A Study of the Vertical Component of Ocean Floor Vibrations in Two Geographical Chokepoints
Naval Postgraduate School Monterey United States
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The purpose of this thesis is to characterize typical levels of vibrational noise on the ocean floor to ascertain the vibrations effect on possible future bottom mounted sensors. The data used for this thesis was obtained from publicly available recorded information from four ocean bottom seismometers OBS. The OBSs were located in two geographical choke points the Luzon Strait and west of the Strait of Juan de Fuca. These highly trafficked choke points were considered to be a good representation of where these experimental bottom mounted sensors might be located should they be built. Unix-based seismic processing software available from the Incorporated Research Institutions for Seismology IRIS proved essential to obtaining calibrated data, and the methodology used to get the calibrated data is discussed in detail. The results showed that one OBS out of the four was highly variable, with decibel levels varying widely from day to day. The other OBSs remained fairly consistent. In addition, there were no common discrete frequencies between sensors that were in the same geographic area. Recommended future research involves the study of environmental effects on the OBSs, additional research to correlate the results observed in the Luzon Strait, and a look into the electronic noise floors of the OBSs used.
- Seismic Detection and Detectors
- Physical and Dynamic Oceanography