Epicentral Estimation for Five Lasa Events Using Frequency-Wavenumber Spectra. Large-Array Signal and Noise Analysis.

摘要

Five short-period events were processed using a 15-sec gate for the LASA A0, D-ring subarray, a 10-sec gate for the extended E3 subarray, and a 5-sec gate for the F1 subarray. Gate positions were based on time-trace playbacks and were chosen to include the primary P-wave arrivals. For an event recorded on 21 June 1967 from eastern Russia or northeastern China, all f-k give a reasonable accurate location at the 'peak' frequency for this event; however, this is not true for all events. Three types of f-k spectra were calculated at 1.00 Hz. At this frequency none of the f-k spectra peak at the proper k, but conventional and high-resolution spectra, using all the outer ring (D-ring) subarrays as reference, did give some indication of the event. (Author)