黃石超級火山或將提前噴發，你需要知道這些事

你大概聽說過美國的黃石國家公園有一座超級火山吧。那你知道嗎，這個超級定時炸彈的爆發時間或許比很多人預想的要早得多，留給美國人民的預警時間也很短。

亞利桑那州立大學的科研人員耗時數周時間，分析了黃石公園火山的石化火山灰沉積物，相關發現已于近日對外公布。這些沉積物中的礦物質成份表明，這座火山的溫度和構造就只需要幾十年可以積累到瀕臨噴發的程度，而不是像科學家預想的那樣需要幾千年的時間。

研究團隊中的亞利桑那州立大學研究生漢納?夏姆魯對《紐約時報》表示：“一個火山系統從靜止到臨近噴發，只需要這么短的時間，實在令人震驚?！?/p>

這番話從一個火山專家口中說出來，是相當值得警醒的。好消息是，科學家們再研究上幾十年，大概就可以精確地預測火山的下次噴發會在什么時候發生了。

有的時候，人知道得越多，就對自己的生活和生命越有掌控感。然而有些時候，人知道的越多，只會讓你在自然之力面前愈發感到自己的渺小與無助，尤其是美國人民屁股下面還坐著這么一塊稟性無常的大石頭。

下面是關于這座超級火山的一些小科普，它可能會讓你覺得寬心一些，也有可能讓你更憂心。

黃石火山是唯一一座我們應該擔心的超級火山嗎？

當然不是了。除了黃石這個“超級炸藥包”，全球大約還有20多座超級火山，其中還有三座在美國?？茖W家們認為，這三座中的一座平均每10萬年左右就會噴發一次。

雖然黃石火山近63.1萬年都沒有超級噴發過，但近來進入活躍期的超級火山卻并非沒有。比如意大利有一座坎皮弗萊格瑞火山（Campi Flegri），這個名字翻譯過來，就是“燃燒的土地”的意思。它在一萬五千年前剛剛噴發過。

意大利的科研人員指出，坎皮弗萊格瑞火山已經進入了“臨界狀態”，也就是說它馬上就要噴發了。但此次噴發的規?；驅⑦h遠不及三萬九千年的那一次。那次這座火山共噴射了相當于72立方英里的熔巖（又叫坎帕階熔灰巖）。我們的遠親尼安德特人的滅絕，或許就與這次災難不無關系。

黃石火山的噴發將使哪些地區受到影響？

如果黃石超級火山噴發了，它可能會向空中噴射出1000立方千米以上的熔巖和火山灰。

換算過來就是250立方英里，比意大利的那次滅絕性的噴發還要嚴重三倍。要知道，意大利的那次超級噴發形成的硫磺云甚至飄到了1200英里以外的俄羅斯。再舉個例子，黃石超級火山噴發的威力，大約相當于1980年圣海倫斯火山爆發的2500倍，在那次事故中有57人遇難。

黃石超級火山的爆發將形成方圓500英里以上的火山灰云，幾乎能夠覆蓋整個美國西部。

黃石火山爆發的威力之大，或將使整個地球陷入一個“火山冬天”。也就是說，種莊稼什么的就別想了。據聯合國2012年的估算，我們現有的糧食儲備將只能維持74天。（不過隨著農業技術的不斷創新，說不定我們能在地底下種糧食。）

超級火山是否會導致人類滅絕？

在人類滅絕的各種版本里，火山爆發排在第幾名呢？據NASA稱，超級火山爆發對地球生命的威脅，要遠遠大于任何小行星撞擊的風險。

好在NASA也不是吃素的，它也有一套應對超級火山威脅的方案。這個法子跟民間偏方的放血療法差不多，大約要耗資34億美元，在火山上鉆一個6英里的窟窿，好把憋在地底的熱量釋放出來一些，希望這樣能避免火山的激烈噴發。

這個計劃說不定能讓超級火山冷卻個幾百年甚至幾千年。它還有另一個好處——能為我們提供大量的地熱能。當然，搬石頭砸自己的腳的風險也是有的。一個不小心，說不定會把這座超級火藥庫提前引爆了。

