磁北以每年30英里的速度移動，可能是磁極翻轉(zhuǎn)的信號

磁北以每年30英里的速度移動，可能是磁極翻轉(zhuǎn)的信號

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.

無論你什么時候拿著指南針，指針都指向北極附近的磁北極。幾個世紀(jì)以來，磁北極一直引領(lǐng)著航海家和探險家們周游世界。

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

但是，北極地磁目前的移動速度比人類歷史上任何時候都要快。

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)的速度移動。從1900年到1980年，它并沒有發(fā)生太大的變化，但在過去的40年里，它確實加速了。”

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)的五年更新本應(yīng)在2020年進行，但在美國軍方要求提前審查后，這一更新被提前了。經(jīng)過一年的調(diào)整，WMM于12月10日發(fā)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.

新模型預(yù)測，北極將繼續(xù)向俄羅斯漂移，盡管速度會緩慢下降——從過去20年平均每年55公里(約34英里)的速度下降到每年40公里左右。這個模型是美國國家環(huán)境信息中心(NCEI)和英國地質(zhì)調(diào)查局的工作成果，NCEI是美國國家海洋和大氣管理局的一部分。

Why it matters

為什么它很重要

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.

正在發(fā)生的變化給航空、導(dǎo)航和利用地球磁場定位的遷徙動物帶來了重大問題。一些機場甚至更改了跑道的名稱，以更好地對應(yīng)它們當(dāng)前相對于磁北極的方向。

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.

自從1831年磁北極首次被發(fā)現(xiàn)以來，地質(zhì)學(xué)家們一直在追蹤它的進程。與真北不同(以地軸為標(biāo)志)，地磁北極由于地球熔融內(nèi)核的變化而不斷移動，內(nèi)核中含有鐵。在有記錄以來的大部分時間里，北極一直位于或環(huán)繞加拿大冰雪覆蓋的埃爾斯米爾島，但如果以目前的速度移動，用不了多久，它就會位于俄羅斯上空。

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，真正使南極目前的運動如此不同尋常的是它移動的速度。僅在過去的十年里，人口流動就增加了三分之一，每五年就有一度左右的偏差。

Will the north pole eventually flip?

北極最終會翻轉(zhuǎn)嗎?

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.

磁極位置的迅速變化促使一些專家推測，地球的整個磁場可能正準(zhǔn)備“翻轉(zhuǎn)”，所有的羅盤都將倒轉(zhuǎn)，指向南而不是北。這可能聽起來很激進，但在地質(zhì)年代，磁極轉(zhuǎn)換是比較常見的。雖然它們通常每40萬年左右發(fā)生一次，但自上次翻轉(zhuǎn)以來已經(jīng)過去了78萬年。

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.

科學(xué)家們對磁極轉(zhuǎn)換將如何影響全球生態(tài)系統(tǒng)存在分歧，但一些危言聳聽者警告說，一場改變地球的災(zāi)難即將來臨，地震和巨大的海嘯將在幾十年內(nèi)威脅地球。美國國家航空航天局表示，雖然不能完全排除這種激進的末日預(yù)言，但絕大多數(shù)科學(xué)家的預(yù)測較為溫和。

"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."

美國地質(zhì)勘探局的杰弗里·洛夫說:“通常情況下，地球磁極轉(zhuǎn)換需要一萬年左右的時間。”一萬年前，人類還沒有文明。這些過程很緩慢，因此我們沒有什么可擔(dān)心的。”