Tides and Earthquakes

[ysabetwordsmith]

Another thing I didn't realize that humans didn't know: the gravitational pull of moon and sun influence earthquakes quite a bit.  You have a giant ball of mostly-molten rock with a comparatively thin crust, a slightly smaller ball of probably-solid rock and a humongous sphere of flaming gas yanking on it.  How would you NOT connect these with the crust sometimes wobbling?  I can't remember how many SF stories I've read about tidal earthquakes, and especially, the uses of tidal energy on a planet for making it hot when a star isn't close enough and/or for powering earth-engines.  And let's not forget reams of folklore about high-tide earthquakes.  0_o

Comments

[siliconshaman.livejournal.com]

Oh we knew, as you say there's tons of evidence and it's kind of a no-brainer... what science didn't know for sure was that the tides had measurable effect upon that particular fault.

See, not all fault lines are the same, some are unaffected by the tides because they're not aliened with the tides vector or the force required to make them slip is less than that applied.

What's interesting [in a OMG!] sort of way is that it means the San Andreas fault line is good deal more fragile than previously thought. Which is both good and bad... bad in that it means it requires less of a kick to get it to slip, thus more earthquakes. But good in that it lowers the chances of a Big One ever happening, and lowers how big the big one could be.