Here's What Scientists Know About the Tonga Volcano Eruption
汤加海底火山爆发对世界有什么影响？

While residents of Tonga struggle to recover from a devastating volcanic explosion that smothered the Pacific island nation with ash and swamped it with water, scientists are trying to better understand the global effects of the eruption.

一场毁灭性的火山爆发令太平洋岛国汤加笼罩在火山灰之中，并被洪水淹没，居民正在努力从中恢复，与此同时，科学家们正试图更好地了解这次火山爆发对全球的影响。

They already know the answer to one crucial question: Although it appeared to be the largest eruption in the world in three decades, the explosion of the Hunga volcano on Saturday will very likely not have a temporary cooling effect on the global climate, as some past enormous eruptions have.

他们已经知道一个关键问题的答案：尽管周六的洪阿火山爆发似乎是30年来世界上最大的一次，但它很可能不会像过去的一些大型火山爆发那样，对全球气候产生暂时的降温效应。

But in the aftermath of the event, there may be short-term effects on weather in parts of the world and possibly minor disruptions in radio transmissions, including those used by global positioning systems.

但在事件发生后，世界部分地区的天气可能会受到短期影响，无线电传输可能会遭到轻微干扰，包括全球定位系统使用的无线电传输。

The shock wave produced by the explosion, as well as the unusual nature of the tsunamis it generated, will have scientists studying the event for years. Tsunamis were detected not just in the Pacific, but in the Atlantic, Caribbean and Mediterranean as well.

爆发产生的冲击波，以及它所引发海啸的不寻常性质将使科学家们对这一事件进行多年的研究。不仅在太平洋，在大西洋、加勒比海和地中海也发现了海啸。

“Not that we weren’t aware of volcanic explosions and tsunamis,” said Lori Dengler, an emeritus professor of geophysics at Humboldt State University in California. “But to witness it with the modern array of instruments we have is truly unprecedented.”

“并不是说我们不了解火山爆发和海啸，”加州洪堡州立大学地球物理学荣休教授洛里·邓格勒说。“但是使用我们拥有的一系列现代仪器来见证它，这确实是前所未有的。”

The explosion of the underwater volcano, which is formally known as Hunga Tonga-Hunga-Haʻapai, rained hazardous ash over the region, including the Tongan capital, Nuku’alofa, about 40 miles south. The capital also experienced a four-foot tsunami and higher wave heights were reported elsewhere.

这座水下火山的正式名称为洪阿汤加-洪阿哈阿帕伊，它的爆发给该地区带来了大量危险的火山灰，包括位于该地区以南约64公里的汤加首都努库阿洛法。这座城市还经历了1.2米高的海啸，据报道，其他地方的海浪要更高。

The government called the eruption an “unprecedented disaster,” although the full scope of the damage has been difficult to determine because the explosion severed undersea telecommunications cables and ash has forced Tonga’s airports to shut down.

政府称这次火山爆发是“前所未有的灾难”，尽管目前还难以充分确定损失的严重程度，因为爆发切断了海底通讯电缆，火山灰迫使汤加机场关闭。

Beyond Tonga, though, the enormity of the explosion was readily apparent. Satellite photos showed a cloud of dirt, rock, volcanic gases and water vapor several hundred miles in diameter, and a narrower plume of gas and debris soared nearly 20 miles into the atmosphere.

然而，在汤加之外，这次爆发的威力是显而易见的。卫星照片显示，爆发形成了灰尘、岩石、火山气体和水蒸气组成的云团，直径达数百公里，还有一团较小的气体和碎片冲入大气层约30公里。

Some volcanologists drew comparisons to the catastrophic explosion of Krakatau in Indonesia in 1883 and to the most recent huge eruption, of Mount Pinatubo in the Philippines, in 1991.

