随着欧洲、非洲和美洲的分裂，大西洋越来越宽

随着欧洲、非洲和美洲的分裂，大西洋越来越宽

Every year, the Americas are moving further away from Europe and Africa. The separation between the Atlantic-facing continents increases by 4 centimeters (1.6 inches) per year, but what was driving this has been a bit of a puzzler. The dividing line where new plates are formed is known as the Mid-Atlantic Ridge. A ridge is usually driven by a balancing act between the lighter and heavier parts of tectonic plates. But this is not the case for the Atlantic ocean, which is not surrounded by dense sinking plates.

每年，美洲大陆都在远离欧洲和非洲。面向大西洋的大陆之间的距离每年增加4厘米(1.6英寸)，但到底是什么原因让人有点困惑。新板块形成的分界线是中大西洋洋脊。山脊通常是由板块的较轻部分和较重部分之间的平衡作用形成的。但大西洋却不是这样，它没有被稠密的下沉板块包围。

In a new paper published in Nature, researchers suggest a new mechanism to explain this process: the region experiences an upsurge of matter from the deeper layers of our planet, which is pushing the continents apart.

在《自然》杂志发表的一篇新论文中，研究人员提出了一种新机制来解释这一过程:该地区经历了来自地球深层物质的激增，这将大陆推开。

One possibility was an upwelling of material from the mantle, the region beneath the Earth’s crust. These tend to originate at depths of 60 kilometers (37 miles) but the one driving the Mid-Atlantic Ridge is much deeper, over 10 times those depths.

一种可能是地壳下面的地幔物质上涌。它们往往起源于60公里(37英里)的深处，但驱动中大西洋脊的海底要深得多，超过这些深度的10倍。

Dr Alfredo Carpineti

To work out this mystery the team of researchers embarked on two research cruises deploying 39 seismographers at the bottom of the Atlantic ocean on each side of the ridge. This is one of the few experiments to have studied the mantle below the ocean's floor in such detail. In fact, it delivers the first large-scale and high-resolution imaging of the mantle.

为了解开这个谜团，研究人员展开了两次巡查，分别在海脊两侧的大西洋海底部署了39台地震仪。这是为数不多的对海底下地幔进行如此细致研究的实验之一。事实上，它提供了第一个大规模和高分辨率的地幔成像。

“This was a memorable mission that took us a total of 10 weeks at sea in the middle of the Atlantic Ocean. The incredible results shed new light in our understanding of how the Earth's interior is connected with plate tectonics, with observations not seen before,” lead author Dr Matthew Agius, from Università degli studi Roma Tre, said in a statement.

“这是一次令人难忘的任务，我们在大西洋中央的海上总共花了10周时间。该研究的主要作者、Università degli studi Roma Tre的马修·阿吉斯博士在一份声明中说:“这一令人难以置信的结果为我们对地球内部如何与板块构造联系的理解提供了新的线索。”

In particular, they studied how structures changed between depths of 410 and 660 kilometers (255 and 410 miles). They also observed abrupt changes to mineral phases, which suggests the presence of an upwelling.

特别是，他们研究了410到660公里(255到410英里)深度之间的结构变化。他们还观察到矿物相的突然变化，这表明存在上涌现象。

The findings suggest that the Mid-Atlantic Ridge is an active player in the plate tectonics of the region. Since, plate tectonics influence earthquakes and volcanoes, as well as sea levels, understanding their role helps us improve our planetary and climate models, leading to better warning systems for natural disasters.

研究结果表明，中大西洋洋脊是该地区板块构造活动的活跃参与者。由于板块构造影响地震和火山，以及海平面，了解它们的作用有助于我们改进我们的行星和气候模型，导致更好的自然灾害预警系统。

“This was completely unexpected. It has broad implications for our understanding of Earth's evolution and habitability,” co-author Dr Kate Rychert from the University of Southampton, added. “It also demonstrates how crucial it is to gather new data from the oceans. There is so much more to explore!”

“这完全出乎意料。它对我们理解地球的进化和可居住性有广泛的影响，”来自南安普顿大学的合著者凯特·瑞切特博士补充道。“这也表明，从海洋中收集新数据是多么重要。还有更多的东西等着我们去探索!”