The Use of Ocean Tide Records to Detect Motions Premonitory to a Tectonic Event in the Long Beach, California Area

摘要

Marigram records of ocean tide fluctuations at three tide stations operating in the Santa Monica/Long Beach, California area at the time of the 10 March 1933 Long Beach earthquake (magnitude 6.3) were digitized onto magnetic tape. Time series of hourly instantaneous tide level observations were generated and processed under a least squares criterion to remove the effects of the nine most energetic lines of the ocean tide harmonic spectrum. The resulting residual series did not contain any anomalous premonitory motions indicated by another residual series previously analyzed at the National Center for Earthquake Research. Auto- and cross-correlations of the three residual series used revealed only two possibly significant auto-correlation peaks for two stations lagging themselves by 24 hours. (Author)