Abstract
Monthly measures of general unidentified flying-object reports (UFORs) and a specific subsample of luminosity-type reports (LRs) were compared with monthly variations in several seismic indices within Washington state for the years 1970 to 1976. A strong correlation occurred between the magnitude of a measure of the total energy released in a month and the time since the previous peak in UFORs and LRs. Percentage changes in UFORs and LRs with respect to the previous month were not correlated significantly with the occurrence of larger magnitude (M ≥ 2.0) quakes but were moderately to strongly correlated with the numbers and percentage changes from the previous month in events of smaller magnitude (1.0 ≤ M < 2.0). These seismic events also showed a systematic variation in lag time with the larger displays of seismic energy. Peaks in both UFORs and small magnitude events occurred between 0 to 6 mo. before increments with the larger seismic energy values; the average lag was about 2 months for both phenomena. Maximum correlations between numbers of UFORs and LRs and the numbers of events of smaller magnitude occurred when increments used in analysis averaged about 3 months. These analyses indicate that systematic and intricate relationships between samples of UFORs and earthquake measures are evident when the latter reflect a more representative sample of seismic events within the test area.