一些火山学家将其与1883年印度尼西亚喀拉喀托火山的灾难性爆发，以及最近的一次大规模爆发——1991年菲律宾的皮纳图博火山爆发——进行了比较。

Pinatubo erupted for several days, sending about 20 million tons of sulfur dioxide gas into the stratosphere, or upper atmosphere. There, the gas combined with water to create aerosol particles that reflected and scattered some of the sun’s rays, keeping them from hitting the surface.

皮纳图博火山爆发了几天，将大约2000万吨的二氧化硫气体送入平流层或高层大气。在那里，气体与水结合形成气溶胶颗粒，反射和散射了部分太阳光线，使其无法照射到地面。

That had the effect of cooling the atmosphere by about 1 degree Fahrenheit (about half a degree Celsius) for several years. (It is also the mechanism of a controversial form of geoengineering: using planes or other means to continuously inject sulfur dioxide into the stratosphere to intentionally cool the planet.)

这使得大气温度在数年内下降了约半摄氏度。（这也是一种有争议的地球工程的机制：使用飞机或其他手段不断向平流层注入二氧化硫，有意给地球降温。）

The Hunga eruption “was matching the power of Pinatubo at its peak,” said Shane Cronin, a volcanologist at the University of Auckland in New Zealand who has studied earlier eruptions at the volcano.

新西兰奥克兰大学的火山学家沙恩·克罗宁说，洪阿火山的爆发“与皮纳图博火山的爆发高峰期威力相当”。克罗宁曾研究过这座火山的早期爆发。

But the Hunga eruption lasted only about 10 minutes, and satellite sensors in the days that followed measured about 400,000 tons of sulfur dioxide reaching the stratosphere. “The amount of SO2 released is much, much smaller than, say, Mount Pinatubo,” said Michael Manga, an earth sciences professor at the University of California, Berkeley.

但是，洪阿火山的爆发只持续了大约10分钟，随后几天，卫星传感器测量到约40万吨二氧化硫进入平流层。加州大学伯克利分校的地球科学教授迈克尔·曼加格表示：“二氧化硫的释放量比皮纳图博山等地要小得多。”

So unless the Hunga eruption resumes and continues at a similarly strong level, which is considered unlikely, it won’t have a global cooling effect.

因此，除非洪阿火山再次爆发，并以同样强烈的水平持续爆发（这被认为是不可能的），否则不会对全球产生降温效应。

Dr. Cronin said the power of the eruption was in part related to its location, about 500 feet underwater. When superhot molten rock, or magma, hit seawater, the water instantly flashed into steam, expanding the explosion many times over. Had it been much deeper, water pressure would have damped the explosion.

克罗宁说，这次火山爆发的威力部分与其位置有关，它位于水下约150米。当超热的熔岩或岩浆撞击到海水时，水立即变成蒸汽，使爆发扩大许多倍。如果它位于更深的地方，水压就能阻止爆发。

The shallower depth created perfect “almost Goldilocks” conditions, he said, to supercharge the explosion.

他说，较浅的深度创造了完美的“几乎恰到好处”的条件使爆发威力增加。

The blast produced a shock wave in the atmosphere that was one of the most extraordinary ever detected, said Corwin Wright, an atmospheric physicist at the University of Bath in England. Satellite readings showed that the wave reached far beyond the stratosphere, as high as 60 miles up, and propagated around the world at more than 600 miles an hour.

英格兰巴斯大学的大气物理学家科温·赖特表示，这次爆炸在大气中产生了一次冲击波，这是迄今为止探测到的最不寻常的冲击波之一。卫星读数显示波动远远超出了平流层，高达96公里，并以每小时960多公里的速度在世界范围内传播。

“We’re seeing a really big wave, the biggest we’ve ever seen in the data we’ve been using for 20 years,” Dr. Wright said. “We’ve never seen anything really that covers the whole Earth like this, and certainly not from a volcano.”

