字幕列表 影片播放 列印英文字幕 [ 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.
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) 4 0 林宜悉 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字