The 'Finger of Death' that Freezes Everything it Touches | Earth's Great Seasons | BBC Earth

BBC Earth

10 Sept 202403:58

Summary

TLDRIn Antarctica, the winter freeze dramatically increases the continent's size, doubling it to surpass the USA's area. A Weddell seal faces a life-threatening challenge as her breathing hole begins to freeze over, forcing her to gnaw it open to survive. Beneath the ice, a stable underwater world thrives, yet it's not immune to winter's perils. Supercooled water forms deadly briners, sinking to create icy pillars that can trap and kill seafloor creatures, turning a wonderland into a deadly trap.

Takeaways

🌐 In Antarctica, the winter freeze causes the continent to double in size, becoming larger than the USA.
❄️ The Weddell seal faces an urgent problem as the sea around her freezes, threatening her breathing hole.
🦭 To prevent suffocation, the Weddell seal uses her teeth to keep her breathing hole from freezing over.
🌡 The sea beneath the ice is a constant two degrees centigrade, which is over 50 degrees warmer than the surface.
🏰 The underwater environment is described as an 'enchanted kingdom', protected from the extreme temperatures above.
🌿 Life thrives in this stable and safe underwater world, with abundant biodiversity.
❄️ Winter cold can still impact this underwater world, as plummeting surface temperatures trigger the growth of 'briners'.
💧 Briners are cold, supercooled water sinking from above, forming pillars of ice that can be deadly to seafloor creatures.
🌊 These ice pillars act like a 'river of ice', imprisoning everything in their path and posing a threat to marine life.
⚠️ Even creatures that have adapted to the harsh Antarctic winter can be caught off guard by the sudden formation of ice rivers.

Q & A

What happens to Antarctica during the winter season?
-In winter, Antarctica doubles in size due to the freeze-up, making it bigger than the USA.
Why is the freezing of the sea around Antarctica an urgent problem for a Weddell seal?
-The Weddell seal faces an urgent problem because her breathing hole begins to freeze over, and without it, she would suffocate.
How does a Weddell seal keep her breathing hole from freezing over?
-The Weddell seal uses her teeth to keep the breathing hole open and prevent it from freezing over.
What is the temperature difference between the sea surface and the underwater environment in Antarctica?
-The underwater environment is a constant two degrees centigrade, which is over 50 degrees warmer than the surface.
How long has the underwater environment in Antarctica been stable at two degrees centigrade?
-The underwater environment has been stable at two degrees centigrade for 25 million years.
What is described as the 'enchanted kingdom' in the script?
-The 'enchanted kingdom' refers to the protected underwater environment beneath the layer of ice in Antarctica, which is a wonderland of strange and beautiful life.
What is a briner, as mentioned in the script?
-A briner is a cold, supercooled water that sinks from above, forming a pillar of ice that can be deadly to the creatures of the seabed.
How does the temperature drop on the surface of Antarctica affect the underwater environment?
-As temperatures plummet on the surface, it triggers the growth of briners, which are like stealthy fingers of death for the creatures of the seabed.
What is the impact of a river of ice on the creatures that live in the underwater environment of Antarctica?
-A river of ice can imprison everything in its path, even those creatures that have adapted to the extreme conditions of the Antarctic winter.
What is the significance of the stable underwater environment for the life in Antarctica?
-The stable underwater environment provides a safe and stable world for life to thrive, allowing for an explosion of life forms despite the harsh conditions on the surface.

Outlines

00:00

🐋 Antarctic Winter's Impact on Weddell Seals

The video script describes the dramatic expansion of Antarctica during winter, which doubles the continent's size, making it larger than the USA. A Weddell seal faces the urgent challenge of keeping her breathing hole from freezing over as the sea around her solidifies. To prevent suffocation, she uses her teeth to maintain an open hole. The script contrasts the cold surface with the warmer, stable underwater environment that has remained at a constant two degrees Celsius for millions of years, fostering a thriving marine ecosystem. However, even this sanctuary is threatened by the winter's deep chill, which triggers the formation of 'briners'—cold, supercooled water that sinks and creates deadly ice pillars, endangering the seabed's inhabitants.

