磁北以每年30英里的速度移动，可能是磁极翻转的信号

磁北以每年30英里的速度移动，可能是磁极翻转的信号

Whenever you hold a compass, the needle points to magnetic north near the North Pole. For centuries, magnetic north has led navigators and explorers around the world.

无论你什么时候拿着指南针，指针都指向北极附近的磁北极。几个世纪以来，磁北极一直引领着航海家和探险家们周游世界。

But the magnetic north pole is currently shifting at a faster rate than at any time in human history.

但是，北极地磁目前的移动速度比人类历史上任何时候都要快。

Magnetic north in the Arctic Circle is shifting so quickly now that it's affecting navigation. (Photo: nenets/Shutterstock)

"It's moving at about 50 km (30 miles) a year. It didn't move much between 1900 and 1980 but it's really accelerated in the past 40 years," Ciaran Beggan, of the British Geological Survey in Edinburgh, told Reuters.

“它正以每年50公里(30英里)的速度移动。从1900年到1980年，它并没有发生太大的变化，但在过去的40年里，它确实加速了。”

A five-year update of the World Magnetic Model (WMM) was due in 2020, but that was moved up after the U.S. military requested an early review. A new update to the WMM was released on Dec. 10, following a year of adjustments.

世界磁模型(WMM)的五年更新本应在2020年进行，但在美国军方要求提前审查后，这一更新被提前了。经过一年的调整，WMM于12月10日发布了新的更新。

The new model forecasts the northern magnetic pole will continue drifting toward Russia, although at a slowly decreasing speed — down to about 40 kilometers per year compared to the average speed of 55 kilometers (roughly 34 miles) over the past 20 years. The model is the work of the National Centers for Environmental Information (NCEI), which is part of NOAA, and the British Geological Survey.

新模型预测，北极将继续向俄罗斯漂移，尽管速度会缓慢下降——从过去20年平均每年55公里(约34英里)的速度下降到每年40公里左右。这个模型是美国国家环境信息中心(NCEI)和英国地质调查局的工作成果，NCEI是美国国家海洋和大气管理局的一部分。

Why it matters

为什么它很重要

This is a global map of declination and the dip pole locations for 2020. (Photo: NOAA NCEI/CIRES)

The ongoing changes are causing major problems for aviation, navigation and migratory animals that use the Earth's magnetic field to orient themselves. Some airports have even changed the names of their runways to better correspond to their current direction relative to magnetic north.

正在发生的变化给航空、导航和利用地球磁场定位的迁徙动物带来了重大问题。一些机场甚至更改了跑道的名称，以更好地对应它们当前相对于磁北极的方向。

Ever since the magnetic north pole was first discovered in 1831, geologists have been tracking its progress. Unlike true north (which is marked by the Earth's axis), magnetic north is constantly on the move due to changes in the planet's molten core, which contains iron. Throughout most of recorded history, the pole has been positioned at or around Canada's icy Ellesmere Island, but if it keeps moving at its current rate, it won't be long before it sits above Russia instead.

自从1831年磁北极首次被发现以来，地质学家们一直在追踪它的进程。与真北不同(以地轴为标志)，地磁北极由于地球熔融内核的变化而不断移动，内核中含有铁。在有记录以来的大部分时间里，北极一直位于或环绕加拿大冰雪覆盖的埃尔斯米尔岛，但如果以目前的速度移动，用不了多久，它就会位于俄罗斯上空。

The thing that really makes the pole's current movement so unusual, however, is the speed at which it's shifting. In the last decade alone, movement has increased by a third, throwing off compasses by roughly 1 degree every five years.

然而，真正使南极目前的运动如此不同寻常的是它移动的速度。仅在过去的十年里，人口流动就增加了三分之一，每五年就有一度左右的偏差。

Will the north pole eventually flip?

北极最终会翻转吗?

The rapid shifting of the pole's position has prompted some experts to speculate that the Earth's entire magnetic field may be preparing to "flip," whereby all compasses invert and point south instead of north. It may sound radical, but in geological time, pole reversals are relatively common. Though they typically occur once every 400,000 years or so, it's been 780,000 years since the last flip.

磁极位置的迅速变化促使一些专家推测，地球的整个磁场可能正准备“翻转”，所有的罗盘都将倒转，指向南而不是北。这可能听起来很激进，但在地质年代，磁极转换是比较常见的。虽然它们通常每40万年左右发生一次，但自上次翻转以来已经过去了78万年。

Scientists disagree on how a pole reversal would effect ecosystems around the world, but some alarmists warn of a planet-altering catastrophe, whereby earthquakes and monumental tsunamis threaten the Earth for decades. Though such radical doomsday prophecies cannot be completely ruled out, the vast majority of scientists offer more tempered predictions, says NASA.

科学家们对磁极转换将如何影响全球生态系统存在分歧，但一些危言耸听者警告说，一场改变地球的灾难即将来临，地震和巨大的海啸将在几十年内威胁地球。美国国家航空航天局表示，虽然不能完全排除这种激进的末日预言，但绝大多数科学家的预测较为温和。

"Reversals typically take about 10,000 years to happen," said Jeffrey Love of the U.S. Geological Survey. "And 10,000 years ago civilisation did not exist. These processes are slow, and therefore we don't have anything to worry about."

美国地质勘探局的杰弗里·洛夫说:“通常情况下，地球磁极转换需要一万年左右的时间。”一万年前，人类还没有文明。这些过程很缓慢，因此我们没有什么可担心的。”