黃石超級火山爆發的概率是多少？

雖然這項研究表明，導致超級火山噴發的條件只需要幾十年就能形成，但是你這輩子親歷一次史詩級別的超級大噴發的機率還是很低的。

據美國地質調查局介紹，黃石超級火山在某一特定年份里噴發的概率只有七十三萬分之一。這個機率比你中彩票的概率要高一些，不過比你遭雷劈的概率還是要低那么一丟丟。（財富中文網）

譯者：賈政景

Did you know there’s a supervolcano in Yellowstone National Park? Maybe you’ve heard that it could erupt with much less advance warning than expected?

Researchers from Arizona State University spent weeks studying fossilized ash deposits from the Yellowstone volcano and recently shared their findings. The minerals in these deposits revealed that the critical changes in temperature and composition preceding an eruption build up over a matter of decades, rather than thousands of years as scientists originally thought.

“It’s shocking how little time is required to take a volcanic system from being quiet and sitting there to the edge of an eruption,” Hannah Shamloo, a graduate student at Arizona State University who worked on the research, told The New York Times.

This is an alarming thing for a volcanologist to say. The good news is that scientists are likely just decades away from being able to more accurately predict when an eruption would occur.

Sometimes knowing more about the world around us makes us feel more in control of our lives and survival. And sometimes knowing more only underscores how small and helpless we are compared to the forces of nature on the angry rock where we reside.

Here are some more facts about supervolcanoes that may or may not make you feel any better.

Is Yellowstone the only supervolcano to worry about?

No, of course not. There are about 20 others around the world and three others, besides the Yellowstone supervolcano, in the U.S. Scientists suspect that one of them erupts every 100,000 years or so.

While Yellowstone hasn’t had a super-eruption in 631,000 years, others have been active more recently. Campi Flegri, a supervolcano in Italy whose name translates to “burning fields,” had a super-eruption 15,000 years ago.

Campi Flegri is in a “critical state,” according to researchers in Italy. It’s due for an eruption soon, but it would be a minor event compared to the 72 cubic miles of molten rock it spewed in its most notorious eruption 39,000 years ago, called Campanian Ignimbrite, that likely contributed to the extinction of the Neanderthals.

What areas would a Yellowstone eruption affect?

If the Yellowstone supervolcano erupts, it could shoot out more than 1,000 cubic kilometers of rock and ash into the air.

That’s 250 cubic miles. That’s more than three times as large as the Campanian Ignimbrite eruption in Italy, which created a sulfurous cloud that floated more than 1,200 miles away to hang over Russia. That’s 2,500 times more material than Mount St. Helens expelled in 1980, killing 57 people.

An eruption at Yellowstone would result in a cloud of ash more than 500 miles wide, stretching across nearly the entire western United States.

The explosion could be so incredibly large that it could plunge the entire planet into a volcanic winter. That means it would be impossible to grow crops and current food stores would only last about 74 days, according to a 2012 estimate by the United Nations (though innovations in farming may mean that food could be grown underground).

Will a supervolcano eruption end life on Earth?

None of this sounds ideal, but how does it rank in terms of apocalyptic near-future possibilities? According to NASA, supervolcano eruptions are a bigger danger to life on Earth than any asteroid.

Luckily NASA has a plan to neutralize supervolcano threats. It would cost approximately $3.4 billion and involves drilling down just over 6 miles into the volcano in order to release heat and hopefully avoid a violent eruption.

This plan could cool the supervolcano over the course of hundreds or even thousands of years. There’s another bonus: It would become a source of geothermal energy, too. But there are considerable risks, too. It could trigger the eruption it’s meant to save us from.

How likely is it that the Yellowstone supervolcano will erupt?

Despite the fact that this new research shows conditions leading up to supervolcano eruption could occur in several decades, the chances that you will personally experience an explosion of this scale are still low.

The odds of the Yellowstone supervolcano erupting within a given year are one in 730,000, according to the U.S. Geological Survey. Here’s a little perspective: Those odds are significantly better than your chances of winning the lottery and only slightly worse than the chance you’ll be struck by lightning.