Signal and Noise Analysis Report, Aleutian Islands Experiment, Ocean-Bottom Seismographic Experiments
Abstract
Aleutian Islands signal and noise data were analyzed to determine the teleseismic recording capability of the Ocean-Bottom Seismograph (OBS). From this analysis it was concluded that both noise and signal levels vary with OBS location, and the lowest noise sites are in deep water far from land. The noise spectrum is sharply peaked at 1 Hz; as the frequency increases to 2 Hz, the levels are down 10 to 20 db. Thus, ocean-bottom seismographs can perceive higher-frequency events up to a full magnitude better than they can perceive 1- Hz events (important in detecting explosive events at teleseismic distances). OBS perceptibility is quite variable at 1 Hz because of the variability of signal level with location and noise level with location and time. It appears that events of magnitude 5.0 or greater can be detected by at least some of the OBS stations, provided that the events are 40 deg. or less from the array. Events of magnitude 6.0 or greater usually can be detected at all epicentral distances. The noise field determines the type of processing which can be used.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1968
- Accession Number
- AD0859704
Entities
People
- A. F. Linville
- Gary D. Mcneely
- R. F. Howard
- Terence W. Harley
Organizations
- Texas Instruments