>Giant earthquakes: not as random as thought

>https://phys.org/news/2018-01-giant-earthquakes-random-thought.html

![](https://imageshack.com/a/img924/6492/rYeg70.gif)

>Larger earthquakes recur more periodically: New insights in the megathrust earthquake cycle from lacustrine turbidite records in south-central Chile

>https://www.sciencedirect.com/science/article/pii/S0012821X17305757?via%3Dihub


A known repeat cycle of anomalistic/draconic/synodic/annual lunisolar periodic variations is 353 years. Within that span, there is a single maximal gravitational forcing that the moon and sun apply to the earth.

From Keeling Whorf

![kw](https://imageshack.com/a/img923/275/EkQMAG.png)

Example:
[The Super Blue Blood Moon Wednesday Is Something the US Hasn't Seen Since 1866](https://www.space.com/39532-super-blue-blood-moon-occurs-wednesday.html)

[Tides, and the pull of the moon and sun](http://earthsky.org/earth/tides-and-the-pull-of-the-moon-and-sun)

![](http://en.es-static.us/upl/2012/10/spring_tide.gif)