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Welcome, and thanks for listening to the USGS CoreCast.

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I'm Scott Horvath.

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Earlier this morning, there was a 7.8 earthquake that rattled the city of Chengdu in eastern

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Sichuan China.

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Joining me on my phone today,

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Dr.

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Harley Benz, he's a scientist in charge with the National

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Earthquake Information Center, with the USGS.

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Harley, thanks for taking the time out of your busy morning to speak with us today.

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Good morning, and you're welcome.

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So can you tell us a little bit about the major earthquake that occurred in China this morning?

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Yes, there was a magnitude 7.8 earthquake.

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It occurred about 90 kilometers or 55 miles west of Chengdu, China,

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a city with a population of more than 2 million people.

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The earthquake was big enough that it was felt throughout the region.

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It was felt as far away as Pakistan, Thailand, and Vietnam.

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So are earthquakes in this area of the world,

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or in the area of China,

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uncommon?

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No, no.

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This is an area that has experienced in the past damaging earthquakes.

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The most recent damaging earthquake in this area was a magnitude 6.1 earthquake in 1989,

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And there was a magnitude 7.5 earthquake in 1933 that caused more than 9,000 casualties.

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So earthquakes in this part of China are infrequent, but not unexpected.

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Okay.

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Now, do you know if this particular quake occurred on a known fault or on a known fault

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structure?

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Well, this is an area that has active seismicity.

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There's a large basin to the east of this earthquake,

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it's the Sheshwan Basin.

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And the basin is a fault-controlled basin,

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the faults are along the northwest and western

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side of the basin.

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And we think that this earthquake occurred on the Longsmanshan Fault or a tectonically

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related fault, which is a basin-bounding fault.

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Now, obviously there's a lot of information coming out of this,

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about this earthquake.

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Where can the public go to get more information on this particular quake?

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The public should go to earthquake.Usgs.Gov.

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This is the main USGS portal for

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earthquake information.

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If you go to that main page up in the upper left hand

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corner of the website, you'll see a link to the magnitude 7.8 Eastern Szechuan

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earthquake.

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When you click on that link,

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you'll go to a series of pages that have a variety

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of maps and other kinds of content on the historical seismicity,

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the geology, and information

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about what people felt in the area,

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how many people reported what they felt,

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the intensity

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that the reported but also what people can find there is information on on how

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many people were likely exposed to severe or strong shaking these can be

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found on the links to a product that the USGS produces called pager prompt

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assessment of global earthquakes for response and there you'll find a map

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showing the prediction of the ground shaking based on the stuff that we've

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done superimposed on the population of the area.

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And when you combine the two, you

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can get information on the number of people

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exposed to severe ground shaking or moderate ground shaking.

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And for this earthquake, there was large numbers

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of people that were exposed to severe shaking.

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And consequently, there's likely damage from this earthquake.

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Wow, and all that information is available on the earthquake website through these maps

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right now, right?

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That's right.

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Great.

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Excellent.

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Well, is there anything else that you would like to add that I didn't already ask you?

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Yeah.

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For this earthquake, because of its size,

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we should expect to see lots of aftershocks.

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Often the media will ask us,

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or the public will say, well,

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how long will we feel earthquakes

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and how big will they be?

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Right.

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In the first few hours following the magnitude 7.8,

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we've recorded more than 13 earthquakes,

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the largest being a magnitude 6.

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The earthquakes are being located along a northeast trending fault,

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and they extend over

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a region about 100 kilometers or 60 miles,

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which is consistent with the size of this

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earthquake.

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In terms of the total number of aftershocks,

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aftershocks from an earthquake typically of

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this size will be occurring weeks and months from now,

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but typically with time, the number

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of earthquakes will go down and the size of the earthquakes will go down,

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but there are

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chances of having other large damaging earthquakes as part of this sequence occurring in the

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next few days and weeks there is a potential for that.

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Well great Harley

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thank you very much for providing us with all that great information and

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thanks for joining us this morning on the phone.

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You're welcome.

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And that does it

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for this episode of the USGS CoreCast.

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Thanks for listening and don't forget to

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visit our website at usgs.Gov slash CoreCast where you can find more

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information links and transcription for this episode and other episodes in the

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And just as a reminder, the USGS corecast is a product of the U.S.

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Geological Survey, Department of the Interior.

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Until next time, I'm Scott Horvath saying, keep it cool.