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  • "Offer a magnificent view of nature's greatest power display."

  • Mount Mayon in the Philippines erupted in January.

  • It continued for over a month.

  • In February, Mount Sinabung erupted in Indonesia.

  • Here's the ash cloud as seen from space.

  • And in June an eruption in Guatemala killed more than 100 people.

  • Turns out this is pretty normal.

  • On average, there are 10 to 20 volcanoes erupting around the world at any given time.

  • When you look at these on a map and add volcanoes that are not currently erupting,

  • you'll start to see a pattern.

  • Most are concentrated here, along the edges of the Pacific Ocean.

  • This region is known as the Ring of Fire, a stretch of hundreds of volcanoes spanning

  • 40,000 kilometers.

  • It's also where most of the earthquakes and tsunamis in the world take place.

  • This year alone, the region saw 4 eruptions and 5 of the world's biggest earthquakes .

  • The Ring of Fire is where some of history's most devastating natural disasters have happened

  • and will continue to happen.

  • "There are still some volcanoes around the world

  • in various places. Do you know where they are?

  • Here's a map, see if you can find some."

  • Volcanoes have terrorized people for centuries.

  • In the 1800s, explorers and scientists started grouping them together.

  • Take a look at this map from 1852.

  • It hasthe volcanic series of Australia”.

  • And "the volcanic series of Japan and Kamchatka, in Russia."

  • In fact, the whole Ring of Fire is marked here.

  • Scientists recognized the belt of activity, but it would take another 100 years until

  • they agreed on what caused it.

  • "That's right, it's a volcano. Well, you see what you and I are going to talk about today is the world under our feet."

  • By the 1960s, most scientists concluded the earth's surface is made up of a series of tectonic plates

  • that slowly move into and apart from each other.

  • Take a look at the plates that make up the

  • Pacific.

  • Now look at where the eruptions and earthquakes occur.

  • The Ring of Fire is the result of these plates crashing into each other.

  • "One in Japan, that's right. Fujiyama. There's some others in the south Pacific.

  • How about in our part of the world?"

  • "Mexico." "That's right, there's several in Mexico."

  • The plates in the Pacific are moving faster than other plates around

  • the world, adding stress where the plates interact.

  • This plate is moving northwest, crashing into the North American plate, which explains all

  • the volcanoes here.

  • Over in California, the Pacific plate is grinding past the North American Plate -- where they

  • meet is called the San Andreas Fault.

  • The movement causes thousands of earthquakes a year.

  • A few of them are even large enough to cause serious damage.

  • Like the San Francisco-Oakland earthquake in 1989, which killed 63 people and injured

  • nearly 4,000.

  • All these plate interactions are independent

  • from each other.

  • But when grouped together, they make up the most seismically active region in the world.

  • "Remember a little while ago an island blew up and disappeared?" "Oh yeah."

  • "That was because of a volcano."

  • The problem with the Ring of Fire is that geologists can't accurately predict when

  • a volcano is going to erupt or an earthquake will shake the ground.

  • They can monitor tremors, gas emissions and temperature changes around a volcano to estimate

  • when it might erupt, but they can't be sure of the exact timing or the severity.

  • And those predictions get even weaker with earthquakes which aren't preceded by any warning signs,

  • so we can't even see them coming.

  • One way scientists forecast the future of these phenomena is by looking at the past

  • -- take New Zealand for example:

  • Earthquakes have occured on this fault line every 500 to 1,000 years.

  • There was a massive quake over 800 years ago and another one around the 500 mark.

  • So scientists now believe New Zealand is due for mega quake.

  • Over here in California, there is a 72% chance of a major earthquake

  • along northern section of the San Andreas

  • faultline in the next 30 years.

  • Parts of Japan have a 25% chance of a big quake and Seattle could see one in the next

  • 50 years that could impact 7 million people.

  • In fact many countries along the Ring of Fire will continue to be at risk for the foreseeable

  • future.

  • They can't get out of harm's way, but there is something they can do about it.

  • In 2011, an earthquake and a following tsunami, killed 15,000 people and caused $300 billion

  • in damages in Japan.

  • But those numbers could've been a lot higher.

  • See, Japan requires buildings be constructed with anti-earthquake designs, like the one

  • in this video.

  • And it has an early warning system that stopped high-speed trains, factory lines, and sent

  • countrywide text alerts a full minute before the tremor hit.

  • While Japan's precautions didn't prevent the disaster, they did save countless lives.

  • The problem is, not every country in the Ring of Fire is like Japan.

  • Most of these countries have some form of anti-earthquake building code, but the quality

  • and implementation of these codes varies.

  • And none of these countries have early warning systems for earthquakes.

  • In developing countries, funding these projects can be a problem.

  • But even richer countries aren't taking the risk seriously enough.

  • California, Oregon, Washington. Some of the most vulnerable states in the US, still

  • don't have a public early-warning system in place.

  • Because volcanoes and earthquakes continue to be unpredictable threats, governments tend

  • to treat them as a low priority.

  • And that's what makes the Ring of Fire even more dangerous.

  • We know for certain that there will be more natural disasters along this belt.

  • What we don't know is if we'll be prepared for them.

  • "Future studies will surely improve the clarity with which scientists view the interior of the Earth

  • and will help people accomodate their activities

  • to these powerful, sometimes destructive, often beneficial, always fascinating neighbors.

"Offer a magnificent view of nature's greatest power display."

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B1 中級 美國腔

太平洋周邊為什麼會有一圈自然災害? (Why there's a ring of natural disasters around the Pacific)

  • 185 5
    Amy.Lin 發佈於 2021 年 01 月 14 日
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