Earthquakes are usually caused by the movement of which geological structures?

We live a bit south of San Francisco. Here in California earthquakes are normal part of life. We have the St. Andreas Fault all along, but locally for us the smaller Hayward Fault has stronger shakes. We have an app that can warn us about the earthquakes.

I took a disasters course.

Sorry so many comments but I have to wonder when & where there was a 9.5!!

ang, It's better not to wonder lol

It's just too much writing just to fix the words dangerous "world"!

I rent and my landlady is a good friend who was going to have a storm/ tornado shelter put in my yard for me but turns out that I'm sitting on too much rock for them to dig & would have to blast the rock with dynamite 1st! I'm in a mobile home & a sitting duck! Of course I wouldn't want to be underground during an earthquake! Dangerous wield!

TWeezyA, WOW, prayers for you! And I don't care what anyone says, the weather is getting more & more fierce! There are a lot of tornados & tornado watches/ warnings where I live in Tennessee. Been that way all my life but they are causing much more damage than they did 50 years ago when I was a child here! I'm scared every time there's a thunderstorm

Arabella, Wow, prayers for you!

ang, no way not me! I felt the Whittier quake back in 1987! We lived in Montebello at that time off Whittier Blvd as The fault was on Whittier Blvd & were literally yards from the Blvd! It felt like a wrecking ball slammed into the house several times not just once! Then, after that 30-40 seconds, it hit us even harder & felt like we were picked up & shaken violently like the house was inside a snow globe for “another 95 seconds!” And that registered 6.2-6.4 on the Richter scale! So I don’t want to know how a 7 feels like cuz it’s gonna feel times ten times worse every point it goes up!! I heard that from “our awesome Seismologist” Dr Lucy Jones!! She said that; “a 5 will be is 10x worse that a 4, a 6 is 10x worse than 5 & so on!! So nope don’t want to know! And every time we have another quake, for the first 10-15 seconds I always, ALWAYS worry & think, OMG, is this the Big One?!!! I actually have the same recurring nightmare about it too!!! Thankfully we don’t have too many, that causes me to worry if it is “the big one” that causes me to be worried around this every minute of every day!!!

Earthquakes are quite Scary. we had a 5.8 Two Years ago, I Wonder what a 7 Pointer Would be like. even more Scary I don't even want to Picture It.