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USGS CMG InfoBank: Electromagnetic Earthquake Precursors?

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Comment: 19:33 - 20:58 (01:25)
Source: Annenberg/CPB Resources - Earth Revealed - 25. Living With Earth, Part I
Keywords: "Anthony Frasier-Smith", "Loma Prieta Earthquake", "low frequency electromagnetic wave", earthquake, "earthquake prediction"

Our transcription: Our first thought after the Loma Prieta Earthquake was that we'd probably never see our equipment again because there was a lot of damage all over that area.
Power had been lost, communication had been lost, and telephone lines were down.
We just didn't know what had happened down there.
Remarkably, Frasier-Smith's equipment survived in tact, and when one of his colleagues checked out the data that had been reported just prior to the quake, he found something unexpected and quite extraordinary.
There were very big signals coming through, and the thing that most excited him was a big increase about three hours before the earthquake where the signals had grown so large that the computer that runs our system was putting out warning messages saying that these signals were now so large that we no longer could trust the data.
The measurements were actually smaller than the real signals were.
They were no longer capable of following the real signals.
What is intriguing about these fluctuations in the electromagnetic signals is that they may have been related to the Loma Prieta Earthquake.
Frasier-Smith is quick to point out, however, that it's too early to claim that they can definitely be considered earthquake precursors.

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