Tidal triggering of micro earthquakes on the Juan de Fuca Ridge

Tidal stresses beneath the oceans can be up to an order of magnitude higher than those found in the continents because of the effects of loading by oc ean tides. I have analyzed 1899 microearthquakes recorded during a 55-day e xperiment on the Endeavour segment of the Juan de Fuca Ridge for tidal trig gering. The tidal phase of the full data set and of a declustered. subset c omprising 987 events appears non-random to a high level of confidence. Eart hquakes occur more frequently near low tides, especially the lowest spring tides, when the extensional stresses are a maximum in all directions.