El Nino - the dam busts
For recorded history, we've had a benign pattern. That strong equatorial Pacific current goes slamming into the islands (Philippines, and such), jamming up warm water. Then the Sun bakes this stagnant mass, and it becomes super hot. After 7 years, it's had enough, and something triggers a water earthquake, perhaps we could call it a waterquake, but that's sounds like something else.
The El Nino is magnificent. It rolls to the East like a freight train of warm water. It hits the smooth wall of South America, and spreads North and South, like Manna from Heaven. It brings water to the deserts of Chile, and soaks California. It also does weird things to the rest of us.
California can live with this cycle, because it starts a bit early, and lingers with La Nina. That's enough to totally soak the mountains and fill the reservoirs, and they can wait for the next one. Like I said, the last one didn't happen. A slight shift in the equatorial current means this cycle is disrupted.
Earthquakes ride on the other energy, heat from radioactive decay in the deep mantle. We wouldn't be here without that, so we have to live with it. The two subjects are somewhat related since the early settlers clung around springs created by faults. It's only later that California became dependent on a benign El Nino cycle.
Update: This animation shows what El Nino does.