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

Summary

In 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.