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  • [ Silence ]

  • >> And I was installing GPS measurements,

  • and trying to convince local authorities

  • that a earthquake hazard should be higher up on their list.

  • [ Silence ]

  • >> They were able to provide a likely scenario in that

  • that scenario actually did happen,

  • means that probably more attention should be paid

  • to scientists when they talk to authorities about hazards.

  • [ Silence ]

  • >> Are able to measure the position of benchmarks

  • that we install in blocks, with a precision of a millimeter.

  • We repeat those measurements over time.

  • So if those benchmarks move because there is deformation

  • in the Earth's crust in preparation

  • for an earthquake, then we can see that.

  • [ Silence ]

  • If you want to know the probability of an earthquake

  • on a given fault, it's very important

  • to know how fast a strain, elastic energy if you want,

  • is building up on that fault

  • to be released in future earthquake.

  • And that's where we are measuring essentially

  • with this technique.

  • [ Silence ]

  • This technique has been out there for about 15 years

  • at the level of precision that we have today.

  • The difference now is that we're able

  • to analyze much more data much more quickly

  • than we were before.

  • So we'll also be re-measuring the benchmark

  • that we have installed in the past on that fault,

  • and be able to look at the difference before

  • versus after the earthquake, and learn about the mechanics

  • of this particular event.

  • After an earthquake it takes months, years perhaps,

  • for the whole area of the Earth's crust around the fault

  • within say, 100 kilometers

  • around the fault, to fully recover.

  • And this recovery process is very important

  • because it's telling us a lot

  • about the mechanical properties of the Earth's crust.

  • So we have to jump at every opportunity we have to do that.

  • We can only do that when there is an earthquake.

  • It's kind of a laboratory.

  • It's a natural laboratory.

  • So when the earthquake happened, we run out there to be able

  • to measure those mechanical properties;

  • something you cannot do there easily in the lab.

[ Silence ]

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B1 中級

普渡大學研究人員研究海地斷層;警告可能發生大地震。 (Purdue researchers studied Haitian fault; warned of potential for a large earthquake)

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    林宜悉 發佈於 2021 年 01 月 14 日
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