“我们看到了一个巨大的波动，这是我们在使用了20年的数据中所见过最大的，”赖特说。“我们从未见过像这样真的覆盖了整个地球的东西。它来自火山，这当然也是前所未见的。”

The wave resulted when the force of the blast displaced huge amounts of air outward and upward, high into the atmosphere. But then gravity pulled it down. It then rose up again, and this up-down oscillation continued, creating a wave of alternating high and low pressure that moved outward from the blast source.

当爆炸的力量将大量空气向外和向上推到大气中时就会产生这样的波动。但随后重力将其向下拉。然后它再次上升，这种上下振荡继续，产生一波交替的高低压，从爆炸源向外移动。

Dr. Wright said that although the wave occurred high in the atmosphere, it may potentially have a short-term effect on weather patterns closer to the surface, perhaps indirectly by affecting the jet stream.

赖特说，尽管波动发生在大气中的高处，但它也许会对靠近地表的天气模式产生短期效应，这种效应可能由受到影响的急流间接引发。

“We don’t quite know,” he said. “We’re looking to see what happens over the next few days. It could just sort of ripple through and not interact.”

“我们不太清楚，”他说。“我们希望看看接下来几天会发生什么。它可能只是扩散，而不是相互作用。”

Dr. Wright said that because the wave was so high, it could also potentially have a slight effect on radio transmissions and signals from global positioning systems satellites.

赖特说，由于冲击波非常高，可能还会对全球定位系统卫星的无线电传输和信号产生轻微影响。

The atmospheric pressure wave may have also played a role in the unusual tsunamis that occurred.

大气压力波也可能对异常海啸的发生发挥了作用。

Tsunamis are generated by the rapid displacement of water, usually by the movement of rock and soil. Large underwater faults can generate tsunamis when they move in an earthquake.

海啸是由水的快速置换产生的，通常是由岩石和土壤的运动引起的。大型水下断层在地震中移动时会产生海啸。

Volcanoes can cause tsunamis as well. In this case, the underwater blast, and the collapse of the volcano’s crater, may have caused the displacement. Or one flank of the volcano may have become unstable and collapsed, with the same result.

火山也会引发海啸。在这种情况下，水下爆炸和火山口的坍塌可能导致了位移。或者火山的一侧可能变得不稳定并坍塌，都会引发海啸。

But that would only account for the local tsunami that inundated Tonga, scientists said. Ordinarily, said Gerard Fryer, an affiliate researcher at the University of Hawaii at Manoa who formerly worked at the Pacific Tsunami Warning Center, “you’d expect that energy to decay away with distance.”

但科学家说，这只能解释淹没汤加的当地海啸。夏威夷大学马诺阿分校附属机构研究员、曾在太平洋海啸预警中心工作的杰拉德·弗莱尔说，通常情况下，“你会认为这种能量会随着距离的增加而减弱。”

But this event generated tsunamis of roughly the same size as the local one, and over many hours, in Japan, Chile and the West Coast of the United States, and eventually generated small tsunamis in other basins elsewhere around the world.

但这一事件在日本、智利和美国西海岸产生了与当地大小大致相同的海啸，并持续了数小时，并最终在世界其他地方的内湾产生了小型海啸。

That’s a sign that as it traveled through the atmosphere, the pressure wave may have had an effect on the ocean, causing it to oscillate as well.

这表明当它在大气层中穿过时，压力波可能对海洋产生了影响，导致它也发生了振荡。

It will take weeks or months of analyzing data to determine if that’s what happened, but some researchers said it was a likely explanation.

仍需要数周或数月的数据分析才能确定是否发生了这种情况，但一些研究人员表示，这是一个可能的解释。

“We know that the atmosphere and the ocean are coupled,” said Dr. Dengler. “And we see the tsunami in the Atlantic Ocean. It didn’t go around the tip of South America to get there.”

“我们知道大气和海洋是相连接的，”邓格勒说。“我们在大西洋看到了海啸。它并不是绕过南美洲南端到达那里的。”

“The evidence is very clear that the pressure wave played a role. The question is how big a part.”

“证据非常清楚，压力波起了作用。问题是它的作用有多大。”

来源：好英语网