How Do Scientists Tell the Difference Between Natural Earthquakes and Earthquakes Caused by Nuclear Tests?

SCIENCE

North Korea just announced a successful underground test of a nuclear device, and seismic evidence supports that claim. How do scientists know the earthquake in North Korea was triggered by an underground nuclear blast and was not a naturally occurring tectonic event? (BBC)

Why are North Korea’s nuclear tests such a big deal, anyway? Use our great study guide to find out.

Teachers, scroll down for a quick list of key resources in our Teaches Toolkit.

This lovely infographic introduces a great article about how scientists study different seismological events. Infographic by Lawrence Livermore National Laboratory Science & Technology Review (March 2009)

This lovely infographic introduces a great article about how scientists study different seismological events.
Infographic by Lawrence Livermore National Laboratory Science & Technology Review (March 2009)

Discussion Ideas

Map and poster courtesy the good folks at the USGS

Map and poster courtesy the good folks at the USGS

 

  • How does underground testing trigger quakes big enough to be detected on the other side of the world?
    • Well, first of all, seismographs are incredibly sensitive these days and it doesn’t take much to set one off.
    • According to the good folks at UC Berkeley Seismological Laboratory, underground nuclear explosions cause “very strong forces [to] rapidly act inside the Earth. This leads to intensive shaking of the rocks around the hypocenter, which in turn generates elastic waves. [More on those below.] They can travel thousands of miles and are detected by sensitive seismometers.”

 

 

  • Can anything besides a nuclear explosion trigger activity on a seismograph?
    • Yes!! Lawrence Livermore describes “Earth’s never-ending seismic activity” as including meteor impacts, volcanoes, and even ocean waves crashing on shore. What other natural phenomena might cause the earth to shake?
    • Other man-made earthquakes include mine collapses (detailed in the Lawrence Livermore graphic up-top) and fracking activity. What other man-made activities might cause the earth to shake?

 

TEACHERS TOOLKIT

BBC: North Korea claims success in fifth nuclear test (article)

USGS: M5.3 Explosion – 19km ENE of Sungjibaegam, North Korea (poster and maps)

Nat Geo: Did North Korea Just Detonate a Hydrogen Bomb? (study guide)

University of California at Berkeley Seismological Laboratory: Of Nuclear Bombs and Earthquakes (short article)

Lawrence Livermore National Laboratory: Sleuthing Seismic Signals (infographic and article)

3 responses to “How Do Scientists Tell the Difference Between Natural Earthquakes and Earthquakes Caused by Nuclear Tests?

  1. Pingback: Bombs Away on YouTube | Nat Geo Education Blog·

  2. Pingback: 11 Things We Learned This Week! | Nat Geo Education Blog·

  3. When our Earth-Mother is hammered by inordinant amounts of bombs on her surface, not all enegry is dissapated above the surface. The balance is absorbed underground and will naturally follow any fault lines, travel through them until they reach a no-through area. Possibly creating an undeground earthquake at the deepest depths of the ocean. The small measurable shift will manifest as a tsunami wave at the surface. Maybe consider Ache’, Indonesia. It is at the fault line that begins over Iraq. Just coincidental or all ow simple reason to guide and direct our research and intelligence

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