SACRAMENTO, Calif. — A cluster of earthquakes struck near the center of Lake Tahoe, Friday morning, the largest of which was recorded as a 4.2 magnitude.
The quakes, five in all, were recorded around 8:30 a.m. near Dollar Point. People as far away as Reno reported on the U.S. Geological Survey website, they felt the temblor but nearly all indicated the shaking was “weak.”
As Californians are getting ready to head out of town for their Memorial Day vacation plans – many to the Lake Tahoe area – some may be wondering if they have anything to be worried about.
ABC10 spoke with United States Geological Survey Scientist Dr. Robert de Groot for answers about the Tahoe cluster. Here is what he had to say:
ABC10: What can you tell us about the cluster of earthquakes in the Tahoe area?
de Groot: The cluster of earthquakes we saw this morning, one of which was a magnitude 4.2 near Dollar Point in the middle of Lake Tahoe, these earthquakes are all basically business as usual. The events that we see happening normally.
We have 50 quakes a day in California and some of them are bigger than others. Many of them, most of them, are very small. Every once in a while, we get one that’s bigger than the others. But this is basically run-of-the-mill activity in the region.
ABC10: Do Memorial Day visitors to Lake Tahoe have anything to be worried about?
de Groot: Memorial Day visitors to Tahoe should know if they feel shaking from an earthquake, they should take proper productive action – drop, cover, and hold on. We need to be ready for earthquakes no matter what. So, it’s a matter of knowing what to do.
No matter where you might be there might be an earthquake. I live in Southern California. I’m always prepared for an event. So, people should just know what to do if shaking begins.
The great thing about living in California is that there is the Shake Alert early-warning system which is active in the state. So, if people have downloaded apps to their phone like My Shake or Quake Alert USA, or they have an Android phone where they can get alerts from Google, or if they turn on their wireless emergency alerts like Amber Alerts, then they can potentially get a warning on their phone in the form of an alert.
ABC10: Do you know on what fault line these earthquakes occurred?
de Groot: It’s hard to tell [on what fault line the quakes occurred] for a couple of reasons. That particular region where the earthquakes occurred has a lot of faults. It’s very complex.
And also, the size of the earthquake, it’s very small compared to many that we have. So, it’s very difficult to determine which fault it is. And even though it was a 4.2 [magnitude], that’s still a very small earthquake. And so, it will still take some time to determine where that earthquake occurred.
The one thing we do know, which was great for us, is that we know the earthquake early-warning system Shake Alert was activated during this event. And so, we knew the system worked during this particular event.
ABC10: Is there anything out of the ordinary regarding the clustering of the quakes?
de Groot: Clusters like this are common around faults all over the state. This is a run-of-the-mill type of event. It takes a little time to unpack some of the details, but we’ve seen these things happen.
We have earthquakes throughout the state where there is one earthquake and many smaller earthquakes that follow. It’s just a matter of looking at them over the long term to see what they’re doing.
ABC10: Do you know how big earthquakes in this region could be?
de Groot: It’s hard to tell. There’s a lot of complexity there. Certainly, the region is capable of earthquakes as high as magnitude five, certainly earthquakes big enough that could cause shaking and cause harm.
We live in earthquake country. California is full of faults. The region where Tahoe is, and certainly the greater western Nevada region, is something called the Walker Lane. That part of the world is where a lot of motion is going on between the Earth’s tectonic plates on the west coast.
There is a significant chance that there are earthquakes that could cause shaking, that could cause damage and potentially cause harm to people.
ABC10: Can clusters of quakes like today be an indicator of a larger event in the future?
de Groot: People are always trying to look for patterns to see if something is somehow an indicator of something to happen. And that’s really hard to tell. We have no way of actually predicting something bigger happening.
Basically, what we try to do is understand earthquake behavior throughout the state, but there’s nothing that tells us, based on the pattern of earthquakes we saw this morning, that something bigger may happen. It’s just a matter of being ready for that event in case it happens. And really, these smaller events should tell people that earthquakes do happen in California and they will continue to happen, and we just need to be ready for them.
They still continue to be unexpected phenomena, and so all we can do is continue to be ready for them. Or, in the case of the Shake Alert earthquake early-warning system, there is the possibility to get an alert on your phone or through some other means, letting you know that shaking from an earthquake could be coming in your direction.
ABC10: Has the USGS observed any increased earthquake activity in the area or in general in California?
de Groot: Based on what we see this is just regular run-of-the-mill seismicity around the state. You get things like this happening in the southern part of the state. You see things happening on the coast in Humboldt County. This is all the typical behavior.
Again, there are 50 earthquakes a day in California and they’re going to have to happen somewhere. And it just so happens that some of these events are happening in clusters. This is the way we see earthquakes behaving and it’s really pretty normal.
ABC10: What should Californians takeaway from the Tahoe earthquake cluster?
de Groot: It’s really important to know that, even though this was a fairly small earthquake and maybe the shaking was really only felt only very close to Lake Tahoe, anybody who felt this earthquake or anybody who heard about it this is an opportunity to learn about what you can do.
If you feel shaking from an earthquake, drop, cover, and hold on. But also, most importantly as well is to also realize that in addition to doing something when you feel shaking is that if you have Shake Alert powered alerts on your phone…there a possibility that you may get an alert before shaking arrives. And if you get that alert, take that protective action.
Read more from ABC10
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