RENEE MONTAGNE, HOST:
People in Southern California are on edge this morning bracing for aftershocks from the most powerful earthquake in two decades. It hit last night, a magnitude 7.1 quake centered near Ridgecrest about a hundred miles north of Los Angeles. That's the same location as Thursday's 6.4 magnitude quake. And there are reports of fires, injuries and power outages in the area.
Jacob Margolis is with member station KPCC. He's the host of the podcast "The Big One." And he joins us now. Good morning.
JACOB MARGOLIS, BYLINE: Thanks for having me.
MONTAGNE: Please start off by telling us about last night's quake - much, much bigger than the earlier one.
MARGOLIS: Yeah. Just to give people an idea, on Thursday, when I was running around, I didn't even notice the 6.4 down here in Los Angeles. They certainly did up in Ridgecrest. But down here in LA, you might've missed it. The 7.1 - I haven't talked to anyone who has. I was sitting around with my wife when, all the sudden, everything in the house started swaying. Pots and pans started clanging. And it just kept building and building and building. And in Southern California, especially when you have earthquakes, it's this - there's this waiting period. You're waiting to see just how bad it's going to get.
So in terms of numbers, the quake last night - what? - a 7.1, there was 11.2 times more energy released than the 6.4. That's pretty big. And since then, the aftershocks have not stopped, not that we're feeling them here in Los Angeles, or not all of them. But there have been more than 350 aftershocks above a magnitude 2.5 since the 7.1 last night. They've been pretty much nonstop.
MONTAGNE: And just to make the point, that earthquake, when you're talking about Los Angeles, it's a hundred miles south of that earthquake, for all that shaking that you're feeling. But, you know, this quake - the - is not related to what a lot of people know about earthquakes, which is the San Andreas Fault, right? That's theoretically the big one.
MARGOLIS: Yeah. Well, a big one can come from any number of faults here in Southern California. So if you looked at a map of Southern California and wanted to imagine all the faults, just throw a pile of spaghetti down on it, and all those little strands would be faults all over the place. These - this set of faults is inland from the San Andreas.
And so there was a less-than-1% chance that we would've had an above-7.0 magnitude earthquake yesterday following the 6.4 on Thursday, and that happened. As of today, there is a less-than-2% chance that we could see another magnitude 7 today, but we're going to have to see how that shakes out.
The San Andreas is not directly impacted by these faults, as far as we know. But there are a whole lot of faults in that area that might've taken a strain of some of these smaller faults that - when they released all their energy, because that strain doesn't just go away. It has to go somewhere else. And some of the other faults in the area took it on.
MONTAGNE: And how much do we know at this moment in time, this early in the day, about what the damage is up there?
MARGOLIS: You know, we saw reports. As we were doing live coverage, we saw reports of damage start to trickle in. But, really, right after an earthquake, it is, like, fog of war. No one knows what's going on. Emergency responders are just going out trying to survey the damage. We did hear reports of fires.
We got some calls into our - into KPCC of people telling us that they had fallen. One woman said that she thought maybe she broke her wrist. And there were a lot of people who were just afraid to go back into their houses, which is another big thing with big earthquakes - is that it disrupts people's lives not just for that one moment, but continuously, especially after aftershock after aftershock after aftershock keeps hitting.
MONTAGNE: All right. Well, we'll be getting updates throughout the morning. And thanks very much for joining us. KPCC's Jacob Margolis, science reporter and host of a podcast called "The Big One: Your Survival Guide." Thank you, Jacob.
MARGOLIS: Thanks. Transcript provided by NPR, Copyright NPR.