Mindmap

Keywords

💡Freeze up

Freeze up refers to the process by which a body of water, such as the sea surrounding Antarctica, becomes frozen. In the context of the video, the freeze up is depicted as a spectacular event that significantly increases the continent's size during winter. This phenomenon is crucial as it affects the habitat and survival of marine life, particularly the Weddell seal, which relies on open breathing holes in the ice.

💡Weddell seal

The Weddell seal is a species of earless seal native to the Antarctic region. The video highlights the seal's struggle to maintain a breathing hole in the ice as the sea freezes. This showcases the seal's adaptability and resilience in the harsh Antarctic environment, which is a central theme of the video, emphasizing the challenges faced by wildlife in extreme conditions.

💡Breathing hole

A breathing hole is a hole in the ice through which marine mammals, like the Weddell seal, can surface to breathe. The video script describes how the seal uses its teeth to keep the hole open, illustrating the critical role these holes play in the survival of ice-dependent species during the Antarctic winter.

💡Supercooled water

Supercooled water is water that is below its freezing point but has not yet solidified. In the video, the concept is used to describe the formation of 'briners,' which are pillars of ice that form as supercooled water sinks from above. This phenomenon is depicted as a threat to the marine life, encapsulating the video's theme of the dual nature of the Antarctic environment as both a sanctuary and a place of hidden dangers.

💡Briner

A briner is a column of cold, supercooled water that sinks in the ocean and can freeze upon contact with the colder seabed, creating a pillar of ice. The video uses the term to illustrate the dynamic and sometimes perilous nature of the Antarctic underwater environment, where even the most adapted creatures can be caught off guard by the sudden formation of ice.

💡Seabed

The seabed refers to the bottom of a sea or ocean, which in the video is described as a 'stealthy finger of death' due to the formation of briners. This term is central to the video's narrative as it highlights the hidden dangers that exist beneath the surface, even in a seemingly stable and safe environment.

💡Enchanted kingdom

The term 'enchanted kingdom' is used poetically in the video to describe the underwater world beneath the Antarctic ice. It suggests a realm of beauty and wonder, teeming with life, which contrasts with the harsh and inhospitable surface conditions. This phrase captures the video's portrayal of the Antarctic as a place of paradoxical extremes.

💡Temperature extremes

Temperature extremes refer to the significant differences in temperature between the Antarctic surface and the underwater environment. The video emphasizes these extremes by comparing the warmer, stable conditions of the sea with the freezing temperatures at the surface, highlighting the video's theme of survival in a land of contrasts.

💡Sinister

In the context of the video, 'sinister' is used to describe the briners and the threat they pose to marine life. It conveys a sense of danger and foreboding, adding a dramatic tone to the video's narrative about the challenges faced by Antarctic wildlife.

💡Life explodes

The phrase 'life explodes' is used to describe the abundance and diversity of marine life in the Antarctic underwater environment. It suggests a vibrant ecosystem that flourishes despite the harsh conditions above, reinforcing the video's message of resilience and adaptation in extreme environments.

💡Winter cold

Winter cold in the video refers to the extreme cold temperatures that characterize the Antarctic winter. It is depicted as a force that can disrupt the stability of the underwater environment, triggering the formation of briners and affecting the survival of marine life. This term is integral to the video's exploration of the impact of seasonal changes on the Antarctic ecosystem.

Highlights

In Antarctica, the freeze-up dramatically increases the continent's size, doubling it in winter.

The continent's expanded size during winter is larger than the USA.

A Weddell seal faces an urgent problem as her breathing hole begins to freeze over.

The seal uses her teeth to keep her breathing hole from freezing, ensuring survival.

The sea provides a warmer retreat for the seal, with a constant temperature of two degrees Celsius.

The underwater environment is over 50 degrees warmer than the surface.

The sea's stable temperature has been maintained for 25 million years.

Beneath the ice, an enchanted kingdom is protected from the extreme surface temperatures.

The underwater world is a wonderland of strange and beautiful life.

Life flourishes in the safe and stable underwater environment.

Winter's cold can still impact the underwater world, causing changes in the ecosystem.

Supercooled water sinking from above forms briners, which are cold and dangerous.

Briners are a stealthy threat to the seabed creatures, acting as a finger of death.

A river of ice can imprison and kill everything in its path.

Even creatures adapted to extreme conditions can be caught out by the winter's icy grip.