be used. Although many more comparisons would be made within this array than would be required in a typical exploration seismic gather, the earthquake seismograph array would generally have to be processed only once, while many gathers must be processed in a typical line gathered for exploration seismology.