大千世界 死亡冰柱 所到之處瞬間冰封...

死亡冰柱 所到之處瞬間冰封

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死亡冰柱所到之處瞬間冰封

南極長年冰天雪地,人跡罕至,不少奇怪異象都是世人從未見過,英國廣播公司( BBC)攝製隊,早前首次在南極海底拍攝到“死亡冰柱”( icicle of death),冰柱下沉到海床後,所到之處周遭的海水都會凝結,海膽、海星全被凍死,蔚為奇觀。

其實這種死亡冰柱自1960年代已開始存在,通常當南極海洋混入了帶鹽份的水後就會出現,不過今次還是首度有人拍攝到這個奇景。拍攝當日,海底水溫只得-2℃,BBC攝影師米勒( Hugh Miller)及安德森( Doug Anderson)在南極羅斯群島( Ross Archipelago)的小剃刀背島( Little Razorback Island)海中,親眼目擊死亡冰柱的形成過程。由於冰柱的密度較海水高,因此一直朝海床沉下,並迅速擴張,周遭接觸到冰柱的海水隨即變冷凝固,但看上去像海綿狀多過普通海冰,而附近的海洋生物,如海膽及海星等,因冰柱的溫度太低而全被凍死。

米勒憶述當日親眼目擊冰柱沉下並迅速擴張,仍感到有點難以置信,“這情況有點像與時間競賽,因為沒有人真正知道它們形成得有多快。我們一星期前看到的那條冰柱,在我們面前迅速擴張變長,整個過程只用了5、6小時”

Remarkable broadcast moment: The ice begins to expand outwards. The brine is a lot more dense than seawater so sinks to the bottom. It is also a lot colder- causing the freezing

Touchdown: The brinicle reaches the ocean floor.Starfish can be seen. Often the brinicles break up before they become so large

Killer: The ice floods outwards across the ocean surface rapidly, destroying everything in its wake

Destruction: The starfish are frozen by the ice as it expands outwards

Broadcasting feat: Although the existence of brinicles has long been known it is the first time they have ever been caught on camera

Seabed spread: When the seawater freezes as it comes into contact with the brinicle it is a lot more spongelike than normal ice

(责任编辑:文恩)

(文章来源:网络转载)

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