It’s one of the most enduring mysteries in earthquake science: Why do small earthquakes stay small, while others grow into monsters?
A group of researchers offered a partial, but tantalizing answer this month: The moon and big tides.
How does this work?
The scientists zeroed in on times of high tidal stress, which can occur twice a month, during the full moon and new moon. During these moments, high tides are at their highest — flooding the tallest reaches of a beach — and about six hours later, low tides are at their lowest for the month, with seawater retreating to the farthest point toward the ocean.
This produces massive...