A magnitude 7.0 earthquake off the coast of California prompted worry on Dec. 5, but now that it's passed, could the coming days bring more strong quakes? Let's talk to a seismologist to find out.
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00:00Seismology is a little different from meteorology, so we want to get a little bit more information
00:05on this here. With today's earthquakes, we want to bring in Maureen Long, and Maureen is a
00:08seismologist and professor and chair of Earth and Planetary Sciences at Yale University. Maureen,
00:14thank you so much for making time for us. I know this is a very busy afternoon for you.
00:19That's right. Seismologists have been in demand today.
00:22Absolutely, absolutely. Well, Maureen, what surprised you, if anything, about today's
00:26earthquake? And every weather event or seismology event has some unique characteristics. Is there
00:31anything that makes this earthquake unique? Yeah. Anytime you hear about a magnitude 7
00:38earthquake, that's always a big deal. And so certainly magnitude 7, that's a large event.
00:44This one happened offshore of California and in an area where we expect and do see a lot
00:51of seismicity. So in that sense, this earthquake today was not unexpected. This is an area that's
00:57actually at the junction of three different tectonic plates. There are lots of earthquakes
01:02there. So in that sense, this wasn't a unique event. But anytime you have a magnitude 7,
01:07that's going to make seismologists and everyone else sit up and take a look. And we understand
01:12that there have been a number of aftershocks today. Are you able to determine if they will
01:16continue and for how long? Yes, that's right. As you said, there have already been a couple dozen
01:22aftershocks that have been measured. The USGS, the US Geological Survey, has released an aftershock
01:28forecast, as they typically do after large events. So they're saying that there's about, at this
01:34point, about a 30 percent chance or so of a magnitude 5 or greater aftershock in the next
01:40week or so. But we very much expect that aftershocks will continue. And most of them are
01:48small. Many of the aftershocks today were magnitude 3, 4 or so. But we expect that aftershock
01:54sequence to continue for days, weeks, maybe even months for an earthquake of this size.
02:01And even separate from an aftershock, is one more significant earthquake sometimes a harbinger
02:07of additional significant earthquakes? Or is there really not a much of a correlation? Are
02:13quakes like these just a single isolated event typically? Yeah, that's a terrific question. And
02:19the scientific answer to that is a little bit nuanced. In a small percentage of cases after
02:25an earthquake like this, we might expect to see a larger earthquake. Now that only happens, again,
02:30it's a small percentage of cases, maybe a few percent of the time. So the most likely scenario
02:36here is that aftershocks that, you know, events that we'll see in the days, weeks and months to
02:41come will be smaller. Having said that, we know that this is an area that is very tectonically
02:47active and we will see earthquakes in the future. That's a certainty. So certainly for folks who
02:55live in the affected area, you know, knowing that this is a place that gets earthquakes and knowing
03:02how to be prepared and what to do is important going forward. And that's true no matter what.
03:07All right. Well, we certainly appreciate all of your insight there. Maureen Long
03:11from Yale University. Maureen is a professor of Earth and Planetary Sciences. Again, thanks again,
03:16Maureen. Really good insight. We appreciate all that. My pleasure. Great to be with you. Likewise.