This grant will fund urgently needed support through the SGER program to cover analysis and interpretation of the 1988 and 1990 sequences of earthquakes in the Upland, California, area. The second sequence was very rich in aftershocks and almost large enough to trigger a TIP (time of increased probability) in the Keilis-Borok earthquake prediction algorithm. Because the Los Angeles basin is in an episode of enhanced earthquake activity since March 1986 as comparaed to the time period 1952-1985, it is important to analyze these sequences in a timely manner. Because both small and large earthquakes are more likely during times of increased earthquake activity, this research has some urgency interms of mitigating earthquake hazards in the urban areas of Los Angeles and San Bernardino Counties. This work has direct application to the National Earthquake Hazard Reduction Program.
