The area near Seattle and Vancouver Island has been found to have mysterious earth tremors, that are not earthquakes. The tremors are mild, and appear to be intensified at high tide. This seems to indicate that the gravitational pull of the moon, which creates the high tide, also can influence these geological tremors.

Researchers have long tried to prove a link between the state of the tide / moon and the likelihood of earthquakes, but without success.

National Geographic: Mysterious Tremors’ Strength Ebbs With Tides

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We do a beautiful San Juan Islands tour near Seattle every year, but haven’t felt any tremors yet! I’m always watching for related items of interest, and post them in the San Juan Islands category.