Discrimination of Earthquakes, Explosions, and Mining Tremors Using the Empirical Green's Function Method,
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF EARTH ATMOSPHERIC AND PLANETARY SCIENCES
Pagination or Media Count:
Using the empirical Greens function EGF method, we have estimated source time functions for earthquakes, industrial blasts, nuclear explosions, and mining tremors covering the magnitude range 0.9 - 6.6. The results show that, for events with magnitudes less than 2.5 or greater than 4.5, the time duration of the source time function can discriminate earthquakes from explosions. For large magnitude events source duration is longer for earthquakes than explosions, but at small magnitudes explosions have longer duration. For the remaining magnitude range 2.5 to 4.5 the earthquake, explosion and mining tremor populations overlap in the source duration vs. magnitude plane. However, the source time functions themselves display features that are indicative of event type, such as source directivity, spall phases, and multiple pulses in industrial blasts and mining tremors. Therefore, we conclude that source time functions inferred by the EGF method are potentially useful for regional event discrimination under a CTBT, and we recommend that further work be done to develop effective EGF-based discriminants for events in the magnitude range 2.5 to 4.5.
- Government and Political Science
- Mining Engineering
- Seismic Detection and Detectors
- Nuclear Weapons