地球冰川的消逝將改變你對過去50年的看法

地球冰川的消逝將改變你對過去50年的看法

New timelapse videos from satellites that have been monitoring Earth for decades have revealed the shocking reality of ice melting at accelerated speeds all over our planet.

幾十年來一直在監(jiān)測地球的衛(wèi)星拍攝的最新時間間隔視頻揭示了一個令人震驚的事實:地球上所有的冰都在加速融化。

The series focuses on glaciers and ice sheets in Alaska, Greenland and Antarctica, showing how, over the decades, most of the ice is retreating annually and not growing back.

該系列聚焦于阿拉斯加、格陵蘭島和南極洲的冰川和冰原，展示了在過去幾十年里，大部分冰川每年都在退縮，而不是重新生長。

I think observational glaciology in terms of remote sensing is a very data-rich field now, compared to 1972, when you had a few images, says glaciologist Mark Fahnestock of the University of Alaska Fairbanks.

阿拉斯加費爾班克斯大學的冰川學家馬克·法赫內(nèi)斯托克說:“我認為，從遙感的角度來看，觀測冰川學現(xiàn)在是一個數(shù)據(jù)非常豐富的領域。

So we are beginning to get a historical record of the speeds of glaciers, and so we can watch how rapidly that surface is lowering as things speed up, or where it's thickening.

“所以我們開始獲得冰川速度的歷史記錄，這樣我們就可以看到隨著速度的加快，冰川表面下降的速度有多快，或者冰川在哪里變厚。”

Using Landsat images dating back to 1972 and continuing all the way up to this year for a total of nearly 48 years, Fahnestock created six-second timelapses of all the glaciers in Alaska and Yukon. While some of the ice masses grow over that time, most of them shrink quite shockingly.

Fahnestock使用的是1972年的Landsat圖像，一直延續(xù)到今年，歷時近48年，創(chuàng)造了阿拉斯加和育空地區(qū)所有冰川的6秒鐘時間。雖然有些冰塊在這段時間內(nèi)不斷增大，但大多數(shù)都縮小得相當驚人。

It is, according to scientists, a clear illustration of the havoc being wreaked by climate change. You see, for instance, the Columbia glacier remaining stable until about the mid-1980s, when it starts disintegrating and retreating into the Chugach Mountains. It's now one of the most rapidly changing glaciers in the world.

據(jù)科學家說，這是氣候變化造成的嚴重破壞的一個清楚的例子。例如，你可以看到，哥倫比亞冰川在20世紀80年代中期之前一直保持穩(wěn)定，直到它開始瓦解并退縮到丘加奇山脈。它現(xiàn)在是世界上變化最快的冰川之一。

Not even the growing glaciers are in the clear, such as the Hubbard glacier in eastern Alaska. Towards the end of the timelapse, a large chunk of the glacier calves into the ocean.

甚至連阿拉斯加東部的哈伯德冰川(Hubbard glacier)這樣不斷增大的冰川也無法清晰地看到。時間快到盡頭時，一大塊冰川崩裂成兩半，流入大海。

That calving embayment is the first sign of weakness from Hubbard Glacier in almost 50 years - it's been advancing through the historical record, Fahnestock said. "The satellite images also show that these types of calving embayments were present in the decade before Columbia retreated."

法赫內(nèi)斯托克說:“這是近50年來哈伯德冰川首次出現(xiàn)冰川崩解的跡象，它一直在打破歷史記錄。”“衛(wèi)星圖像還顯示，在哥倫比亞號撤退之前的十年間，就存在這種類型的冰解灣。”

Things weren't much better in Greenland where, according to satellite data collected between 1985 and 2018, glaciers retreated by five kilometres (three miles) on average, speeding up quite noticeably after 2000, with the ice losing more mass than it gains. And the phenomenon is not geographically constrained.

格陵蘭島的情況也好不到哪兒去。根據(jù)1985年至2018年收集的衛(wèi)星數(shù)據(jù)，那里的冰川平均退縮了5公里(3英里)，2000年之后明顯加速，冰的質(zhì)量減少的比增加的多。而且這種現(xiàn)象并不受地理限制。

One thing we've noticed is that retreat has been a pattern that we've seen across the ice sheets in Greenland, said glaciologist Michalea King of The Ohio State University. "It's not just limited to one region."

俄亥俄州立大學的冰川學家Michalea King說:“我們注意到的一件事是，退縮是我們在格陵蘭冰蓋上看到的一種模式。”“這不僅僅局限于一個地區(qū)。”

This retreat at glacial toes - or the ends of the glaciers - was accompanied by meltwater ponds (pictured below) appearing at higher and higher altitudes.

冰川腳趾處——或冰川的末端——的退縮伴隨著融水池塘(見下圖)出現(xiàn)在越來越高的海拔。

We looked at how many lakes there are per year across the ice sheet and found an increasing trend over the last 20 years: a 27 percent increase in lakes, said glaciologist James Lea of the University of Liverpool in the UK. "We're also getting more and more lakes at higher elevations - areas that we weren't expecting to see lakes in until 2050 or 2060."

英國利物浦大學的冰川學家詹姆斯·李說:“我們研究了冰原上每年有多少個湖泊，發(fā)現(xiàn)在過去20年里湖泊數(shù)量呈上升趨勢:增加了27%。”“我們也在越來越多的高海拔地區(qū)發(fā)現(xiàn)湖泊，而這些地區(qū)直到2050年或2060年才會出現(xiàn)湖泊。”

And, down in Antarctica, microwave radar images revealed lakes of liquid water beneath the ice and snow, which remain liquid even in the depths of winter. These lakes can destabilise ice shelves, accelerating their calving.

而且，在南極洲，微波雷達圖像顯示冰和雪下有液態(tài)水的湖泊，即使在隆冬也保持液態(tài)。這些湖泊會破壞冰架的穩(wěn)定，加速冰架的崩解。

We've known of such lakes beneath both Antarctica and the Greenland ice sheet; but the researchers' data suggest there may be more subglacial lakes in Antarctica than we knew about, suggesting that the loss of the ice shelves may be more advanced.

我們知道在南極洲和格陵蘭冰蓋下都有這樣的湖泊;但研究人員的數(shù)據(jù)表明，南極洲可能有比我們所知道的更多的冰下湖泊，這表明冰架的消失可能更早。

Put all together, the decades of satellite data show a trend that is not limited by region: the world's permanent ice is melting, and these videos demonstrate that stark reality more clearly than ever before.

總而言之，幾十年的衛(wèi)星數(shù)據(jù)顯示了一種不受地域限制的趨勢:世界上永久性的冰正在融化，而這些視頻比以往任何時候都更清楚地展示了這一嚴酷的現(xiàn)實。

It's just one of many, many signs that Earth is undergoing rapid climate change; it's not too late to do something about it.

這只是地球正在經(jīng)歷快速氣候變化的眾多跡象之一;現(xiàn)在采取行動還不晚。

The researcher was presented at the 2019 Fall Meeting of the American Geophysical Union.

該研究人員出席了2019年秋季的美國地球物理聯(lián)盟會議。