The Brawley, California Earthquake Sequence of January, 1975, and triggering by Earth tides

Publisher Website
Google Scholar
Abstract
Occurrence times of many individual events in the 1975 Brawley swarm correlate with times of theoretical gravity tide maxima and minima. Most events occur near the extrema or during declining gravity, with relatively few occurring during increases in gravity. The swarm itself began at a time when daily peak‐to‐peak gravity tide variations were increasing. Review of previous correlations and correlation attempts shows negative results for global or regional distributions of earthquakes, but successful correlations for small areas and individual swarms or aftershock sequences. The explanation proposed for this dichotomy is that the oceanic tides cause large and variable phase differences between the theoretical gravity tide (based on the positions of the sun and moon) and the actual deformational solid earth tide for locations in and near ocean basins. If it is indeed the deformational earth tide (strain) which triggers some earthquakes, then the correlation of earthquake times with theoretical gravity tides is always unsuccessful for large geographic areas because of the variable phase of oceanic tides, and is often successful for small areas because the oceanic effect is constant.

This publication has 11 references indexed in Scilit: