双语：地球深处发明“年夜洋”面积相称于北冰洋
Scientists scanning the deep interior of Earth have found evidence of a vast water reservoir beneath eastern Asia that is at least the volume of the Arctic Ocean.
The discovery marks the first time such a large body of water has found in the planet’s deep mantle.
The finding, made by Michael Wysession, a seismologist at Washington University in St. Louis, and his former graduate student Jesse Lawrence, now at the University of California, San Diego, will be detailed in a forthcoming monograph to be published by the American Geophysical Union.
Looking down deep
The pair analyzed more than 600,000 seismograms—records of waves generated by earthquakes traveling through the Earth—collected from instruments scattered around the planet.
They noticed a region beneath Asia where seismic waves appeared to dampen, or“attenuate,” and also slow down slightly.“Water slows the speed of waves a little,” Wysession explained.“Lots of damping and a little slowing match the predictions for water very well.”
Previous predictions calculated that if a cold slab of the ocean floor were to sink thousands of miles into the Earth’s mantle, the hot temperatures would cause water stored inside the rock to evaporate out.
“That is exactly what we show here,” Wysession said.“Water inside the rock goes down with the sinking slab and it’s quite cold, but it heats up the deeper it goes, and the rock eventually becomes unstable and loses its water.”
The water then rises up into the overlying region, which becomes saturated with water.“It would still look like solid rock to you,” Wysession told LiveScience.“You would have to put it in the lab to find the water in it.”
Although they appear solid, the composition of some ocean floor rocks is up to 15 percent water.“The water molecules are actually stuck in the mineral structure of the rock,” Wysession explained.“As you heat this up, it eventually dehydrates. It’s like taking clay and firing it to get all the water out.”
The researchers estimate that up to 0.1 percent of the rock sinking down into the Earth’s mantle in that part of the world is water, which works out to about an Arctic Ocean’s worth of water.
“That’s a real back of the envelope type calculation,” Wysession said.“That’s the best that we can do at this point.”
The Beijing anomaly
Wysession has dubbed the new underground feature the“Beijing anomaly,” because seismic wave attenuation was found to be highest beneath the Chinese capital city. Wysession first used the moniker during a presentation of his work at the University of Beijing.
“They thought it was very, very interesting,” Wysession said.“China is under greater seismic risk than just about any country in the world, so they are very interested in seismology.”
Water covers 70 percent of Earth’s suITce and one of its many functions is to act like a lubricant for the movement of continental plates.
“Look at our sister planet, Venus,” Wysession said.“It is very hot and dry inside Venus, and Venus has no plate tectonics. All the water probably boiled off, and without water, there are no plates. The system is locked up, like a rusty Tin Man with no oil.”
中文链接（并非全文翻译）：
本报综合动静克日，美国迷信家陈说说，他们在地球深处发明一个庞年夜的，面积与北冰洋通俗年夜小的“年夜洋”。这是迷信家第一次在地表下发明如斯多的水。
华盛顿州立年夜学的地质学家迈克尔·维瑟逊和校友加州年夜学的耶西·劳伦斯互助完成的论文已宣布在美国地球物理协会的杂志上。更为存心思的是，这一庞年夜水体的地位重如果在东亚及北京的地下深处。因此迷信家把这种新的地底特征称为“北京极度”。
但是，如斯面积庞年夜的水体不年夜概有一团体管帐划使用潜艇对这一区域举行探测，缘故原因在于，所发明的这些水体均被禁闭在位于地表以下700公里到1400公里的岩石之中。
地表以下700公里到1400公里地位本应该是属于地幔层。地幔有年夜概存在如斯年夜面积的地下水吗？
中国地质迷信院地质所钻研员韩同林通知记者，东亚地区地下能否真正含有美国专家所料到的含水岩石区还需要进一步钻研。
维瑟逊提到，新发明的地下水以0.1百分的比例存在于距地表700公里到1400公里的岩石中，固然它的比例很小，可是总量估计的数字却极度庞年夜。如果进一步的勘察证明了维瑟逊的料到，那么相称于北冰洋水量的这些结晶水能否能加以开发使用呢？
韩同林说，固然理想上我们经由历程开采这些岩石经由高温消融蒸发搜集和过滤是可以获得水的，可是现在这项义务的成本将是人们承当不起的。
岩石中为何会有水呢？韩同林注释，前苏联有迷信家就曾提出，现在地球表面的水仅仅占地球总水量中的13百分，还剩87百分的水量留存在地幔里，成为赓续弥补地表水分的后备来源。
关键字：北冰洋 北冰洋动漫 我国独一注进北冰洋 注进北冰洋的河流 北冰洋的面积